sodium-hypochlorite and Smear-Layer

This systematic review aims to analyse the available evidence concerning the use of citric acid (CA) in endodontics treatment and to assess its results in terms of different considerations: effect on smear layer removal, influence on sealer bond strength, activation effect by means of sonic or ultrasonic devices, effects on dentine surface, antibacterial activity, and effectiveness boost for regenerative procedures, releasing growth factors from dentin. To evaluate the results of CA as a final irrigant and compare them to other chelating agents. This review followed the PRISMA checklist. An electronic search was conducted in MEDLINE (OVID), Scopus (Elsevier) and the Web of Science (Thomson Reuters) databases. Risk of bias of included studies was evaluated using the modified CONSORT checklist and the PRIRATE checklist 2020 guidelines. 39 studies fulfilled the eligibility criteria to be included in this review: 27 in vitro studies using extracted human teeth, 10 in vitro studies using human dentin disks, and 2 RCT. Citric acid has proven to be effective in smear layer removal, showing better results in coronal and middle root thirds, improving its effect when combined with manual dynamic activation. There is no agreement regarding citric acid effect on sealer adhesion and adaptation to root canal walls due to heterogeneity within studies. Citric acid irrigation can decrease dentine microhardness and cause decalcification and erosion, especially when used before NaOCl. Citric acid has proven to be beneficial in regenerative endodontic procedures due to higher TGF-β1 release.Trial registration: Prospero database CRD42021267055.

Topics: Citric Acid; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Ultrasonically-activated irrigation (UAI) is effective in root canal irrigation but may damage canal walls. EDDY is a sonic activation system with flexible working tips that cause no harm to dentinal walls. This review explores the intracanal cleaning efficacy of EDDY compared with UAI in vitro.. The systematic review was registered in the PROSPERO database (CRD42021235826). A literature search was conducted in six electronic databases. In vitro studies that compared the removal of smear layer, debris, soft tissue or microbes in root canals between EDDY and UAI were included. Data extraction and quality assessment were performed. Meta-analyses were conducted on smear layer removal and debris elimination with the standardized mean difference (SMD). Heterogeneity was measured using the I. 19 articles were included in this systematic review and 7 articles were included in meta-analyses. Meta-analyses on smear layer removal showed unimportant differences between EDDY and UAI at any canal third (coronal [SMD = 0.08, 95% confidence interval (95%CI): -0.29 to 0.45; p = 0.44, I. Limited evidence indicated that EDDY was comparable to UAI in removing smear layer, debris, soft tissue and microbes ex vivo. Considering UAI may damage canal walls, EDDY might be a substitute for UAI in irrigation activation. But more randomized clinical trials are required to explore the clinical extrapolation of the results in this review.

Topics: Dental Pulp Cavity; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

To ensure a successful endodontic treatment, it is important to have a proper disinfection of the root canal. The current study compares the root canal cleanliness and smear layer score between sonic and ultrasonic activation.. Systematic literature review was implemented, using 12 databases. All. At the apical level, pooling the data in the random-effects model (I. Sonic activation accomplished advancement relative to ultrasonic agitation in removing the smear layer, while ultrasonic activation resulted in significant cohesion between the sealers and the dentine tubules, decreasing the vulnerability of apical leakage and tooth fracture.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

This systematic review aimed to compare the efficacy of herbal agents with ethylene diamine tetraacetic acid (EDTA) in removing the smear layer during root canal instrumentation. The research question in the present study was to assess: "Is there a significant difference in reducing smear layer comparing EDTA and herbal agents?" Electronic databases (PubMed, Scopus, and Web of Science) were searched from their start dates to April 2022 using strict inclusion and exclusion criteria, and reviewed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines. Only in vitro studies comparing herbal agents with EDTA were included in the current systematic review. Two reviewers independently assessed the included articles. A total of 625 articles were obtained from an electronic database. Eighteen papers were included for review of the full text, out of which, ten papers were excluded because they did not meet the inclusion criteria. Finally, eight articles were included in the systematic review. The present systematic review considered only in vitro studies; hence, the result cannot be completely translated to strict clinical conditions. The results of the present systematic review have shown that

Topics: Acetic Acid; Chelating Agents; Edetic Acid; Ethylenes; Humans; Microscopy, Electron, Scanning; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The purpose of this review is to address the smear layer removing the ability of root different canal irrigants including ethylenediaminetetraacetic acid (EDTA), a mixture of tetracycline, acid and detergent (MTAD), tetraclean, citric acid, Q-Mix, maleic acid, and smear clear.. Smear layer is a layer which is produced during instrumentation. It contains both organic and inorganic materials. It may also contain bacteria and their byproduct considering the root canal situation. This layer may prevent the penetration of the healing material introduced to the canal to the interior of the dentinal tubules. In addition, it can affect the adaptation of sealing materials to the root canal walls.. The smear layer removal ability of MTAD is superior and faster than EDTA. Tetraclean is similarly composed of an acid, an antibiotic, and a detergent. The presence of doxycycline is believed to help the smear layer removal ability of these irrigants. Antibiotics such as tetracycline had similar smear layer removal ability as even citric acid. EDTA is an amino acid with a chelating ability that sequestrates metal ions. Some believed EDTA smear layer removing ability is better than MTAD, tetraclean, SmearClear, and 20% citric acid which is controversial in case of comparison between MTAD and EDTA. Phosphoric acid is efficient enough to be comparable to EDTA in removing the smear layer. Maleic acid is an organic compound with acid etching smear layer removal. Its ability seems to be similar or even better than EDTA. Citric acid as another organic acid is believed to be used as smear removing agent. HEBP is another chelating agent that can be used in combination with NaOCl; however, HEBP is a weak decalcifying agent compared to EDTA and hence cannot be applied as a mere final rinse. QMiX is a combination of CHX, EDTA, and detergent and should be used at final rinse. It is believed that QMiX is as efficient as EDTA. Smear clear is a 17% EDTA solution including an anionic and cationic (cetrimide) surfactant. The ability of QMiX is similar to EDTA.. There are different canal irrigation solutions with various smear layer removal ability that some should be used as a mere final rinse and some should not.. The usage of canal irrigation solutions depends on the clinical situation and preference of the dentists. This study provides a good guide for clinician of the field.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

Mechanical instrumentation preparation alone is insufficient to completely remove root canal infection, and chemical irrigation is essential to eliminate infected remnants. An ideal root canal irrigant should completely remove the smear layer, lubricate the root canal, efficiently kill bacteria, induce mild or no inflammatory response in the tissues, and avoid damaging the dentin structure. However, a commercial irrigant that meets all these requirements is currently lacking. QMix is a root canal irrigation mixture of ethylenediamine tetraacetic acid (EDTA), chlorhexidine (CHX) and surfactant. This mixture can remove the smear layer efficiently, and it possesses strong antibacterial effect and good biocompatibility with minimal cytotoxicity. Furthermore, the influence of QMix on the color and micro-hardness of dentin is low, and it can improve the wettability of root canal sealant without affecting its adhesive properties. This review compares the efficiencies of QMix with other irrigants (sodium hypochlorite, CHX, EDTA, SmearClear, and MTAD) in term of smear layer removal, dentine and root canal sealing, cell cytotoxicity, and bacterial growth inhibition.. 根管预备时，采用单纯机械预备方法无法完全去除根管内感染，化学冲洗是消除根管内感染不可或缺的步骤。理想的根管冲洗剂应具备彻底清除玷污层、润滑根管、有效杀菌、对组织无毒性且不损伤牙齿结构的特点。现有的根管冲洗剂尚不能同时满足上述所有要求。QMix是由乙二胺四乙酸（EDTA）、氯己定（CHX）和表面活性剂混合组成的根管冲洗剂。QMix能够有效去除玷污层，杀菌性强且有持续的抗菌作用，细胞毒性小且生物相容性好，对牙本质的着色浅，对牙本质微硬度的影响小。此外，QMix还可以提高根管封闭剂的润湿性且不影响其粘接性能。本文比较QMix与其他常用的根管冲洗剂（如次氯酸钠、CHX、EDTA、SmearClear、MTAD等）在去除玷污层、对牙本质作用、对根管封闭剂的影响、细胞毒性、抗菌作用等方面的作用特点，将目前对QMix的研究成果作一综述。.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite

Chlorine-containing solutions are used for broad disinfection purposes. Water disinfection literature suggests that their disinfectant action depends on pH values as this will influence the available free chlorine forms. Hypochlorous acid (HOCl) has been suggested to have an antimicrobial effect around 80-100 times stronger than the hypochlorite ion. The aim of this paper was to review the influence of pH changes on the efficacy of chlorine-containing endodontic irrigating solutions. An electronic and hand search (articles published through to 2010, including 'in press' articles; English language; search terms 'root canal irrigants AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution'; 'antimicrobial action AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution'; 'tissue dissolution AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution'; 'smear layer AND sodium hypochlorite or hypochlorous acid or superoxidized water or electrochemically activated solution') was performed to identify publications that compared chlorine water solutions with different pH. Of 1304 publications identified, 20 were considered for inclusion in the review. The search resulted in the retrieval of articles studying sodium hypochlorite (NaOCl), superoxidized waters (SOW) and sodium dichloroisocyanurate (NaDCC). Regarding antimicrobial efficacy, the literature suggested that reducing the pH value of NaOCl to between 6 and 7.5 would lead to improved action; SOW was described as having a lower antimicrobial effect. The tissue dissolution activity NaOCl decreased when the pH reached values between 6 and 7.5; NaDCC and SOW had no clinically relevant tissue dissolution capability. Chlorine solutions of different characteristics appeared to have some cleaning efficacy although they should to be used in conjunction with chelating and/or detergent agents.

Topics: Anti-Infective Agents; Chlorine; Disinfection; Electrochemical Techniques; Humans; Hydrogen-Ion Concentration; Hypochlorous Acid; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

Root canal instrumentation produces a layer of organic and inorganic material called the smear layer that may also contain bacteria and their by-products. It can prevent the penetration of intracanal medicaments into dentinal tubules and influence the adaptation of filling materials to canal walls. This article provides an overview of the smear layer, focusing on its relevance to endodontics. The PubMed database was used initially; the reference list for smear layer featured 1277 articles, and for both smear layer dentine and smear layer root canal revealed 1455 publications. Smear layer endodontics disclosed 408 papers. A forward search was undertaken on selected articles and using some author names. Potentially relevant material was also sought in contemporary endodontic texts, whilst older books revealed historic information and primary research not found electronically, such that this paper does not represent a 'classical' review. Data obtained suggests that smear layer removal should enhance canal disinfection. Current methods of smear removal include chemical, ultrasonic and laser techniques - none of which are totally effective throughout the length of all canals or are universally accepted. If smear is to be removed, the method of choice seems to be the alternate use of ethylenediaminetetraacetic acid and sodium hypochlorite solutions. Conflict remains regarding the removal of the smear layer before filling root canals, with investigations required to determine the role of the smear layer in the outcomes of root canal treatment.

Topics: Edetic Acid; Humans; Lasers, Solid-State; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Ultrasonics

Local wound debridement in the diseased pulp space is the main step in root canal treatment to prevent the tooth from being a source of infection. In this review article, the specifics of the pulpal microenvironment and the resulting requirements for irrigating solutions are spelled out. Sodium hypochlorite solutions are recommended as the main irrigants. This is because of their broad antimicrobial spectrum as well as their unique capacity to dissolve necrotic tissue remnants. Chemical and toxicological concerns related to their use are discussed, including different approaches to enhance local efficacy without increasing the caustic potential. In addition, chelating solutions are recommended as adjunct irrigants to prevent the formation of a smear layer and/or remove it before filling the root canal system. Based on the actions and interactions of currently available solutions, a clinical irrigating regimen is proposed. Furthermore, some technical aspects of irrigating the root canal system are discussed, and recent trends are critically inspected.

Topics: Anti-Infective Agents, Local; Bacteria, Anaerobic; Chelating Agents; Chlorhexidine; Dental Pulp Cavity; Edetic Acid; Humans; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Calcium hydroxide has found its use in endodontic treatments. On the other hand, chlorhexidine is more and more proposedfor uses in clinical endodontics. Could chlorhexidine surpass calcium hydroxide and what are the benefits of chlorhexidine? This literature overview concludes that both medications are useful and that further studies are necessary before chosing one above the other.

Topics: Bacteria; Calcium Hydroxide; Chlorhexidine; Dentin; Drug Combinations; Humans; Pain, Postoperative; Periapical Periodontitis; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

When the root canals are instrumented during endodontic therapy, a layer of material composed of dentine, remnants of pulp tissue and odontoblastic processes, and sometimes bacteria, is always formed on the canal walls. This layer has been called the smear layer. It has an amorphous, irregular and granular appearance under the scanning electron microscope. The advantages and disadvantages of the presence of smear layer, and whether it should be removed or not from the instrumented root canals, are still controversial. It has been shown that this layer is not a complete barrier to bacteria and it delays but does not abolish the action of endodontic disinfectants. Endodontic smear layer also acts as a physical barrier interfering with adhesion and penetration of sealers into dentinal tubules. In turn, it may affect the sealing efficiency of root canal obturation. When it is not removed, the durability of the apical and coronal seal should be evaluated over a long period. If smear layer is to be removed, EDTA and NaOCl solutions have been shown to be effective, among various irrigation solutions and techniques, including ultrasonics, that have been tested. Once this layer is removed, it should be borne in mind that there is a risk of reinfecting dentinal tubules if the seal fails. Further studies are needed to establish the clinical importance of the absence or presence of smear layer.

Topics: Chelating Agents; Dental Leakage; Dentin Permeability; Edetic Acid; Humans; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy

Disinfection is a key aspect in the preparation of root canals prior to obturation. Irrigation and intracanal medicaments are the chemical means of debridement. The bacterial role is significant, and intracanal medicaments must be cidal in their effect on bacteria and the dentinal tubules. Topical application of medicaments seem to be as effective or more effective than antibiotic applications. Glutaraldehyde and calcium hydroxide are two of the more recently studied medicaments. Calcium hydroxide shows promise as an effective microbicide. The importance of removal of bacteria and necrotic debris from the canal by chemomechanical means--mechanical preparation, cidal irrigation, antimicrobial medicaments--will enhance the successful outcome of endodontic therapy.

Topics: Calcium Hydroxide; Dental Pulp Cavity; Dentin; Glutaral; Humans; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite

This research aimed to assess the efficacy of different irrigants applied with different types of needle tips on smear layer removal (SLR) in primary incisors. This study was carried out with 35 freshly extracted upper primary incisors. The samples were randomly distributed to five study groups (n = 7) (1 to 4: experimental, 5: control). These included Group 1: 5% Ethylenediaminetetraacetic Acid (EDTA) + 1% Sodium Hypochlorite (NaOCl) applied with open-ended needle (OEN), Group 2: 6% Citric Acid (CA) + 1% NaOCl applied with OEN, Group 3: 5% EDTA + 1% NaOCl applied with double side-vented needle (DSVN), Group 4: 6% CA + 1% NaOCl applied with DSVN and Group 5: 1% NaOCl applied with OEN. Accordingly, the inner root surfaces were examined using scanning electron microscopy (SEM). The differences between the groups were analyzed using Kruskal-Wallis, Friedman and Siegel-Castellan tests (

Topics: Citric Acid; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Topics: Dental Leakage; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth, Deciduous

This study aimed to compare the EndoVac system and conventional needle irrigation in removing smear layer (SR) from primary molar root canals.. Fifty extracted human primary second molar roots were instrumented up to an apical size of 0.04/35 and randomly divided into two main groups; Group 1: EndoVac system (n = 25) and Group 2: Conventional needle irrigation (n = 25) and three subgroups (a) NaOCl + ethylenediaminetetraacetic acid (EDTA) (n = 20) (b) ozonated water (OW) + EDTA (n = 20) and (c) saline (control, n = 10). After a standardized final irrigation protocol performed for all teeth, scanning electron microscope images were taken at ×1000 magnification for each thirds of each root canal. Data were analyzed by the weighted kappa, Kruskal-Wallis, and Wilcoxon signed rank tests.. EndoVac was more effective than conventional needle in the removal of SR from the apical third of the root canal system (P < 0.05). The OW + EDTA regimen provided similar SR removal compared with NaOCl + EDTA.. EndoVac has better performance than conventional needle irrigation in the removal of the SR in the apical thirds of the primary molar root canals. As a final irrigation regimen, the OW + EDTA regimen is as effective as the NaOCl + EDTA regimen.

Topics: Debridement; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Molar; Needles; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Tooth, Deciduous; Vacuum

This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid (EDTA) on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups: control group (group A) was given 2.5% NaOCl, and 4 experimental groups were given 2.5% NaOCl and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning electron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A (P>0.05). In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups (P>0.05), but there was significant difference in removal of smear layer between group C and group B (P<0.05). Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D (P<0.01). There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOCl could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.

Topics: Adolescent; Bicuspid; Chelating Agents; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Solutions; Time Factors; Treatment Outcome; Young Adult

This study sought to present a standardized biofilm model in extracted teeth with an artificial apical groove to quantify the efficacy of hand, rotary nickel-titanium, and self-adjusting file (SAF) instrumentation in biofilm bacteria removal.. Thirty-six extracted single-rooted teeth with oblong canals were selected. Each tooth was split longitudinally, and a 0.2-mm-wide groove was placed in the apical 2 to 5 mm of the canal. After growing mixed bacteria biofilm inside the canal under an anaerobic condition, the split halves were reassembled in a custom block, creating an apical vapor lock. Teeth were randomly divided into 3 treatment groups (n = 10 per group) using the K-file, ProFile (Dentsply Tulsa Dental Products, Tulsa, OK), and the SAF (ReDent-Nova, Ra'anana, Israel). Irrigation consisted of 10 mL 3% NaOCl and 4 mL 17% EDTA. Six teeth received no treatment. Areas inside and outside the groove were examined using a scanning electron microscope.. The scanning electron microscope showed a consistently thick layer of biofilm grown in the canals of the control group after 4 weeks. Within the groove, a smaller area remained occupied by bacteria after the use of the SAF compared with the ProFile and the K-file (3.25%, 19.25%, and 26.98%, respectively; P < .05). For all groups, significantly more bacteria were removed outside the groove than inside (P < .05). No statistical differences were found outside the groove (P > .05).. Although all techniques equally removed bacteria outside the groove, the SAF reduced significantly more bacteria within the apical groove. No technique was able to remove all bacteria. This biofilm model represents a potentially useful tool for the future study of root canal disinfection.

Topics: Bicuspid; Biofilms; Dental Alloys; Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; Microscopy, Electron, Scanning; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Time Factors; Titanium; Tooth Apex

Aim of this study was to evaluate the effect of 7% maleic acid and 17% ethylenediaminetetraacetic acid (EDTA) on the shear bond strength of RealSeal SE sealer to root canal dentin. Twenty incisors were split into coronal, middle and apical third and were treated in the following manner: Group 1: 5 ml of saline (1 minute). Group 2: 2.5% sodium hypochlorite (5 ml/min) followed by 79% maleic acid (5 ml/min). Group 3: 2.5% sodium hypochlorite (5 ml/min) followed by 17% EDTA (5 ml/min). Sealer was the placed on the root dentin and samples were subjected to bond strength measurement. There was no significant difference in bond strength between maleic acid and 17% EDTA in coronal & middle third. However, in apical third, 7% maleic acid showed higher bond strength. Least bond strength was observed with saline. Bond strength was maximum in apical third for both 7% maleic acid and 17% EDTA.

Topics: Adhesiveness; Composite Resins; Dental Bonding; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Maleates; Materials Testing; Root Canal Irrigants; Shear Strength; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Stress, Mechanical; Tooth Apex

To evaluate the influence of calcium hydroxide (CH) paste used as intracanal medication on the bond strength of AH Plus (AH) and Epiphany (EP) sealers to root dentin.. Sixty palatal canals were prepared in human maxillary first molars, using a rotary system. Half of the specimens received distilled water, and the other ones received intracanal medication with CH for 14 days. Thereafter, the CH was removed and both groups were further divided into two subgroups, filled with either AH or EP. The test specimens were submitted to the micropush-out test at a speed of 0.5 mm min(-1) . Results were statistically analyzed with anova and Tukey's test at a 95% confidence level.. The use of CH had statistically significant (P < 0.05) influence on AH only, increasing its bond strength from 19.7 ± 4.5 to 23.8 ± 2.5 (mean ± SD in MPa). In both EP groups, with (1.8 ± 0.5 MPa) and without (1.5 ± 0.9 MPa) CH, the bond strength values were statistically significantly lower than in either of the AH groups (P < 0.05).. Calcium hydroxide used as intracanal medication for 14 days had a positive influence on the bond strength of AH to root dentin whereas the effect on EP was insignificant. Regardless of the intracanal medication used, AH showed considerably higher bond strength values compared with EP sealer.

Topics: Calcium Hydroxide; Dental Bonding; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Epoxy Resins; Glass Ionomer Cements; Humans; Humidity; Image Processing, Computer-Assisted; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Temperature; Time Factors

  To assess the bond strength of Epiphany and AH Plus sealers to root canal walls using a push-out test after use of several endodontic irrigants..   Roots of 100 maxillary canines were sectioned horizontally 5 mm below the cemento-enamel junction to provide 4-mm-thick dentine disks that were embedded in acrylic resin and had their root canals prepared with a tapered bur (larger diameter=2.70 mm; smaller diameter=2.30 mm; length = 4 mm). The specimens were randomly assigned to five groups (n=20) according to the dentine surface treatment: I - 1% NaOCl (30 min); II - 1% NaOCl (30 min) + 17% EDTA (5 min); III - 17% EDTA (30 min); IV - 24% EDTA gel (30 min); V - 2% chlorhexidine gluconate (CHX) gel (30 min). In each group, two specimens were prepared for scanning electron microscopy to examine the surface of root canal dentine after use of each irrigant. The other 18 specimens were filled with AH plus (n = 9) or Epiphany (n=9) and subjected to a push-out test in an Instron machine. Data (in MPa) were subjected to statistical analysis by two-way anova and post-hoc Tukey-Kramer test (P < 0.05)..   AH Plus had a significantly higher bond strength (8.74 ± 2.75) than Epiphany (6.74 ± 3.97) (P < 0.05). One per cent NaOCl/17% EDTA was associated with significantly higher bond strength values (10.88 ± 3.05) than the other irrigants (P < 0.05). Seventeen per cent EDTA (8.75 ± 1.75), 24% EDTA gel (7.48 ± 3.48) and 2% CHX gel (7.89 ± 3.41) had intermediate values that were not significantly different from each other (P > 0.05). One per cent NaOCl was associated with the lowest mean values (3.70 ± 0.86) (P < 0.05). The interaction between surface treatment and sealer revealed significantly higher bond strength for 24% EDTA gel with AH Plus, 2% CHX gel with AH Plus and 1%NaOCl/17%EDTA with Epiphany (P < 0.05)..   Except for 1% NaOCl, the removal of smear layer with the other irrigants increased the bond strength of AH Plus to intracanal dentine. The use of 1% NaOCl for 30 min with 17% EDTA as final irrigant for 5 min increased the bond strength of Epiphany.

Topics: Adhesiveness; Chlorhexidine; Dental Bonding; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Edetic Acid; Epoxy Resins; Gels; Humans; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Time Factors

The purpose of this study was to evaluate the effect of three different irrigating solutions (17% EDTA, 10% citric acid and 2.5% NaOCl) and KTP laser irradiation on apical leakage using an electrochemical method.. Sixty extracted single-rooted human teeth with mature apices were instrumented up to a size 35 K-file. After using each file and before proceeding to the next, canals were irrigated with 2 ml of 2.5% NaOCl. All teeth were then randomly divided into four groups. In group 1, the root canals were irrigated with a final flush of 17% EDTA. In group 2, the root canals were irrigated with a final flush of 10% citric acid. In group 3, the root canals were irradiated with KTP laser at 1 W, 4.45 J/cm(2). In group 4, the root canals were irrigated with a final flush of 2.5% NaOCl. The root canals were then filled using the cold lateral condensation method. Apical leakage was evaluated using an electrochemical method over a period of 10 days. Data were analysed using Tukey HSD and Friedmann tests with p = 0.05 as the level for statistical significance.. The 17% EDTA and 10% citric acid groups had statistically less apical leakage than the 2.5% NaOCl group at days 7, 8, 9 and 10 (p < 0.05); however, no significant differences were found between the tested groups at the other time intervals (p > 0.05). No significant difference was found between the KTP laser group and other groups tested at all time intervals (p > 0.05).. All groups were unable to eliminate apical leakage. However, final irrigation with 17% EDTA and 10% citric acid following root canal preparation reduced postobturation apical leakage compared with 2.5% NaOCl irrigation. When KTP laser and the other three irrigants were compared, no significant difference was found.

Topics: Citric Acid; Dental Leakage; Edetic Acid; Electric Impedance; Electrochemical Techniques; Gutta-Percha; Humans; Humidity; Laser Therapy; Lasers, Solid-State; Materials Testing; Radiation Dosage; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth Apex

To compare the cleaning effectiveness of manual, hybrid and rotary instrumentation techniques in primary molar teeth.. Fifteen primary molars were selected. After endodontic access, the teeth were immersed in a medium containing Enterococcus faecalis and divided into three groups, according to the root canal instrumentation technique: group 1 - manual, group 2 - hybrid and group 3 - nickel-titanium (NiTi) rotary files. For microbiological evaluation, comparisons before and after instrumentation were performed using the paired Student's t-test. One-way anova complemented with the Student's t-test was used to compare the percentage of microbial reduction. Instrumentation time was evaluated by Kruskal-Wallis and Student-Newman-Keuls tests. Images obtained under scanning electron microscopy were analysed by three blinded examiners, and kappa statistics was used to evaluate calibration among examiners. The most frequent results among examiners were analysed using Kruskal-Wallis and Student-Newman-Keuls tests.. The hybrid technique required a significantly longer instrumentation time than the manual and rotary techniques (P < 0.05). All techniques tested were able to significantly reduce the number of E. faecalis (P < 0.05). The hybrid technique was associated with the highest intracanal bacterial reduction, with a statistically significant difference compared with manual instrumentation (P = 0.01). Manual instrumentation resulted in the lowest amount of debris and the highest amount of smear layer when compared with the rotary and hybrid techniques (P < 0.05). There was no difference between rotary and hybrid instrumentation in the removal of debris and smear layer.. The use of NiTi rotary files is an option for root canal instrumentation in primary teeth.

Topics: Bacterial Load; Carbamide Peroxide; Dental Alloys; Dental Pulp Cavity; Dentin; Enterococcus faecalis; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Molar; Nickel; Peroxides; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Titanium; Tooth, Deciduous; Urea

To evaluate the accumulation of hard-tissue debris when using the Self-adjusting File (SAF) system in mesial roots of mandibular molars with isthmuses and to compare it with that occurring when the ProTaper file system was used.. Forty extracted human mandibular molars with joining mesial root canals and an isthmus between the two canals were randomly assigned to two experimental groups and scanned using micro-computed tomography. Root canals in the control group (N = 20) were instrumented using the ProTaper rotary system until F3. Irrigation with 1 mL of 3% NaOCl solution was applied after each instrument. Root canals in the experimental group (N = 20) were prepared using the SAF for 4 min, with continuous irrigation (3% NaOCl, 4 mL min(-1)). After rescanning, canals in both groups were further irrigated with 5 mL of 17% EDTA for 2 min. After final scanning, the per cent value of total canal system volume filled with hard-tissue debris was calculated. Statistical analysis was performed using Mann-Whitney U-test; the alpha-type error was set at 1%.. Instrumentation of the root canals with ProTaper left 10.1% (IQR 5.2) of the total canal system volume filled with hard-tissue debris while preparation with the SAF left 1.7% (IQR 1.6). This difference was highly significant (P < 0.0001). After subsequent EDTA irrigation, these values were significantly reduced (P < 0.01) to 7.9% (IQR 4.1) and 1.3% (IQR 0.8) in the ProTaper and SAF groups, respectively.. Preparation with the SAF system resulted in less hard-tissue debris accumulation in isthmus-containing root canal systems compared with instrumentation with ProTaper rotary files.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Mandible; Materials Testing; Molar; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth Apex; Vibration; X-Ray Microtomography

The effect of smear layer (SL) removal on primary tooth pulpectomy outcome has not been well elucidated.. To determine the effect of SL removal on primary tooth pulpectomy outcome.. This is a double-blind, randomized, and controlled clinical trial. Forty-eight patients were randomly divided into SL removal (G1 = 40 teeth) or smear layer nonremoval (G2 = 42 teeth) groups. Following the chemomechanical preparation with K-files and 2.5% sodium hypochlorite (NaOCl), teeth were irrigated with either 6% citric acid and 0.9% physiologic solution (G1) or only 0.9% physiologic solution (G2). Camphorated paramonochlorophenol was used as intracanal medication. At the second appointment, 1 week after, root canals were filled with zinc oxide-eugenol paste. Clinical and radiographical baseline criteria were stipulated equally for both groups.. The success rate (G1 = 91.2%; G2 = 70.0%) was statistically different (P = 0.04) between the groups. In G2, the outcome was affected significantly by pulpal necrosis (P = 0.02), pre-operatory symptoms (P = 0.02), and periapical/inter-radicular radiolucency (P = 0.04).. The pulpectomy outcome was improved by smear layer removal. The outcome for teeth with pulpal necrosis, pre-operatory symptoms, or periapical/inter-radicular radiolucency was significantly improved by removal of the smear layer.

Topics: Age Factors; Child; Child, Preschool; Citric Acid; Drug Combinations; Female; Humans; Intention to Treat Analysis; Male; Pulpectomy; Radiography; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Tooth, Deciduous; Treatment Outcome

The shaping ability of root canal instruments is determined by a complex interrelationship of parameters such as cross-sectional design and the ability to remove debris and the smear layer. The self-adjusting file (SAF) consists of a hollow, flexible instrument in the form of a compressible, thin-walled, pointed cylinder. The aim of this study was to compare the SAF with the ProTaper rotary file system, evaluating debris and smear layer removal and the presence of bacteria by using microbiological and scanning electron microscopy (SEM) evaluation.. Fifty maxillary premolars were inoculated with Enterococcus faecalis for 30 days and then randomly distributed into 2 groups. Group 1 was prepared with ProTaper rotary instruments and irrigated with 30-gauge side-vented needles. Group 2 was prepared by using the SAF system with continuous irrigation. Bacteriologic samples were taken before and after preparation. All samples were then longitudinally split and analyzed under scanning electron microscopy. The scoring was carried out by 3 blinded evaluators.. In group 1, 40% of samples had negative cultures with postinstrumentation samples taken with paper points (S2a) and 45% with postinstrumentation dentin samples (S2b). In group 2, 20% of samples had negative cultures with S2a and 15% with S2b. Intragroup analyses evaluating the reduction in the number of colony-forming units (CFUs) from S1 to S2a and S2b demonstrated both preparation techniques were highly effective (P < .01). Further reduction of CFUs was observed when comparing S2a and S2b in group 1 (P < .05), whereas no difference was observed in group 2. Intergroup analysis demonstrated a statistically significant difference of CFUs at S2a and S2b (P < .05). SEM scores were consistent with the microbiology findings.. The SAF system does not allow control of the apical enlargement, thus limiting the ability of the irrigants to achieve effective and predictable disinfection.

Topics: Bacterial Load; Bacteriological Techniques; Dental Pulp Cavity; Dentin; Enterococcus faecalis; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Molar; Root Canal Irrigants; Root Canal Preparation; Single-Blind Method; Smear Layer; Sodium Hypochlorite; Surface Properties; Therapeutic Irrigation; Tooth Apex

The objective of this study was to compare the efficacy on smear layer removal of 4 decalcifying agents: 17% ethylenediaminetetraacetic acid (EDTA), 20% citric acid, BioPure MTAD, and SmearClear.. Forty-five single-rooted human teeth were used and prepared up to ProTaper F3. After each instrumentation, 1 mL of 3% NaOCl at 60°C was irrigated for 1 minute. All the samples were randomly divided into 5 groups according to the final irrigants: 17% EDTA, 20% citric acid, BioPure MTAD, SmearClear, and 3% NaOCl (control). The smear layer removal of all groups at the apical, middle, and coronal thirds was observed under the thermal field emission scanning electron microscope.. The EDTA group was significantly more effective than the SmearClear and MTAD groups (P < .05). The efficacy of all three thirds in the EDTA, MTAD, and SmearClear groups can be arranged as coronal, middle, and apical thirds (P < .05) from excellent to poor. However, in the citric acid group, the coronal two thirds were significantly better than the apical third (P < .05), and there was no statistical significance between the coronal and middle thirds (P > .05).. The 4 decalcifying agents could effectively, but not completely, remove the smear layer, especially in the apical third. The efficacy of 17% EDTA was better than that of MTAD and SmearClear.

Topics: Citric Acid; Dental Pulp Cavity; Dentin; Double-Blind Method; Doxycycline; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

The purpose of this study was to evaluate the effect of smear layer on apical seal of endodontically treated teeth.. Sixty freshly extracted human maxillary central incisor teeth were selected and were randomly divided into two experimental groups. Group A of 25 teeth and group B of 25 teeth and a control group of 10 teeth. Cleaning and shaping of the root canals were performed using endodontic K-files up to no. 50 size file in step-back technique. During the process, in root canals of group A, 17% EDTA (ethylenediaminetetraacetic acid) followed by 3% NaOCl (sodium hypochlorite) was used as root canal irrigant. In group B, MTAD (mixture tetracycline citric acid and detergent) was used as a root canal irrigant. In control group, saline was used as root canal irrigant. The root surfaces were then coated with nail polish of both experimental groups and control group. The samples were then immersed in India ink dye for 1 week at 37°C.. The statistical analysis of the results showed that the apical leakage was significantly more in teeth, where smear layer was not removed.. The removal of smear layer improves the longterm apical seal and success of endodontically treated teeth.. The development and maintenance of apical seal is desirable and considered to be a major prerequisite to improve the outcome of root canal treatment.

Topics: Carbon; Citric Acid; Coloring Agents; Dental Bonding; Dentin; Doxycycline; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Polysorbates; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Temperature; Time Factors; Tooth Apex; Tooth, Nonvital

Hard-tissue debris is accumulated during rotary instrumentation. This study investigated to what extent a calcium-complexing agent that has good short-term compatibility with sodium hypochlorite (NaOCl) could reduce debris accumulation when applied in an all-in-one irrigant during root canal instrumentation.. Sixty extracted mandibular molars with isthmuses in the mesial root canal system were selected based on prescans using a micro-computed tomography system. Thirty teeth each were randomly assigned to be instrumented with a rotary system and irrigated with either 2.5% NaOCl or 2.5% NaOCl containing 9% (wt/vol) etidronic acid (HEBP). Using a side-vented irrigating tip, 2 mL of irrigant was applied by 1 blinded investigator to the mesial canals after each instrument. Five milliliters of irrigant was applied per canal as the final rinse. Mesial root canal systems were scanned at high resolution before and after treatment, and accumulated hard-tissue debris was calculated as vol% of the original canal anatomy. Values between groups were compared using the Student's t test (α < .05).. Irrigation with 2.5% NaOCl resulted in 5.5 ± 3.6 vol% accumulated hard-tissue debris compared with 3.8 ± 1.8 vol% when HEBP was contained in the irrigant (P < .05).. A hypochlorite-compatible chelator can reduce but not completely prevent hard-tissue debris accumulation during rotary root canal instrumentation.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Etidronic Acid; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Materials Testing; Root Canal Irrigants; Root Canal Preparation; Single-Blind Method; Smear Layer; Sodium Hypochlorite; X-Ray Microtomography

This study analyzed the in vivo microbiological status of the root canal systems of mesial roots of mandibular molars with primary apical periodontitis after 1- or 2-visit endodontic treatment.. Mesial root canals were instrumented by using either a combination of K3 and LightSpeed instruments (mesiobuccal canals) or the ProTaper system (mesiolingual canals), with 5% NaOCl irrigation. Patency files were used. Smear layer was removed, and a final rinse with 5 mL of 2% chlorhexidine was performed. In the 2-visit group (7 roots, 14 canals), canals were medicated with calcium hydroxide for 1 week and then obturated by using the continuous wave of compaction technique. In the 1-visit group (6 roots, 12 canals), canals were immediately obturated after chemomechanical procedures. Teeth were extracted 1 week after root canal instrumentation and processed for histobacteriologic analysis.. In the 1-visit group, no case was completely free of bacteria; residual bacteria occurred in the main root canal (5 of 6 cases), isthmus (5 of 6), apical ramifications (4 of 6), and dentinal tubules (5 of 6). In the 2-visit group, 2 cases were rendered bacteria-free; residual bacteria were found in the main canal only in 2 cases (none of them with persistent dentinal tubule infection), in the isthmus (4 of 7 cases), and in ramifications (2 of 7). The 2 instrumentation techniques performed similarly. When filling material was observed in ramifications, it was usually intermixed with necrotic tissue, debris, and bacteria.. The 2-visit protocol by using an interappointment medication with calcium hydroxide resulted in improved microbiological status of the root canal system when compared with the 1-visit protocol. Residual bacteria were more frequent and abundant in ramifications, isthmuses, and dentinal tubules when root canals were treated without an interappointment medication. Apical ramifications and isthmuses were never completely filled. The use of an antibacterial interappointment agent is necessary to maximize bacterial reduction before filling.

Topics: Adult; Aged; Anti-Infective Agents, Local; Bacteria; Bacterial Load; Biofilms; Calcium Hydroxide; Chlorhexidine; Dental Alloys; Dental High-Speed Equipment; Dental Pulp Cavity; Dental Pulp Necrosis; Dentin; Equipment Design; Female; Gutta-Percha; Humans; Male; Methylmethacrylates; Middle Aged; Nickel; Periapical Periodontitis; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Titanium; Tooth Apex; Zinc Oxide-Eugenol Cement

The purpose of this study was to compare the effectiveness of debris removal between the Self-Adjusting File (SAF), WaveOne, and K3 file systems in the mesial roots of mandibular molars. In addition, the SAF was tested as a potential adjunct after instrumentation with other systems.. The mesial roots of 30 extracted mandibular molars were mounted in resin by using the K-Kube, sectioned at 2 and 4 mm from working length, and randomly placed into 3 groups: K3 group, sequential preparation with K3 files to an apical size of 35/.04; WaveOne group, preparation with WaveOne primary file; and SAF group, preparation with SAF. Images were taken before instrumentation, after instrumentation, after final irrigation, and after SAF adjunct irrigation. A cleanliness percentage was calculated by using interactive software. Comparisons between groups were analyzed with repeated-measures analysis of variance and post hoc tests (P < .05).. There was no significant difference in canal cleanliness among the groups, but the WaveOne was significantly worse for isthmus cleanliness. Use of the SAF as an adjunct only significantly improved canal cleanliness in the K3 group at the 2-mm level by an average of 1.7%.. There was no difference in canal cleanliness between the 3 file systems; however, the SAF and K3 files performed significantly better than the WaveOne with respect to isthmus cleanliness. When used as a final irrigation adjunct device after instrumentation, the SAF provided a significant improvement only in a subset of the K3 group.

Topics: Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; Imaging, Three-Dimensional; Mandible; Materials Testing; Molar; Photography, Dental; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth Apex; Tooth Root

This in vitro study compared debridement efficacies of a sonic irrigation technique (Vibringe; Cavex Holland BV, Haarlem, The Netherlands) with side-vented needle irrigation (SNI) in the mesiobuccal root of maxillary first molars.. Twenty roots with narrow isthmuses (≤ 1/4 canal diameter) were selected using micro-computed tomography scanning. Collagen solution was injected into canals/isthmuses and reconstituted with NH(4)OH to simulate canal debris. Each root was sealed apically and embedded in polyvinyl siloxane simulating a closed-canal system. Canals were instrumented to size 40/.04 taper 1 mm short of the anatomic apex. The final irrigation was performed with the Vibringe or SNI. Roots were demineralized, sectioned at 6 levels (1.2-3.2 mm) from the anatomic apex, and stained using Masson trichrome stain. The areas occupied by canals and isthmus and the debris-containing areas were statistically analyzed with repeated-measures analyses using "irrigation technique" as the between factor and "canal level" as the within factor (α = 0.05).. Canals had significantly more debris at 1.2 and 1.6 mm (P < .001), but there was no overall difference between the 2 techniques (P = .561). Significant differences were found between the Vibringe and SNI at 2.4, 2.8, and 3.2 mm (P < .05). There was no significant difference in the remaining debris in the isthmus for SNI at all (P > .05). Considerably more debris remained at 1.2 and 2.0 mm for the Vibringe (P < .05). A significant difference was observed between the canal and the isthmus (P < .001).. There is no difference between the Vibringe and SNI in their overall debridement efficacy in apical one third of the mesiobuccal root of maxillary first molars.

Topics: Collagen; Dental Alloys; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Materials Testing; Molar; Needles; Nickel; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Therapeutic Irrigation; Titanium; Tooth Apex; X-Ray Microtomography

The purpose of this in vitro study was to compare a continuous ultrasonic irrigation device (VPro StreamClean System [VSS], Vista Dental Products, Racine, WI) with conventional needle irrigation when used as a final irrigation procedure to debride the apical region of the root canal. The null hypothesis that there is no difference was tested.. Root canals of matched pairs (N = 20) of extracted human teeth were prepared to an apical size of 36/.04 using Profile series 29/.04 rotary files (Dentsply Tulsa Dental, Tulsa, OK) with 6% sodium hypochlorite (NaOCl) irrigation. One tooth of each pair was randomly assigned to receive final irrigation with either VSS or conventional needle irrigation. The gauge of the needle (#30), the irrigation cycles (ie, 5 mL NaOCl, 5 mL 15% EDTA, and 5 mL NaOCl), the irrigant flow rate (5 mL/min), and needle depth placement (1 mm from the working length [WL]) were experimental constants. Serial sections were obtained at 1 and 3 mm from the WL, stained with hematoxylin-eosin, and viewed at 100× magnification for the presence of debris. The percentage of debris in the canal lumen after VSS or conventional needle irrigation was compared by using the Wilcoxon matched pairs test.. There was significantly less debris in the VSS group compared with the conventional needle irrigation group at the 1-mm level (1.50% [VSS] vs 9.90% [conventional needle irrigation], P = .0001) and the 3-mm level (0.45% [VSS] vs 5.16% [conventional needle irrigation], P = .0014). The null hypothesis was rejected.. Final irrigation with the VSS compared with conventional needle irrigation delivery resulted in significantly less debris present in root canals at 1 and 3 mm from the WL.

Topics: Dental Alloys; Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; Image Processing, Computer-Assisted; Materials Testing; Needles; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stainless Steel; Therapeutic Irrigation; Titanium; Tooth Apex; Ultrasonics

This study evaluated the protocols of sonic and vacuum irrigation regarding the capacity of debris removal from root canal systems. Canal preparations were carried out on 30 mandibular first molars using the ProTaper Universal System. Teeth were divided into two experimental groups (n=15): Group 1: sonic irrigation and Group 2: vacuum irrigation protocol. Subsequently, the mesial roots were sectioned and observed by stereomicroscopy and scanning electron microscopy. Three independent examiners evaluated images of the apical thirds according to the following scores: 1= small presence of debris, 2= moderate presence of debris, and 3= dense presence of debris. Data were analyzed with ANOVA and Kruskal-Wallis tests (α=0.05). Comparison among the groups revealed that at the apical third, the root halves of Group 1 had significantly less surface debris (p=0.002) than those of Group 2. However, at 2 mm from the working length, Group 2's specimens showed less remaining debris in approximately 75% of the analyzed root canals. At the whole apical third, the sonic irrigation protocol removed significantly more debris than the vacuum protocol. However, in the region at 2 mm from the working length, the second irrigation method demonstrated a better performance.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Image Processing, Computer-Assisted; Microscopy; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Sonication; Therapeutic Irrigation; Tooth Apex; Vacuum

The aim of this preliminary study was to verify the antibacterial potential of cetylpyridinium chloride (CPC) in root canals infected by Enterococcus faecalis. Forty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. The teeth were randomly assigned to the following groups: 1: Root canal preparation (RCP) + 0.1% CPC with positive-pressure irrigation (PPI, Conventional, NaviTip(®)); 2: RCP + 0.2% CPC PPI; 3: RCP + 2.5% NaOCl PPI; 4: RCP + 2.5% NaOCl with negative-pressure irrigation system (NPI, EndoVac(®)); 5: Positive control; and 6: Negative control. Four teeth of each experimental group were evaluated by culture and 4 by scanning electron microscopy (SEM). In all teeth, the root canals were dried and filled with 17% EDTA (pH 7.2) for 3 min for smear layer removal. Samples from the infected root canals were collected and immersed in 7 mL of Letheen Broth (LB), followed by incubation at 37°C for 48 h. Bacterial growth was analyzed by turbidity of culture medium and then observed with a UV spectrophotometer. The irrigating solutions were further evaluated for antimicrobial effect by an agar diffusion test.The statistical data were treated by means, standard deviation, Kruskal-Wallis test and analysis of variance. Significance level was set at 5%. The results showed the presence of E. faecalis after root canal sanitization. The number of bacteria decreased after the use of CPC. In the agar diffusion test, CPC induced large microbial inhibition zones, similar to 2% chlorhexidine and large than 2.5% NaOCl. In conclusion, cetylpyridinium chloride showed antibacterial potential in endodontic infection with E. faecalis.

Topics: Anti-Infective Agents, Local; Bacterial Load; Bacteriological Techniques; Cetylpyridinium; Dental Pulp Cavity; Edetic Acid; Enterococcus faecalis; Humans; Immunodiffusion; Materials Testing; Microscopy, Electron, Scanning; Nephelometry and Turbidimetry; Pressure; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Spectrophotometry, Ultraviolet; Temperature; Therapeutic Irrigation; Time Factors

Sodium hypochlorite solutions have been evaluated for their effects in bonding procedures as they are found to deplete or remove the organic portion of the dentin, particularly the collagen fibrils. The aim of this in vitro study was to assess and compare the efficacies of 1%, 2.5%, 5% and 10% NaOCl at 30, 60 and 120s on etched primary dentin.. 84 primary anterior teeth were ground to expose a flat dentin area on the buccal surface. The specimens were divided into fourteen groups of six each based on the dentin surface treatment (35% phosphoric acid etching for 7 seconds-AE and/or NaOCl application), NaOCl solution concentrations (1%, 2.5%, 5% and 10%) and time of application (0, 30, 60 and 120s). Specimens were prepared for SEM and photomicrographs were taken of the surface and were scored against a five point scale, based on the smear layer and amount of collagen removed. The scores were submitted to Kruskal-Wallis and Mann Whitney tests.. This study showed the presence of smear layer in the control group. The group treated with Acid Etchant showed a demineralized pattern of dentin with exposure of dentin tubules and collagen fibrils network on the intertubular and peritubular dentin which was not significantly different from the groups treated with 1% and 2.5% NaOCl. Groups treated with 5% NaOCI were not statistically different from each other the surface was corroded but collagen fibrils were not completely depleted. Groups treated with 10% NaOCl were not statistically different from each other and showed complete removal of collagen fibrils with wider tubular apertures and several secondary tubules on peritubular and intertubular dentin.. Higher concentrations of NaOCl solutions (5% and 10%) produced significant changes in the etched primary dentin. The higher the concentration of the NaOCI solution, the lower can be the time for the application of the solution for the complete removal of collagen fibrils.

Topics: Acid Etching, Dental; Collagen; Dentin; Humans; Materials Testing; Microscopy, Electron, Scanning; Phosphoric Acids; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth, Deciduous

The greatest reduction in microhardness of the most superficial layer of dentin of the root canal lumen is desired. The use of chelating agents during biomechanical preparation of root canals removes smear layer, increasing the access of the irrigant into the dentin tubules to allow adequate disinfection, and also reduces dentin microhardness, facilitating the action of endodontic instruments. This study evaluated the effect of different chelating solutions on the microhardness of the most superficial dentin layer from the root canal lumen.. Thirty-five recently extracted single-rooted maxillary central incisors were instrumented, and the roots were longitudinally sectioned in a mesiodistal direction to expose the entire canal extension. The specimens were distributed in seven groups according to the final irrigation: 15% EDTA, 10% citric acid, 5% malic acid, 5% acetic acid, apple vinegar, 10% sodium citrate, and control (no irrigation). A standardized volume of 50 μL of each chelating solution was used for 5 minutes. Dentin microhardness was measured with a Knoop indenter under a 10-g load and a 15-second dwell time. Data were analyzed statistically by one-way analysis of variance and Tukey-Kramer multiple-comparison test at 5% significance level.. EDTA and citric acid had the greatest overall effect, causing a sharp decrease in dentin microhardness without a significant difference (p > .05) from each other. However, both chelators differed significantly from the other solutions (p < .001). Sodium citrate and deionized water were similar to each other (p > .05) and did not affect dentin microhardness. Apple vinegar, acetic acid, and malic acid were similar to each other (p > .05) and presented intermediate results.. Except for sodium citrate, all tested chelating solutions reduced microhardness of the most superficial root canal dentin layer. EDTA and citric acid were the most efficient.

Topics: Acetic Acid; Chelating Agents; Citrates; Citric Acid; Dental Pulp Cavity; Dentin; Edetic Acid; Hardness; Humans; Incisor; Malates; Materials Testing; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Citrate; Sodium Hypochlorite; Time Factors; Water

This study compared the ability of different approaches to supplement the antibacterial effects of chemomechanical preparation in oval-shaped root canals.. Long oval canals from extracted teeth infected with Enterococcus faecalis (ATCC 29212) were chemomechanically prepared up to a 40/04 rotary BioRaCe instrument using 2.5% NaOCl irrigation and then subjected to two supplementary protocols. In the passive ultrasonic irrigation (PUI)/chlorhexidine (CHX) group, canals were subjected to PUI for the activation of NaOCl followed by a final rinse with 0.2% CHX digluconate solution. In the Hedström group, canals received additional Hedström filing directed towards the buccal and lingual canal recesses. Bacteriological samples were taken before and after preparation, after PUI or Hedström instrumentation, and after CHX final rinsing.. Chemomechanical preparation and the supplementary steps promoted a highly significant bacterial reduction (P < .001). Quantitative (reduction in levels) and qualitative (frequency of negative cultures) analyses showed that PUI alone or Hedström filing did not significantly increase bacterial reduction (P > .05). Further rinsing with CHX also failed to significantly increase bacterial elimination when compared with post-PUI samples. However, the cumulative antibacterial effects of PUI and CHX final rinse were effective in significantly reducing bacterial counts to levels below those achieved after preparation (P = .03). This combined PUI/CHX approach also resulted in a significant increase in the incidence of negative cultures (P = .04).. Findings suggest that there may be a benefit of using the PUI for the activation of NaOCl followed by a final rinse with CHX as supplementary steps in the treatment of infected oval-shaped root canals.

Topics: Anti-Infective Agents, Local; Bacterial Load; Biofilms; Chelating Agents; Chlorhexidine; Dental Pulp Cavity; Disinfection; Edetic Acid; Enterococcus faecalis; Equipment Design; Humans; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

The aim of this study was to evaluate Self-Adjusting File (SAF) in the removal of smear layer and impact on the dentin surface using sodium hypochlorite (NaOCl) as an initial irrigation solution at 3 different concentrations combined with 1% EDTA. In addition, the erosive effect of this dual irrigation regime was examined.. Root canal preparations were performed in 30 teeth using the SAF with a continuous irrigation device (Vatea) in a closed system in which the apical foramen was sealed. The vibration mode was on for 5 minutes during the preparation. Three different concentrations of NaOCl (1.3%, 2.6%, and 5.25%) and 1% EDTA were used for continuous irrigation. The final flush was also performed using NaOCl with the vibration mode on. The roots were split longitudinally and subjected to scanning electron microscopy (SEM). The presence of the smear layer was scored using a 5-point scoring system, and the erosive capacity of the irrigants were scored using a 3-point scoring system.. The results showed no significant difference in smear layer removal among different concentrations of NaOCl and among the regions. Clean dentin surfaces were observed in 80%, 70%, and 70% with a score of 1 or 2 of the apical thirds using 1.3%, 2.6%, and 5.25% NaOCl, respectively. The 1.3% and 2.6% NaOCl solutions showed similar erosion patterns on the root canal walls (P > .05); however, 5.25% NaOCl caused severe erosion (P < .05).. When using the SAF with continuous irrigation and vibration, lower concentrations of NaOCl and EDTA can be recommended for efficient clinical removal of the smear layer even in the apical thirds and to avoid excessive erosion of root dentin.

Topics: Adolescent; Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Incisor; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth Apex; Vibration; Young Adult

The aim of this study was to evaluate the effectiveness of F-File with NaOCl on removal of the smear layer. A total of 48 single-rooted teeth were instrumented using crown-down technique with one of the irrigation agents: distilled water, 5.25% NaOCl, RC-Prep, Glyde, MTAD or F-File with NaOCl. The remaining smear layer was scored at cervical, middle and apical thirds of the roots with SEM. In all the canals of experimental groups the coronal sections were cleaner than the middle and apical sections except with distilled water (P<0.001). In the coronal third, intensive smear layer was observed in distilled water, NaOCl and F-File groups and less smear layer in MTAD (P<0.05) and least in RC-Prep and Glyde groups. In the middle third, RC-Prep and Glyde groups had less smear layer than the other groups (P<0.001). In the apical third, there was intensive smear layer in all specimens and statistical analyses showed no significant difference among the groups (P>0.05). The F-file failed to improve the effect of NaOCl in removing smear layer.

Topics: Citric Acid; Dental Pulp Cavity; Dentin; Diamond; Doxycycline; Edetic Acid; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Peroxides; Plastics; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Tooth Apex; Urea; Water; Waxes

Taper is a factor that determines final root canal dimensions and, consequently, the dimensions of the space for the cleaning action of irrigants. Therefore, the aim of the present study was to investigate the influence of taper on root canal cleanliness.. Root canals of 45 mandibular incisors were divided into 3 groups and prepared with GT rotary files to apical preparation size 30 and final taper 0.04, 0.06, and 0.08, respectively. Irrigation with 2.5% NaOCl was performed after each file. The final irrigation sequence was 10 mL 17% ethylenediaminetetraacetic acid, followed by 10 mL 2.5% NaOCl and 10 mL saline solution. The presence of debris and smear layer on root canal walls was evaluated under the scanning electron microscope with the use of a 4-category scale system.. The presence of debris was minimal in all groups. Statistical analysis for the presence of smear layer showed no significant differences between the groups, whereas a significant difference was detected between the apical and middle thirds of each group.. Under the conditions of this study, root canal preparation with tapers 0.04, 0.06, or 0.08 did not affect canal cleanliness. Debris removal was almost complete for all tapers, whereas smear layer was not removed, especially from the apical part of the canals.

Topics: Dental Pulp Cavity; Dentin; Double-Blind Method; Edetic Acid; Humans; Incisor; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Tooth Apex

The aim of this study was to investigate the cleaning ability of a self-adjusting file (SAF) system regarding debris and smear layer removal using ethylenediaminetetraacetic acid (EDTA) or MTAD.. In total, 45 maxillary incisor teeth were randomly divided into 2 different irrigation groups of 20 canals each and a negative control group of 5 canals. The canals in each of the irrigation groups were irrigated using sodium hypochlorite (1.3%) as an initial irrigant during the first 2 minutes of operation, followed by 2 minutes continuous irrigation with either 17% EDTA or MTAD in a closed system. The negative control group was irrigated using 1.3% sodium hypochlorite. The roots were split longitudinally and subjected to scanning electron microscopy (SEM). The presence of debris and smear layer in the coronal, middle, and apical thirds of the canal was evaluated using a 5-grade scoring system with ×200 and ×2,000 magnification, respectively.. The SAF operation with 2-minute continuous irrigation using MTAD resulted in root canal walls that were free of smear layer in 85%, 70%, and 60% and of debris in 95%, 90%, and 95% of the coronal, middle, and apical thirds of the root canals, respectively. The SAF operation with continuous irrigation using EDTA resulted in root canal walls that were free of smear layer in 85%, 60%, and 50% and of debris in 95%, 90%, and 85% of the coronal, middle, and apical thirds of the root canals, respectively. Teeth in the negative control group were totally covered with debris. Evaluation by SEM showed no significant difference between the tested irrigants in removing the smear layer and debris among the different regions of the root canal. Both groups were significantly different from the negative control group.. When using the SAF, the protocols used in this study were effective for debridement for all regions of the root canal even for the apical thirds.

Topics: Adolescent; Chelating Agents; Citric Acid; Cone-Beam Computed Tomography; Dental Pulp Cavity; Dentin; Doxycycline; Edetic Acid; Humans; Hydrodynamics; Materials Testing; Microscopy, Electron, Scanning; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Time Factors; Tooth Apex; Vibration; Young Adult

To assess the push-out bond strength of two new calcium silicate-based endodontic sealers in the root canals of extracted teeth.. Thirty extracted single-rooted central incisors of similar sizes were selected randomly and distributed to three groups (n = 10). All canals were instrumented using ProTaper rotary instruments to achieve tapered canal walls. Irrigation was performed using 5 mL 2.5% NaOCl between each instrument, and the smear layer was removed using 5 mL 17% EDTA. The canals were filled with three different sealers using a cold lateral compaction technique: group 1: AH Plus + gutta-percha, group 2: I Root SP + gutta-percha and group 3: MTA Fillapex + gutta-percha. Three horizontal sections were prepared at a thickness of 1 mm ± 0.1 in the apical, middle and coronal parts of each root. The test specimens were subjected to the push-out test method using a Universal Test Machine (Instron, Canton, MA, USA) that carried 1-mm, 0.5-mm and 0.3-mm plungers for coronal, middle and apical specimens, respectively. The loading speed was 1 mm min(-1) . The push-out data were analysed by two-way analysis of variance (anova) and the post hoc Holm-Sidak test, with significance set at P < 0.05.. In the coronal specimens, there was no significant difference between the sealers. In the middle and apical segments, there was no significant difference between I Root SP and AH Plus groups. However, the I Root SP and AH Plus had significantly higher bond strength values than the MTA Fillapex (P < 0.05). In terms of root segments, the bond strengths in the middle specimens and the apical specimens were higher compared with the bond strengths in the coronal specimens (P < 0.05). There were no significant differences between the bond strengths in the middle and apical specimens.. MTA Fillapex had the lowest push-out bond values to root dentine compared with other sealers.

Topics: Aluminum Compounds; Calcium Compounds; Dental Bonding; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Drug Combinations; Epoxy Resins; Gutta-Percha; Humans; Humidity; Materials Testing; Oxides; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Silicates; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Temperature; Time Factors

This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.

Topics: Coloring Agents; Cuspid; Dental Bonding; Dental Leakage; Dental Pulp Cavity; Dentin; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Incisor; Lasers, Semiconductor; Materials Testing; Microscopy, Electron, Scanning; Radiation Dosage; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex; Water

To determine the efficacy of Sonicare CanalBrush irrigation for root canal cleaning.. Fifty human molar root canals were shaped with sequential NiTi rotary instruments up to size F3 (size 30, 0.09 taper; ProTaper system) and then enlarged apically with a Profile size 40, 0.04 taper. Five different irrigation protocols were tested (n = 10 canals per group) with 2 mL of distilled water (control, group I) or 2.5% NaOCl (control group II and test groups III, IV and V) between instrument size changes. Group III-IV received a final rinse with 17% EDTA for one min. This was extended by 30 s in group IV, whereas group V received this additional 30 s of 17% EDTA sonically dispersed with a Sonicare CanalBrush. For cleanliness evaluations, roots were split longitudinally, examined with scanning electron microscopy and scored according to Hülsmann et al. (1997) for debris and smear layer on the surface of the root canal wall. Walls were assessed at the coronal, middle and apical thirds. Data were analysed with the Kruskal-Wallis and Mann-Whitney tests.. Irrigation with 17% EDTA significantly reduced debris and smear layer scores (P < 0.05) compared to controls. The coronal and middle thirds had lower debris and smear layer scores than the apical third (P < 0.05). In all thirds, sonic agitation of the irrigant with a CanalBrush (group V) resulted in significantly cleaner canal walls compared to all other groups (P < 0.05).. Irrigation by agitation with the Sonicare CanalBrush improved root canal debridement in the coronal, middle and particularly the apical thirds of the root canal.

Topics: Chelating Agents; Dental Pulp Cavity; Dental Pulp Necrosis; Dentin; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Single-Blind Method; Smear Layer; Sodium Hypochlorite; Tooth Apex

The purpose of this in vitro study was to compare the sealing ability of the lateral condensation technique and the BeeFill system after canal preparation by the Mtwo rotary system. Forty extracted single-rooted teeth were prepared by using the Mtwo rotary system. The teeth were then divided into 2 experimental groups (n = 15 each) and 2 control groups (n = 5 each). The specimens in groups 1 and 2 were obturated using the lateral condensation technique and the BeeFill system, respectively. The teeth in the negative control group were also obturated with the lateral condensation technique, and the specimens in the positive control group were not root-filled. The specimens were then immersed in an aqueous solution of 2% China ink for 1 week, after which the roots were cleared and the linear extent of dye penetration was measured with a stereomicroscope by 2 endodontists. The data collected were then analyzed by using the 1-sample Kolmogorov-Smirnov test and independent t test, with a significance level of P < or = 0.05. Although the mean (+/- standard deviation) dye leakage in the BeeFill thermoplasticized injection group was less than that in the lateral condensation group (1.497 +/- 0.7 vs. 2.521 +/- 1.733), there was no significant difference between the experimental groups on the parametric independent t-test (P = 0.209).

Topics: Bismuth; Carbon; Coloring Agents; Dental Alloys; Dental Bonding; Dental Leakage; Dental Pulp Cavity; Epoxy Resins; Equipment Design; Gutta-Percha; Hot Temperature; Humans; Materials Testing; Nickel; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silver; Smear Layer; Sodium Hypochlorite; Titanium

The effect of sodium hypochlorite (NaOCl) gel along with EDTA on the removal of the smear layer has not been studied; therefore, the aim of the present study was to compare the efficacy of gel and solution forms of NaOCl in removal of the smear layer from root canal walls.. A total of 40 single-rooted teeth with minimum curvature (<5 degrees) were selected and divided into two experimental groups, each containing 15 teeth and one positive control group containing 10 teeth. The canals of all the teeth were prepared with rotary RaCe instruments up to #35. In the NaOCl solution group, the root canals were flushed with 2.5% NaOCl solution during instrumentation and in NaOCl gel group, the instruments were coated with gel form of NaOCl and used inside the root canals; then saline was used for root canal irrigation. Finally, 1 mL of 17% EDTA was used to rinse inside the root canals and remained in the root canals for 2 minutes in the both experimental groups; in the saline group, only saline was used for irrigation. The amount of the smear layer was quantified according to the Torabinejad method using a scanning electron microscope. Data were analyzed by the Kruskal-Wallis and Mann-Whitney tests. All the statistical analyses were set with a significance level of alpha = 0.05.. There were no significant differences between NaOCl gel and solution forms in the coronal, middle, and apical thirds of root canals. There were significant differences between NaOCl solution and saline groups in the three parts of root canal walls and between NaOCl gel and saline in the coronal, middle, and apical thirds.. The use of NaOCl gel can be as effective as NaOCl solution along with EDTA in smear layer removal in the three parts of root canal walls.

Topics: Chelating Agents; Dentin; Edetic Acid; Gels; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Solutions; Tooth Apex

A final flush with chelating agents and antiseptic irrigating solutions is needed to remove the smear layer. The improvement of these protocols is possible by using specific delivery and agitation techniques. This study examined the effect of different final irrigation regimens and methods of activation on smear layer removal in curved canals after root canal instrumentation.. Mesial root canals of 50 extracted mandibular molars were prepared using ProTaper rotary files (Dentsply Maillefer, Ballaigues, Switzerland) and 3% NaOCl. Teeth were then allocated to two control groups and four experimental groups (n = 10) for final irrigation as follows: no-activation group (final rinse with a 27-gauge needle and 17% EDTA/3% NaOCl), manual-dynamic activation group (final rinse 17% EDTA/3% NaOCl + gutta-percha agitation), automated-dynamic activation group (final rinse 17% EDTA/3% NaOCl + RinsEndo [Dürr Dental GmbH & Co KG, Bietigheim-Bissingen, Germany]), and sonic-activation group (final rinse 17% EDTA/3% NaOCl + Endoactivator [Advanced Endodontics, Santa Barbara, CA]). All mesial roots were split with a new approach to allow visualization of every third of the canal, particularly the apical third. The samples were prepared for scanning electron microscopic observation to assess the smear layer removal. Blind scoring was performed by two calibrated observers using a five-score scale. The differences in smear layer scores between the experimental groups were analyzed with the Kruskal-Wallis test and the Mann-Whitney U test. The level of significance was set at p = 0.05.. Very high levels of root canal cleanliness (< or = score 3) were found for each test group with activation. For the middle and apical third, the no-activation group was significantly less effective than the three other activation groups (p < 0.05). The manual-dynamic activation group (final rinse 17%EDTA/3%NaOCl + gutta-percha agitation) and the sonic-activation group (final rinse 17%EDTA/3%NaOCl + Endoactivator) showed significantly better smear layer removal (p < 0.05) in comparison with the other test groups in the apical third.. Root canal cleanliness benefits from solutions activation (especially sonic activation and manual-dynamic activation) in comparison with no activation during the final irrigation regimen.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Gutta-Percha; Humans; Microscopy, Electron, Scanning; Needles; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Therapeutic Irrigation; Time Factors; Tooth Apex

The aim of this study was to evaluate in vitro the apical sealing ability of cold lateral and system B root filling techniques using dye penetration. Eighty-six extracted single-rooted human teeth were prepared and randomly divided into two experimental groups to be obturated by cold lateral condensation (n = 33) and system B (n = 33). The remaining 20 teeth served as positive and negative controls. The roots were embedded for 72 h in methylene blue dye solution and sectioned transversely for dye penetration evaluation using stereomicroscope. The results of this study showed that cold lateral condensation leaked significantly more (P < 0.001) than system B technique.

Topics: Bismuth; Coloring Agents; Dental Alloys; Dental Bonding; Dental Leakage; Dental Restoration, Permanent; Edetic Acid; Epoxy Resins; Glass Ionomer Cements; Gutta-Percha; Hot Temperature; Humans; Hydrogen-Ion Concentration; Materials Testing; Methylene Blue; Nickel; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silver; Smear Layer; Sodium Hypochlorite; Temperature; Time Factors; Titanium; Tooth Apex

The aim of this study was to determine whether the debridement quality of the single-file F2 ProTaper instrumentation technique is comparable to a full conventional ProTaper sequence in both round and oval-shaped root canals.. Fifty-four recently extracted vital lower incisors were instrumented with either a full range of ProTaper Universal instruments in rotary motion (group 1) or with the single-file F2 ProTaper technique in reciprocating motion (group 2). Teeth were previously classified as round or oval-shaped by means of bidirectional radiographs, resulting in 24 round canals, 24 oval canals, and 12 controls. After instrumentation, the roots were demineralized, and the apical 3 mm was multi-sliced and processed for histologic examination. The percentage of residual pulp tissue (PRPT) was calculated with the aid of image analysis software. Univariate analysis of variance was used to verify the variables influencing PRPT.. Both canal shape and technique significantly influenced PRPT (P < .05). Oval-shaped canals displayed much more PRPT than round canals in both techniques (P < .05). The difference in PRPT between the techniques depended on the root canal shape, since a significant interaction between canal shape and technique was observed (P < .05). Group 1 displayed considerably less PRPT in oval canals than group 2 (P < .05), whereas in round canals no significant difference was found between the 2 techniques (P > .05).. The single-file F2 ProTaper technique displayed similar PRPT to the full range of ProTaper instruments in round canals. However, the debridement quality of the single-file F2 ProTaper technique was suboptimal in oval canals.

Topics: Adult; Anatomy, Cross-Sectional; Debridement; Dental Alloys; Dental Pulp; Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; Image Processing, Computer-Assisted; Incisor; Materials Testing; Nickel; Prospective Studies; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Software; Titanium

The aim of this study was to evaluate the concentration of calcium ions and smear layer removal by using root canal chelators according to flame atomic absorption spectrophotometry and scanning electron microscopy. Forty-two human maxillary central incisors were irrigated with 15% ethylenediaminetetraacetic acid (EDTA), 10% citric acid, 10% sodium citrate, apple vinegar, 5% acetic acid, 5% malic acid, and sodium hypochlorite. The concentration of calcium ions was measured by using flame atomic absorption spectrometry, and smear layer removal was determined by scanning electron microscopy. Mean +/- standard deviation, one-way analysis of variance, Tukey-Kramer, Kruskal-Wallis, Dunn, and kappa tests were used for statistical analysis. The use of 15% EDTA resulted in the greatest concentration of calcium ions followed by 10% citric acid; 15% EDTA and 10% citric acid were the most efficient solutions for removal of smear layer.

Topics: Acetic Acid; Calcium; Chelating Agents; Citrates; Citric Acid; Dental Alloys; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Incisor; Malates; Materials Testing; Microscopy, Electron, Scanning; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Citrate; Sodium Hypochlorite; Spectrophotometry, Atomic; Titanium

The aim of this study was to compare the effect of continuous, intermittent passive ultrasonic irrigation (PUI) and active scrubbing of irrigants with NaviTip FX (Ultradent, South Jordan, UT) in removing smear layer.. Forty single-rooted teeth were randomly divided into 5 test groups and subjected to final irrigation with 17% EDTA followed by 2.5% NaOCl for 1 minute each using different activation methods: no activation (control), brushing with NaviTip FX, continuous PUI with irrigant delivered at pulp chamber, continuous PUI with irrigant delivered through the ultrasonic unit, and intermittent PUI. Specimens were examined under scanning electron microscope, and the data were analyzed using Friedman 2-way analysis of variance, Kruskal-Wallis, and Mann-Whitney U tests.. NaviTip FX and intermittent PUI showed significantly lower smear score than other groups at the 3 mm level (P < .05).. Both brush and intermittent ultrasonic activation were effective in the removal of smear layer from the apical third.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Needles; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Syringes; Therapeutic Irrigation; Tooth Apex; Ultrasonic Therapy

This study compared the effectiveness of three obturation techniques for oval-shaped canals. Roots of 42 extracted teeth with oval canals were randomly divided into three groups: (1) ProTaper canal preparation and single cone obturation with matching gutta-percha point; (2) ProTaper preparation plus thermoplastic obturation (Thermafil); (3) Profile .06 taper and matching master cone with lateral condensation. Cross-sectional area of the canal space occupied by sealer cement and gutta-percha was measured in the coronal, middle, and apical thirds using an image analysis software. The percentage of the cross-sectional shape occupied by sealer cement was calculated. The Thermafil group was significantly lower than the single cone group or the lateral condensation group in the middle third (p<0.01) and lower than the single cone group in the coronal third (p<0.05). There were no significant differences between the single cone obturation group and the lateral condensation group in each level.

Topics: Azo Compounds; Coloring Agents; Dental Alloys; Dental Pulp Cavity; Dentin; Gutta-Percha; Humans; Naphthalenes; Nickel; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Titanium

The purpose of this study was to investigate smear layer removal and erosive capacity of different concentrations of EDTA on instrumented root canal walls.. Forty single-rooted teeth were instrumented using step-back technique and 2.5% NaOCl. The teeth were randomly divided into 4 groups, and final flushes were preformed with different concentrations of EDTA (15%, 10%, 5%, and 1%). All specimens were prepared for scanning electron microscope evaluation.. The results showed that there was no significant difference on the smear layer removal between different concentrations of EDTA (P = .1959). Only coronal versus apical thirds showed significant difference regarding presence of smear layer (P = .0176). Whereas 15%, 10%, and 5% EDTA solutions demonstrated similar erosion patterns on the root canal walls (P > .05), 1% EDTA caused restricted erosion (P < .0001). There was no significant difference among the regions in terms of erosion (P = .6399).. Lower concentrations of EDTA can be recommended for clinical usage to avoid excessive erosion of root canal dentin.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

This study investigated the effects of light penetration and removal of smear layer on the adhesive properties of self-etching adhesives to root canal dentin when using fiber posts.. Altogether 54 human incisors and premolars were decoronated, and the roots after preparing the post space were randomly assigned into six groups. Three groups were treated with a light-cured self-etching adhesive and the other three with a dual-cured self-etching adhesive. In a further sub-division, the first group was light-cured with an irradiation unit; the second was light-cured with the irradiation unit and a light-guiding attachment; and the third was light-cured with the irradiation unit and the attachment after removing smear layer by EDTA and NaOCl. Then, a glass-fiber post was luted into the post space by a dual-cured composite. After 24h, an hourglass-shaped specimen was trimmed and subjected to MTBS testing.. Using the light-guiding attachment and removing the smear layer reduced the incidence of pre-testing failure significantly from 57.1% to 19.0% (p<0.05) in the light-cured adhesive groups and from 68.3% to 3.2% (p<0.01) in the dual-cured adhesive groups. The MTBS in different locations within a post space were in the range from 8.9 to 17.5MPa in the light-cured group and from 11.2 to 17.2MPa in the dual-cured group.. Better light penetration in post spaces and removal of the smear layer are effective in improving the adhesive properties of self-etching adhesives to root canal dentin when using fiber posts.

Topics: Chelating Agents; Composite Resins; Dental Bonding; Dental Materials; Dental Prosthesis Design; Dental Pulp Cavity; Dental Restoration Failure; Dentin; Dentin-Bonding Agents; Edetic Acid; Glass; Humans; Light; Methacrylates; Post and Core Technique; Resin Cements; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Surface Properties; Tensile Strength; Time Factors

The effect of different post space irrigants on smear layer removal and dentin bond strength was evaluated. Sixty-six extracted sound maxillary central incisors were endodontically treated. After post space preparation, the teeth were assigned to three groups of 22 teeth each. The teeth of these three groups were irrigated for 1 min with 17% ethylenediaminetetracetic acid (EDTA) (group 1), 5.25% sodium hypochlorite (NaOCl) (group 2), or 0.9% sodium chloride (NaCl) (group 3). In each group, eight specimens were split longitudinally for smear layer evaluation, and the other fourteen specimens were filled with a self-etching adhesive system (Panavia F). Four of 14 specimens of each group were prepared for evaluation of the resin-dentin interdiffusion zone (RDIZ) and resin tags, and the other 10 specimens were serially sectioned for push-out test analysis. Smear layer removal and bond strength were affected by different post space irrigants. EDTA removed the smear layer extremely effectively and, as a result, improved the bond strength at each region (apical, middle, and coronal) of the roots. Resin tag formation and the RDIZ were also affected by different irrigants and in accordance with bond strength. Therefore, removal of the smear layer use a self-etching luting system plays an important role in bonding effectiveness.

Topics: Adult; Dental Bonding; Dental Cements; Dental Pulp Cavity; Dentin; Dentin-Bonding Agents; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Microscopy, Electron, Scanning; Middle Aged; Post and Core Technique; Resin Cements; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Stress, Mechanical; Surface Properties; Tooth Apex

This study evaluated the root canal wall morphology under scanning electron microscopy magnification after removal of 2 types of root canal fillings by using ultrasonic tips, nickel-titanium (NiTi) rotary instruments, and hand K-files.. Thirty-six extracted roots were filled by using AH Plus (DeTrey-Dentsply, Konstanz, Germany) as a sealer with Thermafil (Tulsa Dental Products, Tulsa, OK) (18 roots) or warm vertically condensed gutta-percha (18 roots). All fillings were removed up to the middle third by using Gates Glidden drills. The retreatment was completed by using K-files (group 1), M-Two NiTi rotary instruments (group 2), or ESI ultrasonic tips (group 3) in 12 roots each. Root canals were irrigated by using 10% ethylenediaminetetraacetic acid and 2.5% NaOCl. The samples were split longitudinally and observed by scanning electron microscopy (100-2000x). The presence of smear layer, filling debris, and the surface profile was evaluated in each picture. Kruskal-Wallis (analysis of variance) and Mann-Whitney tests were used to evaluate the differences between the obturation techniques, the 3 retreatment methods, and the canal thirds (P < .05).. Resin sealer tags were observed inside dentinal tubules. No statistical differences (P > .05) were found among the 3 retreatment methods. No statistical differences were observed between Thermafil and vertically compacted warm gutta-percha for each group or between the coronal third used as control, middle, and apical thirds.. All retreatment techniques showed similar performances in terms of smear layer morphology, debris, and surface profile. None of them completely removed filling debris from dentinal tubules of apical third.

Topics: Dental Alloys; Dental Pulp Cavity; Dentin; Edetic Acid; Epoxy Resins; Equipment Design; Gutta-Percha; Humans; Materials Testing; Microscopy, Electron, Scanning; Nickel; Retreatment; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Titanium; Tooth Apex; Treatment Outcome; Ultrasonic Therapy

The purpose of this study was to compare the effectiveness of Excite DSC (Ivoclar Vivadent, Schaan, Liechtenstein), a dentin bonding agent, with AH-26 (Dentsply, Detrey, Germany) as a root canal sealer by evaluating the penetration depth into the dentinal tubules and the tag density of the two compounds.. Forty-two extracted, single-rooted premolars were prepared and randomly obturated with either Excite DSC (n = 20) or AH-26 (n = 20). Two teeth were filled without sealer and used as controls. Randomly, one half of the specimens in each group (n = 10) was sectioned 3 days after obturation (short-term), and the other half (n = 10) was sectioned after 3 months (long-term). The specimens were sectioned perpendicular to the long axis in two regions and prepared for observation using scanning electron microscopy.. In the short-term evaluation, the mean penetration depth of AH-26 in the apical sections (520.48 micromol/L) was significantly higher than that of Excite DSC (0.00 micromol/L). In the long-term evaluation, AH-26 exhibited a significantly greater depth of penetration in both the apical (797.74 micromol/L) and middle sections (1162.11 micromol/L) than Excite DSC (321.43 micromol/L and 657.72 micromol/L, respectively).. AH-26 showed more dentinal tubule penetration depth than Excite DSC in both evaluation periods.

Topics: Acid Etching, Dental; Bismuth; Dental Bonding; Dental Pulp Cavity; Dentin; Dentin-Bonding Agents; Drug Combinations; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silver; Smear Layer; Sodium Hypochlorite; Surface Properties; Time Factors; Titanium; Tooth Apex

The aim of this study was to assess, by scanning electron microscopic (SEM) analysis, the ability of 17% EDTA and 7% maleic acid in the removal of the smear layer from the human root canal system.. Eighty single-rooted human anterior teeth were subjected to standardized root canal instrumentation (step-back technique) and were irrigated with 2.5% NaOCl after each instrument. Based on the final irrigating solution used, samples were divided randomly into three groups: (1) the EDTA group: 17% EDTA+ 2.5% NaOCl (n = 30), (2) the maleic acid group: 7% maleic acid + 2.5% NaOCl (n = 30), and (3) the control group: 0.9% saline (n = 20). After final irrigation, teeth were prepared for SEM analysis to evaluate the cleaning of the coronal, middle, and apical thirds of radicular dentin by determining the presence or absence of smear layer. The data was statistically analyzed using the Kruskall-Wallis test.. At the coronal and middle thirds, there was no significant difference between EDTA and maleic acid. Both were equally efficient in the removal of smear layer. In the apical third, maleic acid showed significantly better smear layer removing ability than EDTA.. Final irrigation with 7% maleic acid is more efficient than 17%EDTA in the removal of smear layer from the apical third of the root canal system, which is a crucial area for disinfection.

Topics: Dental Disinfectants; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Maleates; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex; Treatment Outcome

To examine the effects of various root canal irrigants on cervical dentine permeability by monitoring the diffusion of hydrogen peroxide (H(2)O(2)).. Sixty cervical dentine discs were prepared from human third molar teeth. After removal of enamel and cementum, the outer dentine surface was etched with 17% ethylenediamine tetraacetic acid (EDTA) for 1 min. The dentine discs were randomly assigned to five groups according to the irrigant used: A, saline solution; B, 2.5% sodium hypochlorite solution (NaOCl); C, 5% NaOCl; D, 17% EDTA and 2.5% NaOCl; E, 17% EDTA and 5% NaOCl. After irrigation on the inner dentine surface with the various solutions, the diffusion of 30% H(2)O(2) was evaluated through each disc using a plastic-split chamber. H(2)O(2) was applied to the inner-side chamber, while the outer-side chamber was filled with de-ionised water. After 30 min of application of H(2)O(2), the solution in the outer-side chamber was collected to determine the concentration of H(2)O(2) using a spectrophotometer.. The penetration of H(2)O(2) through dentine in group E was significantly highest, followed by groups D, C, B and A respectively (one-way anova, P < 0.05).. Among the irrigants used, 17% EDTA and 5% NaOCl had the greatest effect in increasing dentinal permeability to H(2)O(2).

Topics: Acid Etching, Dental; Chelating Agents; Dentin; Dentin Permeability; Diffusion; Diffusion Chambers, Culture; Edetic Acid; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Molar, Third; Root Canal Irrigants; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Spectrophotometry; Time Factors; Tooth Cervix; Young Adult

The objective of this study was to compare the effectiveness of F-files and ultrasonics to remove the smear layer from instrumented root canals when irrigated with sodium hypochlorite and EDTA. Sixty healthy human premolar teeth were instrumented with ProTaper file series to F3, and the canals were enlarged with Profiles 35/.06, 40/.06, and 45/.06. The canals were then instrumented with either the F-file or an ultrasonically activated #20 K-file with or without EDTA. The removal of smear layer was visualized using blind scanning electron microscopic micrographs. There appeared to be little difference between the F-file and the ultrasonically activated #20 K-file in removal of the smear layer with or without EDTA. The effect of ultrasonic activation appeared to be self-limiting with high-volume flushes of irrigant. It appears the F-file was not any more beneficial in removing smear layer. Conversely, smear layer removal appears to be mostly influenced by the introduction of an EDTA rinse.

Topics: Bicuspid; Chelating Agents; Dental Pulp Cavity; Dentin; Diamond; Disposable Equipment; Edetic Acid; Equipment Design; Humans; Microscopy, Electron, Scanning; Plastics; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy

This in vitro study evaluated, using a bacterial leakage model, whether intracanal medication with calcium hydroxide [Ca(OH)2]-based pastes prepared with different vehicles, has inhibitory effect on corono-apical leakage of bacteria. Forty instrumented human canines were dressed with Ca(OH)2 p.a. associated with: G1 = distilled water; G2 = polyethylene glycol (PG); G3 = PG + CMCP; and G4 = glycerin. Five teeth with intact crowns served as negative controls and 5 instrumented teeth without temporary dressing served as positive controls. All teeth were mounted in a 2-chamber apparatus and then exposed to human saliva for 63 days. Leakage was recorded when turbidity was observed in the lower chamber. Fifty percent of the samples of G1 and G2, 10% of G3 and 80% of G4 were fully contaminated after 9 weeks. Statistically significant differences were observed with paired comparisons G3 and G4 (p=0.0069), with G3 achieving better seal against bacterial leakage than G4.

Topics: Anti-Infective Agents, Local; Calcium Hydroxide; Camphor; Chlorophenols; Dental Leakage; Dental Pulp Cavity; Drug Carriers; Drug Combinations; Edetic Acid; Glycerol; Humans; Materials Testing; Pharmaceutical Vehicles; Polyethylene Glycols; Root Canal Irrigants; Root Canal Preparation; Saliva; Smear Layer; Sodium Hypochlorite; Solvents; Time Factors; Tooth Apex; Water

The purpose of this study was to compare the effect of 10 different endodontic irrigation and chelating treatments on dental pulp stem cell (DPSC) attachment to root canal surfaces. Thirty-eight extracted human nondiseased single-canal teeth were cleaned and shaped using ProTaper and ProFile rotary instrumentation (Tulsa Dentsply, Tulsa, OK). The irrigation treatments investigated were 6% sodium hypochlorite, 2% chlorhexidine gluconate, Aquatine Endodontic Cleanser, and Morinda citrifolia juice. The irrigation treatments were used in conjunction with EDTA or MTAD. The instrumented teeth were immediately placed in cell culture with confluent DPSCs for 1 week. The number of attached DPSCs appeared to be correlated with the cytotoxicity of the root canal irrigating solution (analysis of variance, p < 0.0001). The presence or absence of the smear layer had little influence on DPSC activity (chi-square, p > 0.05). The results suggest that biocompatible irrigants are needed to promote DPSC attachment to root canal dentin, which is essential to accomplish some regenerative endodontic therapies.

Topics: Biocompatible Materials; Cell Adhesion; Cell Line; Cell Shape; Chelating Agents; Chlorhexidine; Citric Acid; Dental Pulp; Dental Pulp Cavity; Doxycycline; Edetic Acid; Fibroblasts; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Morinda; Plant Extracts; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stem Cells; Tissue Culture Techniques

With a tube etching process, conical-ended optical fibers for middle infrared lasers that have lateral emissions can be produced, a feature of benefit for delivering laser energy onto the root canal walls. This study examined the ability of these improved laser tips when Er:YAG and Er,Cr:YSGG lasers were used in root canals in which thick smear layers had been created intentionally to provide a challenge for the laser system. Smear layer was assessed from scanning electron microscopy images with an objective digital method. Lasing improved the action of ethylene diamine tetraacetic acid with cetavlon (EDTAC) in removing smear layer. Conical fibers performed better than plain fibers, but there was no difference in performance between the 2 laser systems when matched for all other parameters. These results provide a "proof of concept" for lateral emitting fibers for endodontic procedures and illustrate the novel contribution of lasing to the action of EDTAC in dissolving smear layer.

Topics: Cetrimonium; Cetrimonium Compounds; Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Hydrogen Peroxide; Lasers, Solid-State; Materials Testing; Microscopy, Electron, Scanning; Optical Fibers; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

The aim of this in vitro study was to investigate the effect of the smear layer on apical microleakage in teeth obturated with mineral trioxide aggregate (MTA). Fifty single-rooted central maxillary teeth were used in this study. All teeth were instrumented to size 60 by using the step-back technique. The selected teeth were randomly divided into 2 groups (n = 20). In the first group (smear [+]), the teeth were irrigated with only NaOCl (5.25%). In the second group (smear [-]), the teeth were irrigated with ethylenediaminetetraacetic acid (EDTA) (17%) and NaOCl (5.25%) to remove the smear layer. The teeth were then filled with MTA. The computerized fluid filtration method was used for evaluation of apical microleakage. The quantitative apical leakage of each tooth was measured after 2, 30, and 180 days. Statistical analysis was done with the Mann-Whitney U and Wilcoxon signed ranks tests. At the end of this study there was no difference in 2 days between the groups, but removal of the smear layer caused significantly more apical microleakage than when the smear layer was left intact for 30 and 180 days (P < .005). Within the constraints of this study it can be concluded that the apical microleakage of MTA is less when the smear layer is present than when it is absent.

Topics: Aluminum Compounds; Calcium Compounds; Chelating Agents; Dental Bonding; Dental Leakage; Dentin; Drug Combinations; Edetic Acid; Glass Ionomer Cements; Humans; Materials Testing; Oxides; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silicates; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth Apex

This study measured hydroxyl ion diffusion through dentinal tubules into a bathing solution. Eighty single-canal, instrumented teeth were divided into 8 groups. Control groups 1 and 3 were irrigated with 10 mL 0.9% saline and 10 mL 6% sodium hypochlorite (NaOCl), respectively. Control groups 5 and 7 were irrigated with 3 mL and 1 mL 17% ethylenediaminetetraacetic acid (EDTA) and then 10 mL 6% NaOCl, respectively. Experimental groups 2, 4, 6, and 8 were irrigated as groups 1, 3, 5, and 7, followed by placement of calcium hydroxide (Ca(OH)2) into canals. Bathing solution pH was recorded for 30 days, a cementum defect was made, and then pH was recorded for another 30 days. With a paired difference test, average pH during steady state was statistically different and higher after the defect (P < .001). With Tukey multiple comparisons, post-defect pH for group 6 was found to be significantly greater (P < .01) than in other groups. This study indicated final canal irrigation with 3 mL 17% EDTA and 10 mL 6% NaOCl before Ca(OH)2 placement allowed the greatest hydroxyl ion diffusion to the root surface.

Topics: Analysis of Variance; Dental Cementum; Dentin; Edetic Acid; Humans; Hydrogen-Ion Concentration; Hydroxides; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

The purpose of this study was to compare the in vitro effectiveness of Morinda citrifolia juice (MCJ) with sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX) to remove the smear layer from the canal walls of endodontically instrumented teeth. Sixty extracted, single-rooted, mature, permanent, human premolar teeth with a single canal were inoculated with Enterococcus faecalis at 37 degrees C in a CO2 atmosphere for 30 days. The teeth were randomly allocated to 6 treatment groups; the pulp chamber was accessed, cleaned, and shaped by using ProTaper and ProFile rotary instrumentation to a size 35. During instrumentation the irrigation was provided by MCJ, NaOCl, CHX, MCJ/CHX, followed by a final flush of 17% ethylenediaminetetraacetic acid (EDTA). MCJ irrigation was also followed by a final flush of saline, and saline irrigation was also used as a negative control. The teeth were then processed for scanning electron microscopy, and the removal of smear layer was examined. Data were analyzed by chi2 statistical tests (P values) at a significance of 95%. The most effective removal of smear layer occurred with MCJ and NaOCl, both with a rinse of 17% EDTA. Both MCJ and NaOCl treatments were similarly effective with a rinse of 17% EDTA (P < .2471) to completely remove up to 80% of the smear layer from some aspects of the root canal. MCJ was more effective than CHX for removing smear layer (P < .0085) and saline as the negative control (P < .0001). The efficacy of MJC was similar to NaOCl in conjunction with EDTA as an intracanal irrigant. MJC appears to be the first fruit juice to be identified as a possible alternative to the use of NaOCl as an intracanal irrigant.

Topics: Bicuspid; Chi-Square Distribution; Chlorhexidine; Dental Pulp Cavity; Enterococcus faecalis; Humans; Morinda; Phytotherapy; Plant Extracts; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

This study compared the in vitro efficacy of Smear Clear (Sybron Endo, CA), a 17% ethylenediaminetetraacetic acid (EDTA) solution with surfactants, to 17% EDTA, with and without the use of ultrasonics, in removal of the smear layer. Seventy-five extracted teeth, randomly distributed into 5 test groups, were prepared by using ProFile rotary instruments (Dentsply Maillefer, Ballaigues, Switzerland) and subjected to different final irrigating regimes; group A, 1% sodium hypochlorite; group B, 17% EDTA; group C, 17% EDTA with ultrasonics; group D, Smear Clear; and group E, Smear Clear with ultrasonics. Samples were examined under the scanning electron microscope and scored for debris and smear layer removal. Statistical analysis showed that groups D and E did not perform significantly better than groups B and C. Group C performed significantly better than group B. Addition of surfactants to EDTA in Smear Clear did not result in better smear layer removal. The use of ultrasonics with 17% EDTA improved smear layer removal.

Topics: Chelating Agents; Dentin; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface-Active Agents; Tooth Apex; Ultrasonic Therapy

This in vitro study evaluated the ability of a warm gutta-percha obturation system Thermafil to fill lateral channels in presence/absence of smear layer. Forty single-rooted extracted human teeth were randomly divided into two groups for which different irrigation regimens were used: group A, 5 ml of 5% NaOCl + 2.5 ml of 3.6% H(2)O(2); group B, 5 ml of 5% NaOCl 5% + 2.5 ml of 17% ethylenediamine tetraacetic acid. A conventional crown-down preparation technique was employed. Obturation was performed using epoxy resin-based cement (AH Plus) and a warm gutta-percha plastic carrier system (Thermafil). Specimens were cleared in methyl salicylate and analyzed under a stereomicroscope to evaluate the number, length, and diameter of lateral channels. Lateral channels were identified in both groups at medium and apical thirds. Additional samples were prepared for scanning electron microscopy inspection to confirm the presence of smear layer in group A, and the absence of smear layer in group B. All lateral channels resulted filled in both groups. No statistically significant differences regarding number, length, and diameter were observed between the two groups. Smear layer did not prevent the sealing of lateral channels.

Topics: Chelating Agents; Dental Pulp Cavity; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Hydrogen Peroxide; Materials Testing; Microscopy, Electron, Scanning; Oxidants; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Tooth Apex

The present investigation recorded the 2-year clinical and radiographic outcome of one- and two visit endodontic treatment and studied the significance of the bacteriologic sampling results on the outcome. A randomization procedure allocated 53 teeth to one-visit treatment and 48 teeth to two-visit treatment. At the end of the study period, 32 teeth (65%) in the one-visit group and 30 teeth (75%) in the two-visit group were classified as healed. The statistical analysis of the healing results did not show any significant difference between the groups (p = 0.75). Forty-nine (80%) of the 61 teeth that were obturated after a negative micobiologic sample were classified as healed. Teeth sealed after positive samples healed in 44%. The present study gave evidence that similar healing results might be obtained through one- and two-visit antimicrobial treatment.

Topics: Calcium Hydroxide; Dental Pulp Cavity; Dental Pulp Necrosis; Female; Follow-Up Studies; Gutta-Percha; Humans; Hydrogen Peroxide; Male; Middle Aged; Oxidants; Periapical Periodontitis; Radiography; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Treatment Outcome; Wound Healing

The aim of this study was to evaluate the alterations of etched deciduous dentin when submitted to different time and concentrations of sodium hypochlorite (NaOCl), using scanning electron microscopy (SEM).. Forty deciduous anterior teeth were selected, cleaned and ground until expose a flat dentin area on the buccal surface. The specimens were randomly distributed into eight groups (n=5), according to dentin surface treatment (35% phosphoric acid etching for 7s--AE and/or NaOCl application), NaOCl solution concentration (5% or 10%), and time of application (0, 30, 60, and 120 s), as follows: G1: control (without AE and NaOCl); G2: only AE; G3, G4, and G5: AE+5% NaOCl for 30, 60, and 120 s, respectively; G6, G7, and G8: AE+10% NaOCl for 30, 60, and 120 s, respectively. All specimens were prepared for SEM analysis and the photomicrographs (three for each specimen) were classified according to a score as follow: 0: presence of smear layer (SL); 1: absence of SL+non-altered collagen fibrils; 2: absence of SL+collagen fibrils slightly altered; 3: absence of SL+collagen fibrils severely altered; and 4: absence of SL and absence of collagen fibrils. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (p<0.05).. All groups treated with NaOCl solution were significant different from G1 and G2, and showed alterations on the collagen fibrils network. Collagen complete removal was only observed when a 5% NaOCl solution was applied for 120 s and 10% NaOCl solution for 30, 60, and 120 s.. The NaOCl action produced significant changes in the etched deciduous dentin. The higher NaOCl concentration, the lower the time required to completely removing the collagen fibrils network in deciduous dentin.

Topics: Acid Etching, Dental; Collagen; Dentin; Dentin Solubility; Humans; Microscopy, Electron, Scanning; Oxidants; Phosphoric Acids; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth, Deciduous

To evaluate the effect of different root canal irrigating regimes on dentine penetration of Patent Blue dye.. Eighty extracted single-rooted human mandibular premolar teeth with narrow root canals were prepared using ProFile instruments. After each instrument, canals were irrigated with 1% sodium hypochlorite. Subsequently, teeth were randomly assigned to receive a 10 mL rinse of aqueous 17% (w/v) ethylenediaminetetraacetic acid or tap water for 2 or 10 min, followed by a final rinse with a 2% Patent Blue dye solution for 2 or 10 min (eight groups, n = 10 teeth per group). Teeth were then horizontally sectioned 3, 6 and 9 mm from the apex. Sections were digitally photographed and dye penetration was calculated as percentage of total dentine area using NIH Image J. Values were compared using one-way anova and Bonferroni correction with the alpha-type error set at <0.05. Representative tooth sections from all groups were further analysed using scanning electron microscopy.. No significant impact of irrigating protocols on dye penetration was found. Dye penetration was significantly (P < 0.001) greater in the coronal than middle, and in middle than in apical root thirds. When observed microscopically, irrigant penetration was independent of the presence of a smear layer, but was rather a function of tubular sclerosis.. Tubular sclerosis, a physiological phenomenon that starts in the third decade of life in the apical root region and advances coronally with age, was the main factor influencing penetrability of root dentine.

Topics: Analysis of Variance; Coloring Agents; Dentin; Edetic Acid; Humans; Root Canal Irrigants; Sclerosis; Smear Layer; Sodium Hypochlorite; Tooth Root

To compare the cleaning effectiveness of chamomile hydroalcoholic extract and tea tree oil to 2.5% sodium hypochlorite (NaOCl) solution as an intracanal irrigant for the removal of the smear layer.. Forty extracted, single-rooted, mature, permanent, human teeth were allocated at random into one of three experimental groups of ten teeth and two control groups of five teeth. For each tooth, the pulp chamber was accessed and the canal prepared using K-type files and Gates-Glidden burs, using a step-back technique; the apical stop was prepared to a size 30. Each canal was subsequently irrigated with one of the following solutions: distilled water (as a negative control), 2.5% NaOCl + 17% ethylenediamine tetraacetic acid (EDTA) (as a positive control), chamomile or tea tree oil or 2.5% NaOCl. Each tooth was split longitudinally and prepared for examination by scanning electron microscopy (SEM). The quantity of smear layer remaining on the three levels of each canal (coronal, middle and apical) was examined using magnifications of 2000 and 5000x. The data were analysed using nonparametric Kruskal-Wallis and Mann-Whitney U-tests.. The most effective removal of smear layer occurred with the use of NaOCl with a final rinse of 17% EDTA (negative control) followed by the use of a chamomile extract. Chamomile extract was found to be significantly more effective than distilled water and tea tree oil (P < 0.008). The use of a 2.5% NaOCl solution alone, without EDTA and that of tea tree oil, was found to have only minor effects. There was no statistical difference between distilled water, 2.5% NaOCl and tea tree oil.. The efficacy of chamomile to remove smear layer was superior to NaOCl alone but less than NaOCl combined with EDTA.

Topics: Dentin; Humans; Matricaria; Microscopy, Electron, Scanning; Plant Extracts; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Tea Tree Oil

Forty extracted maxillary incisors were decoronated, prepared in a crown-down fashion and randomly divided into two groups of 16 roots each. Remaining roots served as controls. Smear layer was removed with 17% EDTA followed by 5.25% NaOCl, the canals in group N were again rinsed with NaOCl before obturation with laterally compacted gutta-percha and Roth's 801 sealer. The roots in group E were rinsed with 95% ethyl alcohol instead of NaOCl for the final rinse. Leakage was determined using a fluid-flow model. Roots were cleared, split, and sealer penetration into the dentinal tubules was measured under light-microscopy. Group E demonstrated significantly greater sealer penetration (p = 0.002) and significantly less leakage (p = 0.040), than group N. Leakage could not be significantly correlated with sealer penetration (p = 0.725). Under the conditions of this study, we found that a final rinse with 95% ethyl alcohol increased sealer penetration and decreased leakage.

Topics: Dental Leakage; Dentin; Edetic Acid; Ethanol; Humans; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Zinc Oxide-Eugenol Cement

Potential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure MTAD was employed as the final irrigant after initial rinsing with NaOCl. This study examined the effect of NaOCl-MTAD interaction on the antimicrobial substantivity of MTAD in dentin. Dentin cores previously irrigated with either MTAD, or in conjunction with 1.3% NaOCl as an initial irrigant were placed on blood agar plates inoculated with Escherichia faecalis at 10(5) cfu/ml. Dentin cores irrigated with 1.3% NaOCl only, and autoclaved dentin disks were used as the respective positive and negative controls. After anaerobic incubation, the mean diameter of bacterial inhibition zones formed around the MTAD group was significantly larger than the NaOCl/MTAD group, which, in turn, was not significantly different from the NaOCl positive control. Oxidation of MTAD by NaOCl resulted in the partial loss of antimicrobial substantivity in a manner similar to the peroxidation of tetracycline by reactive oxygen species.

Topics: Anti-Bacterial Agents; Citric Acid; Collagen; Colony Count, Microbial; Dentin; Doxycycline; Drug Antagonism; Drug Combinations; Escherichia; Humans; Materials Testing; Microscopy, Electron, Scanning; Oxidation-Reduction; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

The goal of this study was to evaluate the cleaning ability of three acid irrigating solutions after hand and rotary instrumentation. Eighty human teeth were randomly divided in eight groups. Four groups were prepared with hand instrumentation and other four with ProTaper. The irrigating solutions were 15% citric acid plus 2.5% NaOCl; 15% EDTA plus 2.5% NaOCl; 5% orthophosphoric acid plus 2.5% NaOCl; and 2.5% NaOCl alone as control. Canal walls were observed with scanning electron microscopy, and photomicrographs were taken in apical, middle, and coronal thirds. A scoring system for debris and smear layer was used. Acid solutions with 2.5% NaOCl were effective in the elimination of smear layer or debris, and no significant differences were showed in smear layer removal between techniques. However, 2.5% NaOCl did not remove smear layer or debris, and no significant differences in debris were observed between manual and rotary techniques.

Topics: Acids; Adult; Chelating Agents; Citric Acid; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Middle Aged; Phosphoric Acids; Photomicrography; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

To evaluate coronal microleakage in filled root canals that received different biomechanical preparations and application of liquid adhesives over the root filling and the pulp chamber walls.. Root canals of 94 extracted canine teeth were filled after being biomechanically prepared with 1% sodium hypochlorite and divided into 3 groups. In 2 groups attempts were made to remove the smear layer with either 17% EDTA or Er:YAG laser irradiation (10 Hz, 250 mJ input, 112 mJ output). Liquid adhesive (Super Bonder and Single Bond adhesive) was applied and the teeth were immersed for 90 days in India ink.. Statistically significant differences were found for the different preparations, the use of liquid adhesives, and the different liquid adhesives. The use of Er:YAG laser, EDTA, and the liquid adhesive reduced coronal microleakage (P < .01).. Because of the risk of coronal microleakage, endodontically treated teeth should be restored as quickly as possible.

Topics: Aluminum Silicates; Bisphenol A-Glycidyl Methacrylate; Carbon; Chelating Agents; Coloring Agents; Cuspid; Dental Leakage; Dental Pulp Cavity; Dentin-Bonding Agents; Edetic Acid; Erbium; Humans; Laser Therapy; Methacrylates; Resin Cements; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Yttrium

This study histologically compared the in vivo debridement efficacy of hand/rotary canal preparation versus a hand/rotary/ultrasound technique in mesial root canals of vital mandibular molars. Group 1 consisted of 16 teeth prepared with a hand/rotary technique whereas group 2 consisted of 15 teeth prepared in similar fashion but followed by 1 min of ultrasonic irrigation, per canal, utilizing an ultrasonic needle in a MiniEndo unit. Five uninstrumented mandibular molars served as histologic controls. After extraction and histologic preparation, 0.5 microm cross-sections, taken every 0.2 mm from the 1- to 3-mm apical levels, were evaluated for percentage of tissue removal. Nonparametric analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for group 2 at all levels evaluated, except one. In conclusion, the 1 min use of the ultrasonic needle after hand/rotary instrumentation resulted in significantly cleaner canals and isthmuses in the mesial roots of mandibular molars.

Topics: Humans; Prospective Studies; Root Canal Irrigants; Root Canal Preparation; Single-Blind Method; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Ultrasonics

The purpose of this study was to compare levels of postoperative discomfort after cleaning and shaping of root canals using two protocols for removal of smear layer. Seventy-three consecutive patients requiring root canal treatment were included. At random, canals were cleaned and shaped with one of the following protocols. In group 1, 5.25% sodium hypochlorite was used as the root canal irrigant. The smear layer was removed by placing 17% EDTA in the canal(s) for 1 min followed by a 5-ml rinse with 5.25% NaOCl. In group 2, canals were irrigated with 1.3% NaOCl; the smear layer was removed by placing MTAD in the canal(s) for 5 min. Access cavities were closed with a sterile cotton pellet and Cavit. The patients recorded degree of discomfort at various time intervals after cleaning and shaping on a visual analogue scale for 1 wk. No significant statistical difference was found in the degree of discomfort between the two groups (p = 0.58).

Topics: Adult; Analysis of Variance; Chelating Agents; Chi-Square Distribution; Edetic Acid; Humans; Pain, Postoperative; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface-Active Agents; Surveys and Questionnaires; Toothache

To evaluate debris and smear layer scores after application of high-frequency electrical pulses produced by the Endox Endodontic System (Lysis Srl, Nova Milanese, Italy) on intact pulp tissue and organic and inorganic residues after endodontic instrumentation.. The study comprised 75 teeth planned for extraction. The teeth were randomly divided into two groups (60 teeth) and a control group (15 teeth): group 1 (30 teeth) was not subjected to instrumentation; group 2 (30 teeth) was instrumented by Hero Shaper instruments and apical stops were prepared to size 40. Each group was subdivided into subgroups A and B (15 teeth); two electrical pulses were applied to subgroups 1A and 2A (one in the apical third and one in the middle third, respectively, at 3 and 6 mm from the root apices); four electrical pulses were applied to subgroups 1B and 2B (two in the apical third, two in the middle third). The control group (15 teeth) was prepared with Hero Shapers and irrigated with 5 mL of EDTA (10%) and 5 mL of 5% NaOCl at 50 degrees C but not subjected to the electrical pulse treatment. Roots were split longitudinally and canal walls were examined at 80x, 200x, 750x, 1500x and 15,000x magnifications, using a scanning electron microscope. Smear layer and debris scores were recorded at the 3 and 6 mm levels using a five-step scoring scale and a 200-microm grid. Means were tested for significance using the one-way anova model and the Bonferroni post-hoc test. The differences between groups were considered to be statistically significant when P < 0.05.. The mean value for debris scores for the three groups varied from 1.80 (+/-0.77) to 4.50 (+/-0.68). The smear layer scores for group 2 and the control specimens varied from 2.00 (+/-0.91) to 2.33 (+/-0.99). A significant difference was found in mean debris scores at the 3 and 6 mm levels between the three groups (P < 0.001). The Bonferroni post-hoc test confirmed that the difference was due to group 1. In the two subgroups treated with four high-frequency pulses (1B and 2B) a substantial reduction in mean debris scores was found at the 3 and 6 mm level; subgroup 2B was practically free of organic residue. No significant differences for mean smear layer and debris scores were recorded between group 2 and the control group at the two levels; a significant difference was found only for mean smear layer scores at the 3 mm level between subgroup 2B and the control group (P < 0.05).. The Endox device used with four electrical pulses had optimal efficacy when used after mechanical instrumentation. Traditional canal shaping and cleaning was essential to ensure an effective use of high-frequency electrical pulses in eliminating residues of pulp tissue and inorganic debris.

Topics: Adult; Chelating Agents; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Electric Stimulation; Humans; Microscopy, Electron, Scanning; Middle Aged; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

The effect of the smear layer on the penetration depth of three different root canal sealers into the dentinal tubules was examined in 64 recently extracted single-rooted teeth. After chemomechanical preparation, the samples were randomly divided in two equal groups. The smear layer remained intact in group A, whereas complete removal of the smear layer was performed in group B. Two roots from each group were used as controls. Ten roots from each group were obturated with laterally condensed gutta-percha points and sealers AH Plus, Apexit, and Roth 811, respectively. Examination in scanning electron microscope revealed that the smear layer obstructed all the sealers from penetrating dentinal tubules. In contrast, smear layer removal allowed the penetration of all sealers to occur to a varying depth. These findings suggest that smear layer plays an important role in sealer penetration into the dentinal tubules, as well as in the potential clinical implications.

Topics: Analysis of Variance; Calcium Hydroxide; Chelating Agents; Dentin; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Zinc Oxide-Eugenol Cement

To evaluate surface cleanliness of root canal walls along post space after endodontic treatment using 2 different irrigant regimens, obturation techniques, and post space preparation for adhesive bonding.. Forty teeth, divided into 4 groups, were instrumented, using Ni-Ti rotary files, irrigated with NaOCl or NaOCl+EDTA and obturated with cold lateral condensation (CLC) or warm vertical condensation (WVC) of gutta-percha. After post space preparation, etching, and washing procedure, canal walls were observed using a scanning electron microscope (SEM). Amount of debris, smear layer, sealer/gutta-percha remnants, and visibility of open tubules were rated.. Higher amounts of rough debris, large sealer/gutta-percha remnants, thick smear layer, and no visibility of tubule orifices were recorded in all the groups at apical level of post space. At middle and coronal levels areas of clean dentin, alternating with areas covered by thin smear layer, smaller debris, gutta-percha remnants, and orifices of tubules partially or totally occluded by plugs were frequently observed.. After endodontic treatment, obturation, and post space preparation SEM analysis of canal walls along post space shows large areas (covered by smear layer, debris, and sealer/gutta-percha remnants) not available for adhesive bonding and resin cementation of fiber posts.

Topics: Acid Etching, Dental; Dental Pulp Cavity; Dentin; Edetic Acid; Gutta-Percha; Humans; Microscopy, Electron, Scanning; Post and Core Technique; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Surface Properties; Tooth Preparation; Tooth, Nonvital; Zinc Oxide-Eugenol Cement

Various organic acids, ultrasonic instruments, and lasers have been used to remove the smear layer from the surface of instrumented root canals. The purpose of this study was to investigate the effect of a mixture of a tetracycline isomer, an acid, and a detergent (MTAD) as a final rinse on the surface of instrumented root canals. Forty-eight extracted maxillary and mandibular single-rooted human teeth were prepared by using a combination of passive step-back and rotary 0.04 taper nickel-titanium files. Sterile distilled water or 5.25% sodium hypochlorite was used as intracanal irrigant. The canals were then treated with 5 ml of one of the following solutions as a final rinse: sterile distilled water, 5.25% sodium hypochlorite, 17% EDTA, or a new solution, MTAD. The presence or absence of smear layer and the amount of erosion on the surface of the root canal walls at the coronal, middle, and apical portion of each canal were examined under a scanning electron microscope. The results show that MTAD is an effective solution for the removal of the smear layer and does not significantly change the structure of the dentinal tubules when canals are irrigated with sodium hypochlorite and followed with a final rinse of MTAD.

Topics: Chelating Agents; Citric Acid; Dental Alloys; Dental Pulp Cavity; Dentin; Detergents; Doxycycline; Edetic Acid; Humans; Microscopy, Electron, Scanning; Nickel; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Titanium; Water

To evaluate the effectiveness of Glyde File Prep used in conjunction with sodium hypochlorite irrigation in the removal of smear layer produced during root canal instrumentation.. Thirty-nine extracted human teeth with single root canals were used. Access cavities were prepared and the teeth divided into three groups of 13 teeth each. Each group was treated by one of the three different regimes of irrigation and conditioning during root canal instrumentation. Group A: 0.5 mL of 1% NaOCl irrigation after each file size with an additional final irrigation of 10 mL 1% NaOCl; group B: 0.5 mL of 1% NaOCl irrigation after each file size with an additional final irrigation of 10 mL 17% EDTA; group C: Glyde File Prep coated on each instrumentation file used in conjunction with 0.5 mL 1% NaOCl irrigation after each file size and an additional final irrigation of 10 mL 1% NaOCl. The teeth were then longitudinally grooved and sectioned. Root canal cleanliness was evaluated with the aid of a Nikon light microscope (x40 and x100) and scanning electron microscope (x1000 and x3000). The debris scores obtained at three canal regions were compared statistically within the same group and among different groups using repeated measurements of analysis of variance (anova) with Bonferroni adjustments and anova with posthoc Tukey HSD, respectively.. The canals treated with EDTA and Glyde File Prep were significantly cleaner than those treated with NaOCl alone. The apical region of the root canals generally displayed more residual smear layer, but the difference was not significant.. Used in conjunction with NaOCl irrigation, Glyde File Prep was effective in removing smear layer produced during root canal instrumentation.

Topics: Analysis of Variance; Chelating Agents; Dental Pulp Cavity; Disinfectants; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex; Treatment Outcome

To evaluate in vitro the cleaning of root-canal walls after irrigation with different irrigants.. A total of 36 recently extracted human teeth were divided into four experimental groups according to the irrigating solution used: saline; 2% chlorhexidine; 2.5% sodium hypochlorite; and 2.5% sodium hypochlorite + EDTA. The cleaning of the apical, middle and coronal thirds of the root canals was evaluated by scanning electron microscope examination using a 4-point scoring system.. The best cleaning was obtained using 2.5% sodium hypochlorite and EDTA, followed by 2.5% sodium hypochlorite only (P < 0.05), whose cleaning was similar to chlorhexidine only in the cervical third. Cleaning by saline and 2% chlorhexidine was worse than the other two groups and was similar in all thirds. Better cleaning was found in the cervical and middle thirds for all groups with the worst results in the apical third.. The apical third of the root canals was not cleaned as well as the middle and coronal thirds. Cleaning by chlorhexidine and saline was inferior compared to the cleaning by sodium hypochlorite with and without EDTA.

Topics: Analysis of Variance; Anti-Infective Agents, Local; Chelating Agents; Chlorhexidine; Dental Pulp Cavity; Disinfectants; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Statistics, Nonparametric; Tooth Apex

The efficacy of various concentrations of citric acid at different pH values for the removal of the superficial smear layer from dentinal surfaces was examined through the use of scanning electron microscopy. Study design Fifty extracted teeth were irrigated with sodium hypochlorite (NaOCl) during instrumentation. Citric acid solutions at 50%, 25%, 10%, and 5% (wt/vol) concentrations were prepared. In addition, similar solutions of citric acid were buffered to pH 6. Citric acid solutions with original and buffered pH values were used as final rinses. Bidistilled water and NaOCl were used as controls. The data were analyzed by using nonparametric Kruskal-Wallis and Mann-Whitney U tests.. Lower concentrations with lower pH values removed smear layer more efficiently than the ones with higher pH values (P <.05), whereas no significant differences for higher concentrations were detected between low and high pH values. However, more destruction of peritubular dentin was observed at higher concentrations with low pH values.. Within the limits of this study, lower concentrations of citric acid with its original pH were found to be as effective as higher concentrations in the removal of superficial smear layer.

Topics: Buffers; Citric Acid; Dental Pulp Cavity; Dentin; Disinfectants; Humans; Hydrogen-Ion Concentration; Matched-Pair Analysis; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric

The purpose of this study was to evaluate canal cleanliness and smear layer removal after use of the Quantec-E irrigation system and to compare the system with traditional irrigation.. Forty anterior teeth were randomly assigned to 4 groups. Group A consisted of 15 teeth that were instrumented with .12, .10, .08, .06 and .04 tapered rotaries while simultaneously irrigated via the Quantec-E irrigation pump with 12 mL of 5.25% NaOCl, followed by 6 mL EDTA 17% in crown-down fashion, with a final flush with 4 mL 5.25% NaOCl. Group B consisted of 15 teeth that were instrumented with the same instrument sequence, and irrigated with the same volumes via traditional needle and syringe. Group C consisted of 5 teeth that were sectioned and examined under a scanning electron microscope (SEM) without any instrumentation and served as a negative control. Group D consisted of 5 teeth that were instrumented dry, without any irrigation, and served as a positive control. All teeth were sectioned buccolingually and examined with SEM at 700x magnification in the apical, middle, and coronal portions of the canals. Analysis of SEM images was performed by 5 independent examiners using a 4-point scoring system.. Irrigation with the Quantec-E irrigation pump resulted in cleaner canal walls, less debris, and more complete removal of the smear layer within the coronal one third, when compared with syringe irrigation. However, no difference was observed in the middle and apical one thirds of the root canal.. There was no significant difference between the 2 irrigation systems.

Topics: Dental Pulp Cavity; Dentin; Disinfectants; Equipment Design; Humans; Microscopy, Electron, Scanning; Needles; Observer Variation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Syringes; Therapeutic Irrigation

The purpose of this in vitro study was to test the effect of Ketac-Endo (KE) and AH 26 on resistance to root fracture and also to evaluate the effect of smear layer. Seventy-two human maxillary canine teeth were randomly divided into six groups (n = 12) and were prepared using six different methods: group 1: KE, without smear layer (smear -); group 2: KE, with smear layer (smear +); group 3: AH 26, smear (-); group 4: AH 26, smear (+); group 5 (negative control): nonprepared; group 6 (positive control): prepared but unfilled. After storing 1 week in 100% humidity at 37 degrees C, the coronal lingual walls and root canal spaces were lowered 2 mm below the buccal walls of the roots. The samples were placed into acrylic resin blocks so that 10 mm of buccal roots were exposed and were placed in a specially designed steel pad at an angle of 15 degrees to the long axis of the root. A slowly increasing force was applied at the junction of the buccal wall and root canal space until fracture occurred. The force required to fracture each tooth was recorded as kg and statistically analyzed using one-way analysis of variance and Duncan tests. The results indicated that instrumentation of the root canals significantly weakened the tooth structure to fracture (p < 0.05). The canals obturated with either sealer were significantly stronger than roots whose canals were instrumented but not obturated (p < 0.05), and there was no difference between the sealers. The presence or absence of the smear layer did not cause any significant effect on the root fracture resistance of the teeth (p > 0.05).

Topics: Analysis of Variance; Bismuth; Cuspid; Dental Pulp Cavity; Dental Stress Analysis; Drug Combinations; Epoxy Resins; Glass Ionomer Cements; Humans; Humidity; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silver; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Stress, Mechanical; Temperature; Time Factors; Titanium; Tooth Fractures; Tooth Root

This study was designed to compare different techniques for coronal dye leakage testing. One hundred and fifty extracted human anterior teeth were fully instrumented and randomly divided into two experimental groups of 60 teeth each, plus two groups of 15 teeth each for positive and negative controls. One group was rinsed with 5.25% NaOCl (smear layer intact), whereas the other group was flushed with 17% EDTA and 5.25% NaOCl (smear layer removed). Roots were obturated with gutta-percha using lateral condensation and AH Plus as root canal sealer. Each experimental group was divided into three subgroups of 20 teeth each for three methods of testing coronal dye leakage: passive dye penetration, penetration with vacuum applied, and fluid filtration methods. The teeth were left in 100% humidity at 37 degrees C for 5 days before being immersed in Indian ink for 2 days and cleared. The linear extent of dye penetration was measured. Mean depth of leakage for the groups with the smear layer intact was 2.5 +/- 1.0 mm for passive dye penetration, 6.7 +/- 2.8 mm for vacuum dye penetration, and 3.0 +/- 1.1 mm for fluid filtration dye penetration. In the group in which the smear layer was removed, the mean depths of leakage were: 3.2 +/- 2.1 mm for passive dye penetration, 5.8 +/- 2.8 mm for vacuum dye penetration, and 3.4 +/- 2.1 mm for fluid filtration. The vacuum method resulted in significantly (p < 0.05) more dye penetration than fluid filtration and passive dye penetration. The presence or absence of smear layer had no statistically significant effect (p > 0.05) on any of the leakage testing techniques.

Topics: Analysis of Variance; Anti-Infective Agents, Local; Carbon; Chelating Agents; Coloring Agents; Dental Bonding; Dental Leakage; Dentin; Edetic Acid; Epoxy Resins; Filtration; Gutta-Percha; Humans; Humidity; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite; Surface Properties; Temperature; Tooth Crown; Vacuum

The purpose of this study using a scanning electron microscope was to investigate the efficacy of four different irrigation techniques after canal preparation with Profile Ni-Ti rotary instruments. A modified technique for the use of Glyde File Prep is proposed. Forty anterior teeth were divided into four groups, instrumented, and irrigated as follows: physiological solution (group A), 2.5% sodium hypochlorite (group B), 2.5% sodium hypochlorite and Glyde File Prep (group C), and 2.5% sodium hypochlorite and Glyde File Prep applied at the end of the preparation with sterile paper points (group D). After scanning electron microscopic evaluation at three different levels, debris, smear layer, and dentinal tubules were scored. Groups A and B had significantly more smear layer and less open tubules on the canal walls compared with the group C and group D samples. Differences in the mean amount of debris between group A samples and other irrigation regimes were statistically significant.

Topics: Chelating Agents; Dental Alloys; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Humans; Microscopy, Electron, Scanning; Nickel; Paper; Root Canal Irrigants; Root Canal Preparation; Rotation; Single-Blind Method; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Titanium

To evaluate smear layer removal by different irrigating solutions under ultrasonic agitation.. Twenty recently extracted mandibular incisors with a single root canal were divided into four equal groups. Three groups were instrumented using the modified double-flared technique, the fourth remained unprepared. Each group was irrigated with either distilled water, 1.0% sodium hypochlorite alone or associated with 15% EDTAC between each file size. The final group was not instrumented but irrigated with 1.0% sodium hypochlorite and 15% EDTAC. A size 15 file energised by ultrasound was used with small amplitude filing movements against the canal walls in all groups. The teeth were split longitudinally and the roots measured to provide three sections of the same size (cervical, middle and apical). Samples were examined under the scanning electron microscope and assessed for the amount of smear layer by three independent and calibrated examiners. The scoring system ranged from 1 (no smear layer) to 4 (all areas covered by smear layer). Due to the non-parametric nature of the data, Friedman's test was used for statistical analysis.. Canal walls were covered with smear layer in the group irrigated with 1% sodium hypochlorite alone and the group irrigated with distilled water. Canals irrigated with 1.0% sodium hypochlorite associated with 15% EDTAC had less smear layer throughout the canal (P < 0.001). There were no statistical differences for the amount of smear layer found on the cervical, middle and apical thirds when each group was analysed separately.. Under ultrasonic agitation, sodium hypochlorite associated with EDTAC removed the smear layer from root canal walls, whereas irrigation with distilled water or 1.0% sodium hypochlorite alone did not remove smear layer.

Topics: Dental Pulp Cavity; Dentin; Drug Combinations; Edetic Acid; Humans; Incisor; Microscopy, Electron, Scanning; Observer Variation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Ultrasonic Therapy; Water

Glass-ionomer root canal sealer is commonly used because of its chemical bonding and favorable physical characteristics when bonding to dentin. This study was designed to determine the tensile bond strength of a glass-ionomer sealer (Ketac Endo, Espe, Seefeld, Germany) on root canal walls after pretreatment with different conditioners. Flat inner surfaces of root canal specimens were prepared. The specimens were divided into five groups of 10 teeth, and the groups were conditioned with one of the following smear layer removal solutions: 15% EDTA/NaOCl, 10% polyacrylic acid, 35% phosphoric acid, 6% citric acid, and 5.25% NaOCl as a control. Then the exposed root canal areas were coated with Ketac-Endo. Tensile bonding was measured using a universal testing machine until ultimate failure was obtained. The groups that were treated with phosphoric acid and citric acid showed significantly higher bond strengths than the groups that were treated with 15% EDTA and polyacrylic acid (p < 0.05). Bonding to dentin without smear layer removal (NaOCl group) was too low to be measured in the testing apparatus. Scanning electron microscopy confirmed that phosphoric and citric acids were more effective in removing smear layer than EDTA or polyacrylic acid. The result supported the view that pretreatment with phosphoric acid or citric acid should be used in association with glass-ionomer root canal sealer to achieve the most effective removal of the smear layer and to provide better adhesion.

Topics: Acid Etching, Dental; Acrylic Resins; Anti-Infective Agents, Local; Chelating Agents; Citric Acid; Dental Bonding; Dental Pulp Cavity; Dentin; Edetic Acid; Glass Ionomer Cements; Humans; Microscopy, Electron, Scanning; Phosphoric Acids; Root Canal Filling Materials; Smear Layer; Sodium Hypochlorite; Surface Properties; Tensile Strength

The aim of this study was to evaluate the potential of electrochemically activated (ECA) anolyte and catholyte solutions to clean root canals during conventional root canal preparation.. Twenty extracted single-rooted human mature permanent teeth were allocated randomly into four groups of five teeth. The pulp chambers were accessed and the canals prepared by hand with conventional stainless steel endodontic instruments using a double-flared technique. One or other of the following irrigants was used during preparation: distilled water, 3% NaOCl, anolyte neutral cathodic (ANC) (300 mg L-1 of active chlorine), and a combination of anolyte neutral cathodic (ANC) (300 mg L-1 of active chlorine) and catholyte. The teeth were split longitudinally and the canal walls examined for debris and smear layer by scanning electron microscopy. SEM photomicrographs were taken separately in the coronal, middle and apical parts of canal at magnification of x800 to evaluate the debridement of extracellular matrix and at a magnification of x2500 to evaluate the presence of smear layer.. Irrigation with distilled water did not remove debris in the apical part of canals and left a continuous and firm smear layer overlying compressed low-mineralized predentine. All chemically active irrigants demonstrated improved cleaning potential compared to distilled water. The quality of loose debris elimination was similar for NaOCl and the anolyte ANC solution. The combination of anolyte ANC and catholyte resulted in improved cleaning, particularly in the apical third of canals. The evaluation of smear layer demonstrated that none of the irrigants were effective in its total removal; however, chemically active irrigants affected its surface and thickness. Compared to NaOCl, the ECA solutions left a thinner smear layer with a smoother and more even surface. NaOCl enhanced the opening of tubules predominantly in the coronal and middle thirds of canals, whereas combination of ANC and catholyte resulted in more numerous open dentine tubules throughout the whole length of canals.. Irrigation with electrochemically activated solutions cleaned root canal walls and may be an alternative to NaOCl in conventional root canal treatment. Further investigation of ECA solutions for root canal irrigation is warranted.

Topics: Chlorine; Debridement; Dental Pulp Cavity; Dentin; Disinfectants; Electrochemistry; Extracellular Matrix; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Oxidants; Oxidation-Reduction; Pilot Projects; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stainless Steel; Water

To evaluate in vitro the dentin morphology in root canals in terms of tubule orientation, density and increase in surface area after etching.. Thirty anterior teeth were divided in 3 groups at random: the samples of Group 1 were used to study tubular morphology in SEM. Groups 2 and 3 samples were etched with 32% phosphoric acid. The teeth in Group 2 were examined by SEM without further treatment. The samples in Group 3 were treated with a bonding system and fiber posts were luted into the canal. These teeth were then processed for evaluation of hybrid layer formation and resin tags in dentin tubules. The observations were made according to location in the root dentin, tubule density was estimated, and the increase in area available for bonding after etching was calculated.. The observations revealed variability in tubule density and orientation within different areas of any one sample. Statistically significant differences in the density of tubules were found depending on location. The dentin surface area available for bonding increased by 202% after etching in the cervical third, 156% in the middle third, and 113% in the apical third of the root dentin. Group 3 samples showed that the thickness of the hybrid layer depended on the density of tubules. In the sectors with a low density of tubules, the hybrid layer was significantly thinner than in areas with a higher density of tubules. The increase in dentin surface area might be responsible for the enhanced bond strength after acid etching, but not all areas exhibited equal responses to etching.

Topics: Acid Etching, Dental; Analysis of Variance; Boron Compounds; Dental Bonding; Dental Pulp Cavity; Dentin; Dentin-Bonding Agents; Gutta-Percha; Humans; Methacrylates; Methylmethacrylates; Microscopy, Electron, Scanning; Phosphoric Acids; Post and Core Technique; Resin Cements; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Surface Properties; Tooth Apex; Tooth Cervix; Tooth Root

To evaluate whether the hybrid layer significantly contributes to the seal of adhesive Class V restorations placed in vivo and to the bond strength obtained in vitro.. 20 periodontally severely compromised anterior teeth were selected for the leakage study. In each tooth, one round 3 mm wide V-shaped cavity with a maximum depth of 2 mm was prepared on the labial surface crossing the cementum-enamel junction. The sample teeth were randomly divided into two groups of ten samples each: in Group 1, Scotchbond Multi-Purpose Plus was applied in combination with Z-100 following the manufacturer's instructions. In Group 2 the bonding procedure was the same as in Group 1, except that after the phosphoric acid treatment, the cavities were treated with 5% NaOCl for 2 min. Following a period of clinical service of 60-90 days, the teeth were extracted and processed for the leakage test.. At the enamel site, 30% of the samples of Group 1 and 70% of the samples of Group 2 showed dye penetration. At the dentin site, 50% of the samples of Group 1 showed leakage, while all the samples of Group 2 were severely infiltrated. Statistically significant differences between the groups both for the enamel sites (P < 0.05) and for dentin-cementum sites (P < 0.001) were found. Bond strength tests were performed on 2 mm thick dentin slides of tapered Class I cavities (n = 10 in each group). The mean bond strength value obtained from cavities treated without NaOCl was 15.23 (+/-1.40) MPa and with NaOCl treatment 20.52 (+/-1.70) MPa. Statistical analysis showed significant differences (P < 0.05) between the two groups. No hybrid layer was detected on the NaOCl-treated samples by scanning electron microscopy.

Topics: Acid Etching, Dental; Analysis of Variance; Coloring Agents; Composite Resins; Dental Bonding; Dental Cavity Preparation; Dental Cementum; Dental Enamel; Dental Leakage; Dental Restoration, Permanent; Dentin; Dentin-Bonding Agents; Double-Blind Method; Follow-Up Studies; Humans; Methylene Blue; Microscopy, Electron, Scanning; Middle Aged; Oxidants; Phosphoric Acids; Resin Cements; Silicon Dioxide; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Stress, Mechanical; Surface Properties; Zirconium

To evaluate the capacity of canal wall smear layer removal, precipitation caused by irrigant interaction, antibacterial activity and cytotoxicity of three 2-in-1 root canal irrigating solutions.. Forty single-rooted teeth were mechanically instrumented and irrigated with QMix, SmearOFF, Irritrol or 0.9% saline. Each tooth was evaluated for smear layer removal using scanning electron microscopy. Precipitation after interaction of the irrigating solutions with sodium hypochlorite (NaOCl) was evaluated with. There was no significant difference between QMix and SmearOFF in eliminating smear layers from the coronal-third and middle-third of the canal spaces. In the apical-third, SmearOFF removed smear layers effectively. Irritrol incompletely removed smear layers from all the canal-thirds. When mixed with NaOCl, precipitation was evident only with Irritrol. QMix demonstrated a higher E. faecalis cell death percentage and a smaller biovolume. SmearOFF exhibited a larger decrease in biovolume compared with Irritrol, although Irritrol had a higher death percentage. Irritrol was more cytotoxic than the other irrigants on a short-term interval. In terms of long-term cytotoxicity, both Irritrol and QMix were cytotoxic.. QMix and SmearOFF performed better in smear layer removal and antimicrobial activity. QMix and Irritrol were cytotoxic when compared to SmearOFF. Irritrol was associated with precipitation after interacting with NaOCl.. Evaluation of the smear layer removal capability, antibacterial activity and cytotoxicity of 2-in-1 root canal irrigants is necessary to ensure that they are safe to use during root canal treatment.

Topics: Anti-Bacterial Agents; Calcium; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

In this study, it was aimed to evaluate the smear and debris removal efficiency of laser and ultrasonic irrigation activation methods in traditional and conservative endodontic access cavity preparations. 60 freshly extracted human mandibular molar teeth were randomly divided into 2 groups according to the access cavity preparation (n = 30): Traditional endodontic access cavities (TEC) and Conservative endodontic access cavity (CEC). After the access cavity preparation, the mesiobuccal root canals were prepared to 35/0.4 with the VDW Rotate file system. Teeth with completed root canal preparation were randomly divided into 3 subgroups according to the final irrigation activation protocol (n = 30): Conventional needle irrigation, passive ultrasonic activation and laser activation. The crowns of the teeth were removed and the mesiobuccal roots were divided longitudinally into two halves, mesial and distal. Samples were scanned with scanning electron microscopy. Photomicrographs in the coronal, middle, and apical thirds of each specimen were taken at a magnification of 200 for debris and 1000 for evaluation of the smear layer. Data were analysed using the three-way Robust Anova test and Bonferroni test.The effect of access cavity design on remaining smear (p = 0.057) and debris (p = 0.5) was not statistically significant. The effect of the interaction of access cavity and irrigation activation on the remaining smear and debris was not statistically significant (p = 0.556, p = 0.333). Significantly fewer smears were detected in the laser activation group than in the ultrasonic activation and control groups. Conservative access cavities did not differ from conventional access cavities in terms of debris and smear.

Topics: Dental Pulp Cavity; Humans; Lasers; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

This study aimed to compare the effectiveness of ultrasound and acoustic and laser cleaning of curved root canals.. A total of 92 molars with independent root canals with a curvature of 20°-40° were prepared and standardized at 04 25# and stained with gentian violet solution for 72 h. Among them, 52 were randomly divi-ded into four groups for final rinsing (. In the upper part, the mean depth of infiltration was not significantly different between the experimental and control groups (. The PUI and PIPS methods facilitate the penetration of irrigation solution into the dentin canal in curved root canals, especially in the apical segment. The PIPS technique is effective in removing the smear layer in curved root canals.

Topics: Dental Pulp Cavity; Double-Blind Method; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

:This study compared the effectiveness of three irrigation methods in removing smear layer and debris in the presence of the fractured instrument. The three compared irrigation methods were conventional syringe irrigation, passive ultrasonic irrigation, and SWEEPS (Shock wave enhanced emission photoacoustic streaming) irrigation.. Sixty-three permanent mandibular molars with moderate curvature were included in this experimental study. Mesiobuccal root canals were prepared with Race files (FKG Dentaire. Switzerland) up to #25, 4%. A #30, 6% Race file was used to simulate file fracture 3 mm short of working length. The prepared samples, randomly divided into three groups, and final irrigation was separately done in each group. Group 1 conventional syringe irrigation (CSI) as the control group, Group 2 passive ultrasonic irrigation (PUI), and Group 3 Shock wave enhanced emission photoacoustic streaming or SWEEPS Irrigation (SI). Smear layer and debris removal beyond separated file scored with scanning electron microscope(SEM) images. Data were analyzed using the nonparametric tests to compare the smear layer and debris scores.. SWEEPS and passive ultrasonic irrigation significantly removed smear layer and debris, better than conventional syringe irrigation (p<0.001). The smear layer and debris removal efficiency between passive ultrasonic Irrigation and SWEEPS were not significantly different (p = 0.629).. In the face of the irretrievably broken instrument in the root canal, passive ultrasonic irrigation and the SWEEPS method can enhance smear layer and debris removal compared to conventional syringe irrigation.

Topics: Dental Pulp Cavity; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

To assess the effects of different peracetic acid (PAA) formulations on smear layer (SL) removal, dentine erosion, cytotoxicity, and antibiofilm activity.. SL removal and dentine erosion were assessed using 90 premolars, distributed into six groups, according to final irrigation: PAA formulations (1% Sigma, 1% Bacterend OX, 1% Arposept, and 0.09-0.15% Anioxyde), 17% ethylenediaminetetraacetic acid (EDTA), and water (control). Cytotoxicity was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red assays. Antibacterial and antibiofilm effectiveness was evaluated against Enterococcus faecalis. For cytotoxicity and antibiofilm activity assessment, the 2.5% NaOCl was also included.. EDTA, Sigma, and Bacterend OX removed more SL than Arposept, Anioxyde, and water (p<0.05). EDTA caused more severe dentine erosion than Sigma and Bacterend OX (p<0.05). Sigma and Bacterend OX had higher cytotoxicity than the other solutions (p<0.05). NaOCl, Bacterend OX, Sigma, and Anioxyde significantly reduced E. faecalis colony-forming units (CFU) (p<0.05). The 2.5% NaOCl solution promoted greater biofilm biomass reduction (p<0.05) than the other solutions. All PAA formulations promoted greater biomass reduction than 17% EDTA (p<0.05).. Although Sigma and Bacterend OX had higher cytotoxicity, they had a SL removal capability similar to that of EDTA, were as effective as NaOCl against E. faecalis biofilm, and promoted less dentine erosion than EDTA. Arposept and Anioxyde failed to remove the SL, had lower cytotoxicity, and showed less bacterial activity than NaOCl.

Topics: Biofilms; Dentin; Humans; Peracetic Acid; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

This study evaluated the effect of irrigation protocols using 95% ethanol (ET) or 1% peracetic acid (PA) prior the use of 2% chlorhexidine (CHX) compared to distilled water (DW) on the chemical smear layer (CSL) formation and incidence of open dentin tubules at the apical, medium, and cervical third of the post-space dentin. Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) images were used. Forty bovine roots were endodontically treated. After, post-space preparation was performed and the roots were randomized in four groups (n = 10) according to the irrigation protocol: DW, CHX, CHX-ET and CHX-PA. The chemical composition of CSL and the incidence of open dentin tubules at the post-space thirds were evaluated by EDS (500× magnification) and SEM (2000× magnification) images, respectively. Data from chemical composition of CSL were descriptively analyzed, while the incidence of open dentin tubules was evaluated by scores and submitted to Kruskal-Wallis and Dunn test (p = .05). Cl, Bi, and Si were the chemical elements most found over the dentin after the irrigation with CHX and CHX-ET. Moreover, CHX and CHX-ET showed the highest incidence of CSL (p < .05), but without difference between them (p > .05), regardless of the post-space third. DW and CHX-PA showed similar incidence of CSL (p > .05). No difference on the incidence of open dentin tubules was found for any irrigation protocol and post-space third (p > .05). The use of 1% PA prior the post-space irrigation with CHX decrease the incidence of CSL. RESEARCH HIGHLIGHTS: The post-space irrigation with chlorhexidine results in the formation of chemical smear layer. Ethanol is not capable to remove the chemical smear layer. Peracetic acid is more effective to remove the chemical smear layer.

Topics: Animals; Cattle; Chlorhexidine; Dental Pulp Cavity; Dentin; Edetic Acid; Ethanol; Microscopy, Electron, Scanning; Peracetic Acid; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

The purpose of this study is to investigate the effects of different root canal irrigation protocols applied to the dentin and artificial aging procedures on the micro pushout bond strength (mPBS) between dentin and hybrid ceramic posts. Seventy-five single-rooted mandibular premolar teeth were divided into 5 groups (Gr1-5). 50 of the teeth were used for the mPBS tests (n = 10), whereas 25 were used for the smear layer examinations (n = 5). Post space were prepared and irrigated with different irrigation-protocols in each group. (Gr1:[SS], Gr2:[NaOCl] + SS, Gr3:[EDTA] + NaOCl + SS, Gr4:[MA] + NaOCl + SS, Gr5:[Ch] + NaOCl + SS). Post and core pattern were fabricated with pattern resin and a fiber post, after scanning, the posts were milled with Vita Enamic resin ceramic block, and cemented. After 7 days the roots were sliced at thicknesses of 1 mm; half of them were subjected to mPBS test, while the other half were tested after undergoing mechanical cycling for artificial aging. For data analysis, the Shapiro-Wilk test was utilized to test normal distributions, 3-way analysis of variance was used to compare mPBS, and Tukey's HSD test was conducted for multiple comparisons. SEM analysis was performed for examination of failure modes and smear layer removal. Different root canal irrigation protocols affected mPBS significantly. While Gr4 had the highest mPBS, Gr1 had the lowest. Regarding to different zones, the highest mPBS was in coronal zone, and the lowest one was in the apical zone. The aging procedure also led to a statistically-significant decrease in mPBS. Most frequent failure modes were cohesive failure in dentin and mixed failure. Irrigation with 7%MA (Gr4) showed better performance than 17% EDTA (Gr3) in smear layer removal, especially at the apical zone of the tooth. This is critical for the success of root canal treatment and increased the mPBS to a higher extent in all zones of the tooth.

Topics: Bicuspid; Dental Bonding; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Materials Testing; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The aim of the present. Mesial roots of 48 primary mandibular second molars were prepared with an R-motion 21 mm file (30/0.04) (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland), irrigated with 1% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA), and divided into four groups (. The activation of the irrigant significantly improved debris and smear layer removal (. During pediatric pulpectomy, the irrigation protocol must include activation of the irrigation solutions using either ultrasonic, sonic, or mechanical activation techniques to enhance the removal of debris and smear layer for a better prognosis.. During root canal treatment on primary teeth, the clinician must incorporate an activation technique in the irrigation protocol to enhance the removal of debris and smear layer and increase the success of the treatment.

Topics: Child; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Molar; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

To this day, the effects of sodium hypochlorite and chelating agents on the smear layer and on the dentine's surface, remain not fully examined. The study is aimed to analyze the dentine's surface treated with 40% citric acid and 5.25% sodium hypochlorite according to two irrigation protocols.. The study employed a computer-controlled Nikon Eclipse LV100 optical microscope. Ten roots split longitudinally with canals prepared mechanically using the MTwo system to a size of 40/04 were observed. The root halves were divided into two study groups, one half in each of the groups. According to two irrigation protocols, the dentine's surface was irrigated with 40% citric acid and 5.25% sodium hypochlorite, separated with water. Dentine surface was observed in a fixed place and photographed in 500 × magnification after each irrigation stage. The obtained images were then analyzed using computer software (NIS-Elements AR, GIMP-2.6, ImageJ 1.45s).. Various speed of removal of the smear layer and varied morphological changes of the dentine's surface were observed in both examined groups. Double irrigation of the dentine with citric acid for 30 s resulted in complete removal of the smear layer, and double irrigation for 60 s resulted in increased mean diameter of the dentine tubules (degradation of the dentine's surface).. Double alternating irrigation with citric acid and sodium hypochlorite for 30 s yielded satisfactory results, while double irrigation for 60 s resulted in increased mean diameter of the dentine tubules. A real time assessment of the dentine's surface changes after both tested solutions can improve understanding of the phenomena that occur during the irrigation and as a result it might help to improve clinical outcomes in root canal treatment.

Topics: Citric Acid; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Adhesively cemented fiber-reinforced composite posts are commonly used to reconstruct endodontically treated teeth. Adhesion to intraradicular dentin is complex, and close contact between the resin cements and the dentin is essential. The removal of the smear layer following post space preparation (secondary smear layer) can improve this integration. Different mechanical systems have been used to activate the irrigant inside the root canal. The purpose of this study was to compare, ex-vivo, the removal of the smear layer from the walls of the immediate post space preparation by the action of three mechanized instruments. Forty premolar specimens with a single root canal were selected, endodontically treated, and shaped for glass fiber post cementation with Peeso reamer #1 (Dentsply Sirona, Switzerland) and Macrolock finishing drill #3 (RTD, France). The specimens were randomly divided into 4 groups (n=10): Group C (control); Group PUI (passive ultrasonic irrigation); Group CEP (Rotoprox brush, Hager Werken, Germany) and Group XP (XP-endo Finisher, FKG Dentaire, Switzerland). Post space surfaces were cleaned with 3mL of distilled water; each specimen root split longitudinally to expose the root canals, and prepared for examination in a scanning electron microscope at magnification 350X. The results were analyzed using the Kruskal-Wallis and Friedman tests (p>0.05). RESULTS: Statistically significant differences (p<0.05) were found between Groups C and XP in all three root regions, but not between Groups C, CEP and PIU. Of these, Group CEP showed a better trend in the results of the coronary and middle thirds, without significant difference with Group XP. Although it was difficult to achieve a clean dentin surface after preparation for the fiberglass post, the XP-endo Finisher was the most efficient in removing secondary smear layer, followed by the Rotoprox conical brush.. La fijación adhesiva de postes de fibra es un procedimiento habitual en la rehabilitación de piezas tratadas endodónticamente. La adhesión a dentina radicular resulta compleja, y es fundamental el íntimo contacto entre el medio resinoso y el sustrato dentinario. La eliminación del barro dentinario posterior a la preparación del anclaje intrarradicular podría mejorar esta integración. Para lograr una adecuada limpieza, se han implementado diferentes sistemas mecánicos para la activación del irrigante en el interior del conducto radicular. El objetivo del presente trabajo fue comparar ex-vivo la remoción del barro dentinario de las paredes de la preparación inmediata para poste por acción de tres instrumentos mecanizados. Se utilizaron 40 premolares inferiores unirradiculares tratados endodónticamente y preparados para anclaje intrarradicular con fresa Largo #1 (Dentsply Sirona, Suiza) y fresa piloto del sistema Macrolock Azul (RTD, Francia). Las piezas fueron divididas aleatoriamente en grupos (n=10): GC (control); G PIU (irrigación pasiva ultrasónica); G CEP (cepillo Rotoprox cónico, Hager Werken, Alemania) y G XP (XP-endo Finisher, FKG Dentaire, Suiza). Las preparaciones fueron irrigadas con 3ml de agua destilada; las piezas fueron seccionadas longitudinalmente en sentido proximal, metalizadas y observadas al microscopio electrónico de barrido a 350X. Las imágenes fueron analizadas bajo categorización ordinal y mediante las pruebas de Kruskall - Wallis y Friedman, estableciendo un p>o,o5. Existió diferencia significativa (p<0,05) entre el grupo G C y G XP en todos los tercios radiculares, pero no entre G C, G CEP y G PIU. Entre estos grupos, el G CEP marcó una tendencia a mejores resultados en tercio coronario y medio sin diferencia significativa con el G XP. A pesar de la dificultad para lograr una superficie dentinaria limpia luego de preparaciones para poste, el XP- endo Finisher fue el más eficiente en la remoción del barro dentinario secundario, seguido por el cepillo cónico Rotoprox.

Topics: Bicuspid; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The aim of the study was to evaluate the changes in free available chlorine (FAC) when 6% sodium hypochlorite (NaOCl) is admixed with irrigants 17% ethylenediaminetetraacetic acid (EDTA), 2% chlorhexidine (CHX), and 0.2% chitosan in varying proportions of 90:10, 80:20, and 50:50.. The 25 mL aliquots of 6% NaOCl were admixed in varying proportions of 90:10, 80:20, and 50:50 with secondary irrigation solutions: (a) 17% EDTA, (b) 2% CHX, (c) 0.2% chitosan. Iodometric titration was done to evaluate the change in FAC.. Kruskal-Wallis and Mann-Whitney tests.. On titration, the mean FAC value of NaOCl at baseline was 1.99 g%. On mixing NaOCl with EDTA, the FAC decreased in all the three proportions and the values were 0.17 g%, 0.17 g%, and 0.06 g% at 90:10, 80:20, and 50:50 ratios, respectively. pH obtained was 9.55 at 50:50 ratio. On mixing NaOCl with CHX, FAC reduced and the values were 1.84 g%, 1.72 g%, and 0.27 g% at 90:10, 80:20, and 50:50 ratios, respectively. pH obtained was 10.87 at 50:50 ratio. On mixing NaOCl and chitosan, the FAC remained unaltered in all the three proportions and the values were 1.64 g%, 1.51 g%, and 1.63 g% at 90:10, 80:20, and 50:50 ratios, respectively. pH obtained was 11 at 50:50 ratio.. Combination of NaOCl and chitosan did not lead to a reduction in FAC and the pH of the solution remained unaltered, suggesting that tissue-dissolving property of NaOCl might be preserved.. The combination of chitosan with NaOCl is advantageous in two ways. Firstly, FAC remained unaltered and the pH of the solution was also maintained at 11.05 indicating that the tissue-dissolving property of NaOCl prevailed. Secondly, chitosan is known for its chelating property and is effective in smear layer removal. With further

Topics: Chitosan; Chlorine; Edetic Acid; Humans; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

To evaluate the efficacy of a stepwise intraoperative activation (SIA) of irrigants during and after the instrumentation compared with that of a conventional activation (CA) performed only after the instrumentation to remove smear layer and debris using different activation devices.. A total of 70 single-rooted teeth were divided into a control group (no activation, n = 10) and two different experimental groups according to the irrigant activation protocol used: group 1 (CA), in which sodium hypochlorite was activated only after the use of the last mechanical file, and group 2 (SIA), in which activation was performed during and after the instrumentation. The two groups were divided into 3 subgroups according to the activation device used (n = 10): passive ultrasonic irrigation (PUI, subgroup a), EndoActivator (EA, subgroup b), and EDDY (subgroup c). The roots were split longitudinally and observed using scanning electron microscopy (SEM) to evaluate the presence of debris and smear layer, and the results were statistically analyzed.. All activation protocols and devices were more effective than control group in removing smear layer and debris from all root canal thirds (P < 0.05), except for CA-EA (group 1b) in the apical third. In the apical third, SIA was found to be more effective than CA (P < 0.05) to remove smear layer and residual debris when PUI was used, to remove the smear layer when EA was used (P < 0.05), and to remove residual debris when EDDY was used (P < 0.05). PUI and EDDY removed statistically more smear layer and debris than EA in the apical third (P < 0.05).. The SIA technique improved the smear layer and debris removal from the apical third and debris removal from the coronal third, and PUI and EDDY were more effective than EA in the apical third.. The stepwise intraoperative activation (SIA) technique may increase smear layer and debris removal.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

To evaluate via scanning electron microscopy the amount of smear layer generated during the use of sonic and ultrasonic activation systems with standardized short-term intentional contacts with the canal walls.. Seventy single-root human teeth were randomly assigned to 2 control (n = 5 each): NC (negative control), PC (positive control) and four experimental groups (n = 15 each): NC (negative control), PC (positive control), G1 (passive ultrasonic irrigation with Irrisafe), G2 (ultrasonic irrigation with EndoUltra), G3 (sonic irrigation with Endoactivator), G4 (sonic irrigation with Eddy). Samples were instrumented with ProTaper Next®. An irrigation protocol with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) was followed for both PC and the experimental groups. Standardized intentional contacts were made in the mesial walls during 5 s at WL - 2 mm in all experimental groups. Two calibrated evaluators scored the smear layer generated with an ordinal scale by scanning electron microscopy. The weighted kappa coefficient (K. When the agitation file is in contact with dentine walls, Irrisafe® significantly generated the least amount of smear layer in the coronal third (p < 0.05). Both in the middle and apical third, activation with Irrisafe® also showed statistically significant better results than Eddy™ and EndoUltra®. Endoactivator® showed significant better results than EndoUltra® and Eddy™ in the apical third (p < 0.05).. Irrisafe generated the least amount of smear layer in the entire canal and similar to Endoactivator in the apical third when the agitation file is in contact with dentine walls.. The smear layer is generated during activation. It is common to apply irrigation protocols where after the removal of the smear layer using chelants, a final rinse and activation is carried out but there are no previous studies analyzing the possible creation of a new smear layer with this final activation.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To evaluate the antibacterial efficacy of HybenX, an endodontic irrigant against Enterococcus faecalis biofilm and determine its efficacy in removal of smear layer. Forty root canals were inoculated with E. faecalis for three weeks, divided into 4 groups and irrigated with: Group1: 5 ml 2.5% sodium hypochlorite; Group2: 5 ml 2% chlorhexidine gluconate; Group3: 5 ml HybenX; Group4: 5 ml distilled water (control). Dentin shavings were collected and plated on agar plates, followed by colony forming unit (CFU) determination. For smear layer removal examination, 30 single rooted teeth were instrumented and divided into 3 groups and treated with: GroupI: 5 ml of 17% EDTA; GroupII:5 ml of HybenX; and GroupIII: 5 ml of distilled water. Samples were then subjected to SEM examination. All irrigants showed a significant reduction in CFUs compared to the control group (P⟨ .001), but none compared to each other. Regarding smear layer removal in the apical third, EDTA removed smear layer more effectively than HybenX (P = .014). HybenX demonstrated good antimicrobial efficacy against E. faecalis biofilm and removed the smear layer effectively in coronal and middle third of the root canal system. HybenX can be considered as a promising irrigating agent in root canal treatment of infected teeth.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; Biofilms; Dental Pulp Cavity; Edetic Acid; Enterococcus faecalis; Humans; Microscopy, Electron, Scanning; Phenols; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The purpose of this study was to evaluate current trends in access cavity design and cleaning and shaping among endodontists. A survey was e-mailed to active members of the American Association of Endodontists. Data showed that most respondents used traditional (57%) or conservative (43%) access cavities; less than 1% reported using ultraconservative access cavities. A glide path was created by 93% of respondents; NaOCl was used as lubricant by 51% of respondents, while 28% used RC Prep, 9% used liquid EDTA, 7% used Glyde, and 2% did not use any lubricant. Most respondents used NaOCl at 5.25% or higher concentration. Smear layer was removed by 92% of endodontists. Apical gauging was mostly accomplished with hand files. Clinical preferences varied among surveyed endodontists and among different age groups. Currently, very few endodontists use ultraconservative access preparations. There was large variation among the respondents suggesting a possible need for quality guidelines.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Surveys and Questionnaires

To assess the free available chlorine concentration (FAC), organic tissue dissolution and smear layer removal capacity of sodium hypochlorite (NaOCl) alone and when mixtured with etidronate (HEDP) and tetrasodium EDTA (Na. Mixtures at 1 : 1 ratio of 5% NaOCl with distilled water (considered NaOCl alone), 18% HEDP or 10% Na. In this laboratory study, heating NaOCl alone or when mixed with HEDP improved its capacity to dissolve organic matter and remove the smear layer. However, the mixture with HEDP required frequent refreshment to retain these effects when heated. Due to the acceleration in the reaction between the irrigants, very rapid reductions in the free available chlorine in the mixtures with Na

Topics: Animals; Cattle; Dental Pulp Cavity; Dentin; Edetic Acid; Etidronic Acid; Hot Temperature; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To evaluate the effect of the photon-initiated photoacoustic streaming (PIPS) technique on irrigation performance with different instrumentation tapers in root canals regarding smear layer removal and subsequent sealer penetration.. One hundred twenty human mandibular molars were divided into three equal groups according to the apical preparation taper (25/4%, 25/6%, and 25/8%). Each group was divided into two equal subgroups, one received passive irrigation (PI) while the other received PIPS activation of 2.5% sodium hypochlorite and 17% EDTA. Half the samples were evaluated using electron microscope images to assess smear layer removal. The other half was obturated using gutta-percha and rhodamine B-labeled AH Plus sealer before being sectioned horizontally at different root levels (coronal, middle, and apical) to evaluate the percentage of sealer penetration using CLSM. Mann-Whitney U and Friedman tests were used to analyze smear layer scores, while sealer penetration data were analyzed using the three-way analysis of variance (ANOVA) and Tukey's post hoc test.. Statistical analysis showed significantly better smear layer removal and better sealer penetration after PIPS activation when corresponding root thirds were compared (P<0.001). Only exception was sealer penetration in the apical third with root canal preparation of 25/4% where the difference between the irrigation methods was statistically insignificant (P>0.05).. The use of PIPS activation in the final irrigation protocol enhanced smear layer removal and sealer penetration into dentinal tubules if the taper of the prepared canal was at least 6%.. Increasing apical preparation taper significantly enhances PIPS performance in terms of irrigation activation thus enhancing smear layer removal and subsequent sealer penetration in dentinal tubules.

Topics: Edetic Acid; Humans; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Irrigation of the pulp space is a mandatory step to get rid of all its organic and inorganic content. Activation of the irrigants play a key role in the era of minimally invasive endodontics. The aim of this study was to assess the effectiveness of different irrigants activation methods in removing the smear layer at 1, 3, 5 and 8 mm from the apex from conservatively shaped canals.. Eighty-five human mandibular premolars were selected. Specimens were shaped to TruShape 25/.06 and divided into 5 groups (1 control and 4 test groups) according to the final activation technique (EndoActivator, EA), Ultrasonic (EndoUltra, PUI) and Laser (PIPS and SWEEPS). EDTA (Ethylenediaminetetraacetic acid) followed by NaOCl (Sodium Hypochlorite) and again EDTA were activated for each test group. Specimens were then split longitudinally and observed by Field Emission Scanning Electron Microscopy (FESEM). Blinded evaluation of the presence of smear layer was performed at 1000X magnification, according to a 5-score index system. Comparison between groups were analysed statistically using the Kruskal-Wallis non-parametric analysis of variance. Bonferroni multiple comparison tests were used.. At 1 mm only PIPS and SWEEPS performed better than the control group. At 3, 5 and 8 mm from the apex, every activation technique showed statistically significant reduction of smear layer when compared to the control group. PIPS and SWEEPS obtained better cleanliness result compared to EA, while only PIPS was superior to PUI in terms of cleanliness.. PIPS and SWEEPS showed the best results in conservative canal preparations. Nowadays, contemporary rotary instruments allow fast and minimally invasive shaping of the endodontic space. In this scenario irrigants' activation may be regarded as a mandatory step to a favourable clinical outcome.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Lasers; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

To compare the effectiveness of smear layer and debris removal in the final rinse of curved canals of permanent molars using different commercially available irrigant activation devices.. The mesial roots of 74 extracted maxillary and mandibular molars were instrumented using the Mtwo nickel-titanium rotary system (VDW GmbH, Munich, Germany). They were then randomly assigned to one of three groups, varying in their final rinse protocol. Group 1 (n = 15) - conventional needle irrigation with 4% NaOCl; Group 2 (n = 19) - EndoActivator® (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA) with 4% NaOCl; Group 3 (n = 17) - XP-endo® Finisher (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) with 4% NaOCl. After the final rinse, all canals were flushed with 1 mL 15% EDTA for 60 s and then flushed with saline. The roots were split longitudinally and prepared for scanning electron microscope imaging. ImageJ for Windows was utilised to assess the images for smear layer removal, while two blinded investigators assessed debris presence in the middle and apical thirds using a 5-point scale.. There was no significant difference in smear layer and debris removal between treatment and control groups in the same canal zones. A significant difference was noted across different canal zones both within and across the groups.. There is no statistically significant difference in effectiveness between activated irrigation techniques and manual activation. Further investigations are required to evaluate all methods available and determine the most efficient technique to irrigate successfully.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

In vitro evaluation of cleanliness of root canal walls of primary molars after preparation with the Self-Adjusting-File and Mtwo-instruments and final irrigation with citric acid and sodium hypochlorite.. s Study Design: In 23 matched pairs, teeth were prepared either with SAF or with Mtwo NiTi-instruments, and final irrigation was performed with 2 mL citric acid and 4 mL NaOCl. Roots were split longitudinally, SEM-images were taken, and smear layer was evaluated by two blinded observers using a four-grade score. Statistical evaluation was performed with Mann-Whitney-U-Test and Wilcoxon Signed Rank Test (P<0.05).. No significant difference between SAF and Mtwo (P=0.9454) was observed. Overall removal of the smear layer was significantly better in the coronal part of the root canal than in the apical one (P=0.0004393). Mtwo showed no significant difference in cleanliness when comparing the coronal and apical part of the root canal (P=0.1089), whereas SAF cleaned the coronal part of the root canal significantly better than the apical part (P=0.00108).. None of the two instruments was superior concerning cleanliness in root canals of primary molars. Both show good cleaning ability when using an irrigation protocol with citric acid and sodium hypochlorite.

Topics: Dental Pulp Cavity; Humans; Microscopy, Electron, Scanning; Molar; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

This study aimed to evaluate the effect of optimized irrigation with photon-induced photoacoustic streaming (PIPS) activation of different irrigants (distilled water or ethylenediaminetetraacetic acid [EDTA]) on smear layer removal, dentin microhardness, attachment morphology, and survival of stem cells of the apical papilla (SCAP) in an organotypic root canal model.. A total of 144 standardized root segments were randomly allocated into 6 groups for irrigation: (i) NaOCl group, (ii) NaOCl + EDTA group, (iii) NaOCl + PIPS (distilled water) group, (iv) NaOCl + PIPS (EDTA) group, (v) NaOCl + EDTA + PIPS (distilled water) group, and (vi) NaOCl + EDTA + PIPS (EDTA) group. Each group was divided into four subgroups for assessment: (i) dentin cleanliness; (ii) dentin microhardness; (iii) cell attachment morphology; and (iv) viable SCAP quantification.. Compared with the control groups, the NaOCl + EDTA + PIPS (EDTA) group showed higher efficiency in smear layer removal and in increasing SCAP viability with more stretched cellular morphology. There were no statistically significant differences in either smear layer removal effect, dentin microhardness, attachment morphology, or survival of SCAP among the other groups when optimized with PIPS (distilled water or EDTA) (P > 0.05).. Our findings indicated that irrigation optimized with PIPS activation of EDTA for 40 seconds was conducive to smear layer removal without additional dentin microhardness decrease. Additionally, this irrigation created more cell-friendly dentin conditioning than other approaches, which was beneficial for the attachment and survival of SCAP. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Topics: Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stem Cells

The present study aimed at assessing the effectiveness of different intracanal irrigation devices on the removal of the smear layer.. The recently extracted 80 lower premolars having single canal were chosen for this. Irrigation with EndoVac system activation showed the presence of least smear layer (2.40 ± 0.32), followed next by EndoActivator (3.24 ± 0.46) and ultrasonic activation (4.96 ± 0.54) and conventional needle irrigation (5.20 ± 0.10). No statistically significant difference was found in the apical and coronal thirds of the root canal in removal of the smear layer on an intragroup comparison. However, a statistically significant (. This study demonstrated the EndoVac system group to be efficient in removal of the smear layer when compared to the EndoActivator system, ultrasonic activation, and conventional needle irrigation group.. The definitive objective of endodontic therapy is to transform the affected teeth to a healthy and functional state. The irrigants can reach the working length when delivered by an effective irrigation delivery system. This type of delivery system should deliver adequate volume of irrigants all the way up to the working length and have sufficient flow and be efficient at debridement of complete canal system.

Topics: Dental Pulp Cavity; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

The present study aimed to evaluate and compare the efficacy of 17% ethylenediaminetetraacetic acid (EDTA), 18% etidronic acid, 10% citric acid, and 7% maleic acid in the removal of smear layer at the apical third of the root canals.. Sixty single-rooted teeth were equally divided into four study groups (. A 7% maleic acid revealed better smear layer removal than all other three groups at apical third. A 10% citric acid was found to be more efficient than EDTA and etidronic acid. The intergroup comparison was performed using Mann-Whitney U test, and there was no significant difference between all the study groups, except maleic acid.. The present study compared the effect of various irrigants as an adjunct with 5.25% of sodium hypochlorite for root canal irrigation during and after instrumentation. The use of irrigants aids in the removal of the smear layer from the root canals, thereby increasing the success rate of endodontic therapy.. This study supports the hypothesis that a thorough use of root canal irrigants can efficiently remove the smear layer which is the key for successful root canal treatment. The present study helps in choosing an appropriate irrigant that can ensure complete root canal debridement from all thirds, especially from the apical third of the root canal. How to cite this article: Mankeliya S, Singhal RK, Gupta A,

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To identify chelators which when mixed with sodium hypochlorite (NaOCl) are stable, exhibiting minimal loss of free available chlorine (FAC) over 80 min and to further investigate potential mixtures by assessing FAC over 18 h and the capacity to remove smear layer.. Alkaline 0.5 mol L

Topics: Chelating Agents; Clodronic Acid; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

After the mechanical preparation of a root canal, the canal walls are covered with a smear layer. In order to deeply clean the dentinal tubules, removal of the smear layer is recommended. There is no consensus on the length of time of rinsing with chelating agents or irrigation with alternating chelating agents and sodium hypochlorite (NaOCl).. The aim of the study was to evaluate the effectiveness of smear layer removal using 4 irrigation protocols.. We prepared 42 straight root canals to size ISO40/04 and assigned them into 4 study groups (n = 10) and a control group (n = 2). The root canals were irrigated as follows: in the control group, 180 s with 5.25% NaOCl; in group 1, 60 s with 40% citric acid (CA) and 120 s with NaOCl; in group 2, 120 s with CA and 120 s with NaOCl; in group 3, 30 s CA, 30 s with NaOCl, 30 s CA and 120 s with NaOCl; and in group 4, 60 s with CA, 30 s with NaOCl, 60 s with CA, and 120 s with NaOCl. The roots were split longitudinally and the root canals were observed under ×200-500 magnification. The root canal walls were analyzed in areas 2 mm, 6 mm and 10 mm from the apex.. In the apical and medial sections, the best effects were achieved in groups 3 and 4. In coronal sections, no significant differences between experimental groups were found.. Within the limitations of this study, it can be concluded that irrigation with alternating NaOCl and CA was the most effective at smear layer removal, regardless of the irrigation time.

Topics: Chelating Agents; Dental Pulp Cavity; Humans; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To compare the cleanliness and erosion of root canal walls after the use of a new HEDP (1-hydroxyethane-1,1-diphosphonic acid) -based irrigant with that achieved by irrigation with sodium hypochlorite followed by EDTA.. Forty recently extracted single-rooted teeth were prepared with ProTaper Next files to size X3, using either HEDP-containing 3% sodium hypochlorite, throughout the procedure (n = 20), or 3% sodium hypochlorite followed by a final rinse with 17% EDTA (n = 20), which were both applied with a syringe and needle. Ten additional teeth were prepared and irrigated with saline and served as negative controls. The teeth were split longitudinally and subjected to SEM evaluation for the presence of a smear layer, debris, and erosion of the root canal wall. The Pearson chi-square test was used to compare the results, and the level of significance was set at p < 0.05.. In both groups, there were more cases with a smear layer in the apical third of the root canal than in the coronal third, but the groups did not differ from each other significantly (p = 0.545). The root canal walls in both groups were almost free of debris, showing no difference between the groups (p = 0.342). Moderate erosion of the root dentine was found in 10-26% of the cases in both groups, but severe erosion was detected in only one case in each of the groups, which did not differ significantly from each other (p = 0.606).. Within the limitations of the present study, the HEDP-based irrigation solution did not differ from 3% sodium hypochlorite followed by EDTA in terms of cleanliness or the incidence of erosion of the canal wall.. When used with syringe and needle irrigation, the new HEDP-based irrigant is convenient and safe but should not be expected to result in cleaner canal walls than 3% sodium hypochlorite followed by 17% EDTA.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Etidronic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

This study aimed to assess whether ultrasonic activation (UA) or the EasyClean (EC; BassiEndo, Belo Horizonte, BH, Brazil) or EDDY (ED; VDW, Munich, Germany) systems used to promote agitation of the irrigating solutions during the final irrigation step can lead to smear layer formation in the apical third of the root canal.. Thirteen premolars were instrumented with the Reciproc R40 file (VDW) and embedded in silicone, forming a closed irrigation/aspiration system. The teeth were cleaved, and 4 indentations were made on the inner buccal wall of the canal to standardize the observation sites. All the specimens were cleaned in an ultrasonic bath and evaluated under environmental scanning electron microscopy, thus constituting the control group. The same specimens were reassembled, submitted to final irrigation using UA or the ED or EC systems, and classified using a 4-level scoring system. The data were analyzed using the kappa, Pearson, and Kruskal-Wallis tests (P < .05).. Smear layer formation occurred in all of the experimental groups and at all apical levels. At 3 and 4 mm, all of the experimental groups had significantly higher levels of smear layer formation than the control group. At 2 mm, the level of smear layer formation in the UA group was significantly higher than that of the control group, and there were no significant differences among the EC, ED, and control groups. At 1 mm, there were no significant differences between the ED and control groups, and the levels of smear layer formation in the EC and UA groups were significantly higher than that of the control group. There were no significant differences between the ED and EC groups at any of the apical levels.. The smear layer formation occurred in all of the specimens submitted to final irrigation, irrespective of the technique used.

Topics: Brazil; Dental Pulp Cavity; Edetic Acid; Germany; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

In this study, we investigated the properties of nanobubble (NB) water and its effect on smear layer removal and strengthening the efficiency of disinfecting agents used in regenerative endodontic treatment.. NB water was generated in a NB Generator. The NB size, concentration, and pH were measured. Porcine teeth were enlarged to size 60 by using hand-files and irrigated with either NB water or 17% EDTA or received no further irrigation. The ability of irrigants to remove the smear layer was evaluated by using a scanning electron microscope (9 roots/group). Other samples (6 roots/group) were subjected to Vickers hardness test to determine the dentin microhardness. Autofluorescent tetracycline mixed with distilled water or NB water was placed inside the root canal space of porcine teeth, and the depth of medicament penetration into the dentinal tubules was visualized by using fluorescent stereomicroscope (5 roots/group). For the disinfection experiment, human roots were prepared, autoclaved, and inoculated with Enterococcus faecalis for 3 weeks. Canals were then disinfected by (1) standard needle irrigation (SNI) with 5.25% NaOCl, (2) 5.25% NaOCl with ultrasonication (US), (3) 5.25% NaOCl + XP finisher (XP), (4) SNI with 1.5% NaOCl, or (5) SNI with 1.5% NaOCl in NB water (5 roots/group). Teeth were split open and stained with LIVE/DEAD BackLight and visualized by using confocal laser scanning microscope (CLSM) at the coronal, middle, and apical thirds of the canal. The ratio of dead/total bacteria in the dentinal tubules at various depth levels (50, 100, and 150 μm) was calculated.. NB water was more effective in removing smear layer than 17% EDTA and could allow infiltration of tetracycline into the dentinal tubule more than 1 mm. NB water did not alter the dentin microhardness compared with 17% EDTA (P < .05). At 50-μm depth, CLSM analysis showed no statistically significant difference between 1.5% NaOCl in NB water and 5.25% NaOCl with or without irrigation activation at the coronal, middle, and apical root segments (P > .05), ie, these groups had stronger bacterial killing than 1.5% NaOCl (P < .05). At deeper levels (100 and 150 μm), higher concentrations of NaOCl were more effective than 1.5% NaOCl with or without NB water. No statistically significant difference was noted between 5.25% NaOCl with and without irrigation activation at most depth levels (P > .05).. NB water can allow smear layer removal and enhance tubular penetration of medicaments without changing dentin microhardness. In large canal models, NB water appears to improve the tubular disinfection capacity of lower concentration of NaOCl up to 50 μm. On the other hand, the use of irrigation activation (US or XP) did not provide any added disinfection into the dentinal tubules compared with SNI. These results suggest that NB water may be a promising adjunct to endodontic irrigants and medicaments.

Topics: Animals; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Regenerative Endodontics; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Swine

The aim of this study was to evaluate the effectiveness of SmearOFF solution on smear layer removal by using different irrigation activation techniques. One hundred and twenty mandibular premolars were decoronated, and instrumented with Reciproc up to size 50. Then, the specimens were divided into 6 groups according to the final irrigation activation technique: Group 1: SmearOFF + Conventional syringe irrigation (CSI); Group 2: SmearOFF + Sonic activation (SA); Group 3: SmearOFF + Passive ultrasonic activation (PUA); Group 4:17% EDTA + CSI; Group 5:17% EDTA + SA, and Group 6:17% EDTA + PUA. Teeth were split longitudinally, and specimens were observed under scanning electron microscope. Images were taken from the coronal, middle, and apical thirds of the teeth with 1,000× magnification and analyzed using ImageJ program to calculate total open dentinal tubule areas. Three-way ANOVA test was applied to reveal any significant differences among solutions, activation techniques and root thirds. There was no statistically significant difference among the groups in terms of irrigation solutions (p > .05). There was a statistically significant difference between PUA and CSI groups (p < .05). However, no significant difference was observed between PUA and SA, or between SA and CSI (p > .05). All experimental procedures were most effective in the middle region of the root, followed by cervical and apical thirds (p < .05). PUA showed higher efficacy in smear layer removal compared with CSI. SmearOFF and 17% EDTA showed similar results. The best results in removing smear layer were obtained in the middle region of the root.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The study was aimed to conduct a morphological assessment of the influence exerted by a certain method of activation of endodontic rinsing liquid on the root dentin structure and canal cleaning effectiveness in an ex vivo experiment. The study was performed on 20 single-rooted teeth removed due to complicated caries in people aged 25-44 years. A devised method of vacuum-jet irrigation was used to carry out the final antiseptic treatment and to activate a rinsing liquid in the group No. 1 (. Морфологическая оценка влияния способа активации ирригационного раствора на структуру дентина корня зуба и качество очистки корневого канала в процессе эндодонтического лечения в эксперименте. Исследование выполнено на 20 однокорневых зубах, удаленных по поводу осложненного кариеса у лиц в возрасте 25—44 лет. Окончательную антисептическую обработку и активацию ирриганта осуществляли разработанным способом вакуумно-струйной ирригации — 1-я группа (. Анализ сканов показал, что вакуумно-струйный способ ирригации обеспечивает эффективную очистку просвета корневого канала в апикальной зоне в 90% случаев. Ирригация из эндодонтического шприца с ультразвуковой активацией в 67% случаев. Удаление смазанного слоя на всем протяжении корневого канала в 1-й группе образцов наблюдается в 100%. Во 2-й группе полного удаления смазанного слоя в апикальной зоне канала не достигнуто ни в одном случае. Анализ микрофотографий гистотопографических поперечных срезов корней зубов 2-й исследуемой группы выявил в околопульпарном дентине многочисленные кавитационные полости, которые в пришеечной и средней трети корня, сливаясь, образуют очаги деструкции диаметром 10—15 мкм. В 1-й группе образцов на всем протяжении корня зуба определялось типичное строение околопульпарного дентина с развитой сетью дентинных канальцев, неповрежденным пери- и интертубулярным матриксом.. Данные экспериментального исследования позволяют сделать вывод о том, что использование способа вакуумно-струйной ирригации корневых каналов обеспечивает более качественную очистку корневых каналов, полное удаление смазанного слоя без нарушения структуры дентина корня.

Topics: Adult; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The present study evaluated the effect of passive ultrasonic activation (PUI) of EDTA solution followed by conventional irrigation with 2 concentrations of sodium hypochlorite (NaOCl) on smear layer removal.. Fifty single-root mandibular premolars were chemomechanically prepared with ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) nickel-titanium rotary instruments and 1% NaOCl. The roots were cleaved, and the dentin surfaces were analyzed with scanning electron microscopy operated at a low vacuum. Images were obtained from previously demarcated areas in each root canal third. The teeth were reassembled and distributed into 5 groups according to the final irrigation protocols (n = 10): group 1, EDTA/PUI + 1% NaOCl; group 2, EDTA/PUI + 5% NaOCl; group 3, EDTA/CI + 1% NaOCl; group 4, EDTA/CI + 5% NaOCl; and group 5 (negative control), saline solution/PUI. After irrigation, the teeth were reseparated and prepared for conventional high-vacuum scanning electron microscopy of the same dentin surface that was previously analyzed. The amount of debris was classified using a 4-point scoring system. Data were analyzed with Kruskal-Wallis and Dunn tests at α = 0.05.. Groups 1 and 2, which used PUI and different concentrations of NaOCl, were not significantly different; however, they differed significantly from group 3 (P < .05). With respect to canal cleanliness at different root thirds, all groups showed the worst cleaning at the apical third.. PUI activation of the EDTA irrigant is required when canal debridement is performed with EDTA and a lower concentration of NaOCl.

Topics: Bicuspid; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

The aim of this study was to compare the efficiency of four final irrigation protocols in smear layer removal and bacterial inhibition in root canal systems. Thirty roots inoculated with Enterococcus faecalis were prepared with ProTaper Universal files. The teeth were disinfected by conventional needle irrigation, sonic agitation using the EndoActivator device, passive ultrasonic irrigation, or an M3 Max file. Teeth with no root canal preparation served as blank controls for the establishment of the infection baseline. Teeth with preparation but no final irrigation served as a post-instrumentation baseline. After the final irrigation, the teeth were sectioned in half. One half of each tooth was examined by scanning electron microscopy (SEM) to assess smear layer removal using a five-point scale. The other half was examined by confocal laser scanning microscopy (CLSM) using the LIVE/DEAD BackLight bacterial viability kit to evaluate the depth of bacterial survival in dentinal tubules. SEM analysis revealed no significant difference in smear layer removal throughout the whole canal among the EA, PUI, and M3 Max groups (P > 0.05). CLSM revealed that PUI achieved the greatest bacterial inhibition depth in the coronal ((174.27 ± 31.63) μm), middle ((160.94 ± 37.77) μm), and apical ((119.53 ± 28.49) μm) thirds of the canal (all P < 0.05 vs. other groups). According to this comprehensive SEM and CLSM evaluation, PUI appears to have the best infection control ability in root canal systems.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The present study evaluated the effects of using heated distilled water (HDW), with or without continuous ultrasonic irrigation (CUI), on smear layer removal and deterioration of root dentine microstructure.. After chemomechanical preparation, 60 human teeth were longitudinally cleaved into two halves for smear layer quantification at the cervical-third, middle-third and apical root-third of the canal space. After reassembly, the root canals were irrigated with 17 % EDTA, followed by one of the six final irrigation protocols (n = 10) - G1: conventional irrigation (CI)+NaOCl at 25 °C; G2: NaOCl at 25 °C + CUI; G3: CI with DW at 25 °C; G4: DW at 25 °C + CUI; G5: CI + HDW at 65 °C; G6: HDW at 65 °C + CUI. Tooth-halves were processed and examined by scanning electron microscopy. The percentage of opened dentinal tubules in the irrigated areas of the canal space was expressed as a percentage of the total surface area. Dentine erosion was classified by numeric scores. Smear layer removal was analysed with ANOVA and Student-Newman-Keuls tests; dentine erosion was analysed with Cohran-Mantel-Haenstel statistic (α = 0.05).. The cervical-third had a higher percentage of open dentinal tubules for all groups (p < 0.05). In G2, the middle-third had a lower percentage of open tubules, which was significantly different from the other groups (p < 0.05). Groups that utilised NaOCl as the final irrigant had more extensive erosion when CUI was used.. Heated distilled water, with or without CUI, was as efficient as 1 % NaOCl in the final cleaning of the instrumented canal space. The use of HDW produces less extensive dentine erosion.. Heated distilled water removes smear layers with less deleterious effects on dentine microstructure and may be considered a final irrigant after mechanical preparation and EDTA chelation.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Ultrasonics; Water

To evaluate the nanohardness reduction and erosion in root canal dentine after application of 17% ethylenediaminetetraacetic acid (EDTA), 9% etidronic acid (HEBP) and 2% peracetic acid (PAA) either alone or combined with sodium hypochlorite (NaOCl).. One hundred and sixty single-rooted teeth were decoronated and their root canals were chemomechanically prepared. For the nanohardness evaluation, 80 roots with instrumented canals were split longitudinally into two halves. Dentine blocks with a length of 7 mm were obtained from the middle third of one half of each tooth and were embedded in epoxy resin blocks exposing the root canal walls. Initial nanohardness values of root canal dentine were measured for each specimen using a nanoindenter with a Berkovich tip. The specimens were divided into seven experimental (n = 10) and one control (n = 10) group according to the final irrigation regimens: Group 1: 2.5% NaOCl, Group 2: 17% EDTA, Group 3: 2.5% NaOCl-17% EDTA, Group 4: 2% PAA, Group 5: 2.5% NaOCl-2% PAA, Group 6: 9% HEBP, Group 7: 2.5% NaOCl + 9% HEBP and Group 8: Distilled water (control). The measurement of the nanohardness values was repeated for each specimen after being exposed to the irrigants. The nanaohardness reduction of each sample was calculated and recorded. The other 80 instrumented root canals were used for scanning electron microscope (SEM) evaluation. First, they were irrigated with the same protocols stated above and longitudinally split into two halves. One half of each root canal was viewed using SEM for the amount of erosion. The erosion scores were recorded. Data were analysed statistically using Kruskal-Wallis and Bonferroni-adjusted Mann-Whitney U-tests with a significance level of 0.05.. Use of etidronic acid and NaOCl + HEBP reduced the nanohardness values significantly more than the other experimental solutions (P < 0.05). There was no significant difference between the values for the nanohardness reduction in the samples irrigated with a single chelator and chelator combined with NaOCl (P > 0.05). Peritubular and intertubular erosion were observed in the samples irrigated with HEBP and NaOCl + HEBP.. Final irrigation of root canals using etidronic acid alone or combined with NaOCl was associated with structural alterations in root canal dentine of extracted teeth.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Peracetic Acid; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To compare the effectiveness of erbium:yttrium-aluminum-garnet laser, GentleWave irradiation, photodynamic therapy (PDT), and sodium hypochlorite in smear layer removal and dentin permeability with a scanning electron microscope (SEM).. Seventy-five recently extracted single-rooted teeth (maxillary second premolars) were randomly divided into 5 groups of 15 each. Group I teeth was the control group in which conventional root canal preparation (RCP) [17% ethylenediaminetetraacetic acid (EDTA)] was done without laser irradiation, group II teeth underwent RCP and GentleWave™ treatment, group III teeth were subjected to Er:YAG laser irradiation, group IV uses low-level 660 nm (PDT), and group V samples were irrigated with 5.25% NaOCl. All samples were viewed under the SEM. Images at the coronal, middle, and apical part of the root canal were obtained at ×1000. A scoring system for smear layer removal and debris removal scoring was used for analysis.. Smear layer removal was significantly higher at different points (coronal, middle, and apical area) in group I, followed by V, IV, II, and group III in declining order (. Ethylenediaminetetraacetic acid and NaOCl are effective in smear layer removal. Er:YAG laser-activated RCP was comparatively efficient in cleaning the smear layer and opening dentinal tubules.. Er:YAG laser-activated RCP was comparatively efficient in cleaning the smear layer and it can be used for effective removal of smear layer for clinical usage.

Topics: Aluminum; Dental Pulp Cavity; Edetic Acid; Erbium; Humans; Lasers, Solid-State; Microscopy, Electron, Scanning; Photochemotherapy; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Yttrium

This study evaluates the effectiveness of different activated irrigation techniques on removal of debris and smear layer from curved root canals. Ninety mandibular molars with a root canal curvature between 20 and 40 degrees were assigned to 4 groups (n = 20): syringe irrigation (SI), passive ultrasonic activation (PUI), sonic activation with EDDY (ED) or EndoActivator (EA) and a control group. Mesiobuccal root canals were prepared to size 40, 0.04 and irrigated with NaOCl (3%) according to the respective technique. Roots were split longitudinally and subjected to scanning electron microscopic analysis. Presence of debris and smear layer was evaluated using 5-grade scoring systems with 200× and 1000× magnification, respectively. Data were analysed with nonparametric analysis for ordinal longitudinal data (α = 5%). Activation of the irrigant significantly improved smear layer removal (P < 0.05). Regarding debris, only activation with EA and ED was significantly more effective than SI (P < 0.05). No activation technique was able to eliminate debris and smear layer completely from curved root canals.

Topics: Dental Pulp Cavity; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

This study evaluated different irrigation methods in smear layer removal from the root canal walls using maleic acid (MA). Maxillary anterior teeth (N=30, n=10 per group) were decoronated, canals were enlarged with Protaper (size F4) and allocated to three groups: EndoUltra: 2.5 ml of 7% MA was irrigated for 30 s, followed by EndoUltra activation for 30 s; EndoSafe: EndoSafe irrigation system was used for 1 minute using 5 ml of 7% MA; Side-vented needle: 30 gauge needle irrigation was performed for 1 min using 5 ml of 7% MA. After SEM analysis, the inter-examiner reliability was verified using Kendall's Co-efficient and data were analyzed using Pearson Chi-Square test. No statistical significant differences were found between the two examiners (p⟩0.05). In intra-group comparison, needle and EndoSafe irrigation demonstrated significantly better smear layer removal at middle third of the root canal system (p⟨0.05) when compared to apical third. In inter-group comparison, smear layer was minimally removed with needle irrigation. In the apical third, EndoUltra group removed smear layer more effectively. Endosafe needle irrigation in combination with 7% MA removed the smear layer in the root canal at best, while the EndoUltra performed the best at the apical third of the root.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Reproducibility of Results; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The aim of this study was to evaluate the removal of the smear layer by some commonly used (needle-and-syringe irrigation, sonic activation, ultrasonically activated irrigation) and new root canal irrigation strategies (negative pressure irrigation and polymer rotary file) using a novel approach by comparing pre- and post-experimental images. Prepared root canals (n = 50) were subjected to a split tooth model and divided into 5 groups (n = 10): (1) needle-and-syringe irrigation (control); (2) sonic activation (SA); (3) negative pressure irrigation with continuous warm activated irrigation and evacuation (CWA); (4) polymer finishing file (FF); (5) ultrasonically activated irrigation (UAI). Smear layer scores and percentage of open dentinal tubules (%ODT) were evaluated by 2 examiners before and after irrigation procedures, from the middle and apical thirds of the root canal, on scanning electron microscopic images. Data were analysed using Kruskal-Wallis and post hoc tests at P = 0.05. Needle-and-syringe irrigation (control) showed no significant difference (both smear score and %ODT) compared to the pre-experimental value (P > 0.05). All other groups showed lower smear scores and higher %ODT, compared to the control (P < 0.05). The lowest smear score and highest %ODT were observed in the CWA group, which was significantly different from all other groups (P < 0.05). SA group showed significantly higher smear scores and lower %ODT than FF or UAI (P < 0.05). CWA showed superior removal of smear layer in the middle and apical thirds of the root canal compared to the other irrigation strategies.

Topics: Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

To investigate whether a minimally invasive basic root canal preparation technique has an influence on root canal cleanliness in extracted mandibular molar teeth.. A total of 80 root canals (40 mesio-buccal and 40 mesio-lingual) from 40 mandibular molars were included. The teeth were divided equally into four different experimental groups depending on the subsequently root canal preparation technique: Group 1: a basic preparation was performed up to size 20, .04 taper; Group 2: a basic preparation was performed up to size 2, .06 taper; Group 3: a basic preparation was performed up to size 25, .04 taper; and Group 4: a basic preparation was performed up to size 25, .06 taper. After the use of each instrument, each root canal was irrigated with 2.5 mL of 6% sodium hypochlorite for 30 s. Then, 1 mL NaOCl was activated for 20 s using an EDDY sonic tip. Final irrigation was performed using a total of 5 mL of 17% EDTA solution. The roots were then split longitudinally and all root canal thirds were observed through scanning electron microscopy (SEM) to evaluate the presence of superficial debris and smear layer using a scoring system. Data were statistically analysed using the Kruskal-Wallis and Bonferroni tests with a level of significance set at P < 0.05.. In all groups, there was significantly more residual debris and smear layer in the apical third (P < 0.05), with no differences between the middle and coronal thirds (P > 0.05). For both the parameters analysed, there was no difference amongst the groups in the middle and coronal thirds (P > 0.05), whilst in the apical third significantly less debris and smear layer was found in specimens from groups 3 and 4 than for groups 1 and 2 (P < 0.05).. All basic root canal preparation techniques were associated with less debris and smear layer on the canal walls in the middle and coronal thirds, without differences among them. Even though debris and smear layer were always present in the apical third, an apical size of 25 resulted in significantly cleaner canals walls compared to a size 20.

Topics: Dental Pulp Cavity; Humans; In Vitro Techniques; Mandible; Microscopy, Electron, Scanning; Molar; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Maleates; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

This study evaluated the influence of canal irrigation protocols with 5.25% calcium hypochlorite [Ca(OCl)

Topics: Bicuspid; Calcium Compounds; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

To compare the smear layer removal ability and mineral content of root canal dentine after initial irrigation with NaOCl and final irrigation with MTAD, QMix, and 17% EDTA. Forty extracted human maxillary incisors before root canal preparation and irrigation with NaOCl were randomly divided into four groups (n = 10) according to the type of final irrigants used: MTAD, QMix, 17% EDTA, and control (sterile distilled water). Scanning electron microscopy (SEM) was used to assess the presence of smear layer. SEM energy-dispersive X-ray spectroscopy was used to quantify dentin mineral composition in MTAD, QMix, 17% EDTA group, and in no-treatment samples (no-treatment group; n = 10). Among the various chelating agents, there were no significant differences in the smear layer removal in the middle and coronal thirds (p > .05). In the apical third, QMix removed significantly more smear layer than 17% EDTA (p < .05), but similarly to MTAD (p > .05). Final irrigation with MTAD resulted in a significant increase in the carbon (C) value compared to EDTA (p < .001). There was no significant difference in the mineral composition between the MTAD and the QMix group, although the values of the mineral elements were significantly altered in the MTAD group. QMix had smear layer removal capability similar to MTAD but better than EDTA in the apical third. MTAD yielded the most pronounced effect on mineral component of root dentin; however, differences were significant only for C level compared to 17% EDTA.

Topics: Biguanides; Citric Acid; Dental Pulp Cavity; Dentin; Doxycycline; Edetic Acid; Humans; Microscopy, Electron, Scanning; Minerals; Polymers; Polysorbates; Smear Layer; Sodium Hypochlorite; Spectrometry, X-Ray Emission; Treatment Outcome

To evaluate and compare the smear layer removal efficacy using two different concentrations of apple vinegar.. 48 single-rooted human teeth with conical roots and canals were randomly divided into four groups and prepared by using a nickel-titanium rotary system (Flexmaster). The final irrigation regimens used were: Group A (negative control group) in which distilled water only was used: Group B (positive control group) in which 2.5% NaOCL was used during instrumentation and 17% EDTA as a final irrigant; Group C (experimental group) in which the 5% apple vinegar was used as a root canal irrigant during instrumentation and as a final irrigant; and Group D (experimental Group 2) in which the diluted apple vinegar was used as a root canal irrigant during instrumentation and as a final irrigant. Specimens were then examined under a scanning electron microscope and scored for smear layer removal on the coronal, middle and apical thirds.. 5% apple vinegar was significantly more effective in smear layer removal only in the apical third (P< 0.001). However, diluted apple vinegar was comparable to 5% apple vinegar and 2.5% NaOCl and 17% EDTA, within the coronal and middle levels of the root canal (P<0.05).. 5% apple vinegar was significantly more effective in smear layer removal only in the apical third. Diluted apple vinegar demonstrated comparable results to the control groups. Thus, it is possible to use diluted apple vinegar as an irrigant after investigating its antimicrobial efficiency and the effect on sealing ability.

Topics: Acetic Acid; Dental Pulp Cavity; Edetic Acid; Humans; Malus; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

This study aimed to evaluate the effectiveness of XP-endo Finisher (XPF) file and passive ultrasonic irrigation (PUI) in the smear layer removal of the root canal.. A total of 60 human single-rooted premolars were selected and decoronated to standardize their canal length to 16 mm. Tooth samples were prepared using a S3 rotary system to prepare root canal with the file size of 3S and then randomly divided into 6 groups according to the final irrigation protocol, as follows: XPF 3 mL of 3% NaOCl for 1 min (group A); XPF 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% ethylene diamine tetraacetic acid (EDTA) for 1 min (group B); PUI of 3 mL of 3% NaOCl for 1 min (group C); PUI of 3 mL of 3% NaOCl for 1 min, followed by 4 mL of 17% EDTA for 1 min (group D); 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle (group E); and 3 mL of 3% NaOCl for 1 min by using a syringe and a 30 G side-vented needle, followed by 4 mL of 17% EDTA for 1 min (group F). After the completion of the root canal preparation, the teeth were split into two longitudinally. The mean numbers of the visible open dentinal tubules in the apical and middle thirds of the root canals were evaluated via scanning electron microscope.. The whole surfaces of the root canals in groups A, C, and E were covered by a smear layer. Groups A and C possessed significantly higher number of visible open dentinal tubules than in group E (P<0.05), with statistically insignificant difference between groups A and C (P>0.05). The apical third of the samples in groups B and D and in the middle thirds of canals in group F exhibited a small amount of smear layer, and the dentinal tubules were open or semi-open. The root canal surfaces in the apical third of the samples in group F were covered by a smear layer, and the dentinal tubules were sealed or semisealed. The smear layers in the middle third of the samples in groups B and D were removed, and the dentinal tubules were more visibly open than those of the four other groups (P<0.05). The difference between groups B and D were statistically insignificant (P>0.05).. The difference between XPF and PUI in terms of the smear layer removal of the root canals was insignificant. Hence, XPF, as a new irrigation agitation technique, can aid in improving smear layer removal.. 目的 评估XP-endo Finisher（XPF）锉与被动超声冲洗（PUI）对根管内壁玷污层的清除效果。方法 选择60颗离体单直根管下颌前磨牙，距根尖16 mm处截冠，采用S3镍钛锉预备到3S，根据终末处理方式不同将样本随机分成6组。A组：3 mL 3%次氯酸钠溶液联合XPF处理1 min；B组：3 mL 3%次氯酸钠溶液联合XPF处理1 min，再用4 mL 17%乙二胺四乙酸（EDTA）溶液冲洗1 min；C组：3 mL 3%次氯酸钠溶液联合PUI处理1 min；D组：3 mL 3%次氯酸钠溶液联合PUI处理1 min，再用4 mL 17%EDTA溶液冲洗1 min；E组：3 mL 3%次氯酸钠溶液30号侧方冲洗针冲洗1 min；F组：3 mL 3%次氯酸钠溶液30号侧方冲洗针冲洗1 min，再用4 mL 17%EDTA溶液冲洗1 min。采用扫描电子显微镜观察玷污层形态，并比较根尖1/3区、根中1/3区牙本质小管开口数。结果 A、C、E组实验样本整个根管壁都有玷污层覆盖，A组与C组牙本质小管开口数明显高于E组（P<0.05），而A组与C组的差异无统计学意义（P>0.05）；F组根中区、B组和D组根尖区有少量玷污层覆盖，牙本质小管开放或半开放；F组根尖区可见玷污层，牙本质小管封闭或半封闭；B和D组根中区根管壁玷污层均被有效去除；在根尖1/3区和根中1/3区，B组与D组牙本质小管开口数高于其他4组（P<0.05），而B组和D组间的差异无统计学意义（P>0.05）。结论 XPF锉对根管内壁玷污层的清洁效果与PUI无明显差异，可用于根管预备后提高根管清洁效果。.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The purpose of this study was to compare the efficacy of different irrigation protocols on smear layer removal in root canals of primary teeth by scanning electron microscopy (SEM).. The study was conducted with 40 extracted maxillary primary incisor teeth divided into four groups (n = 10) as 1% sodium hypochlorite (NaOCl), 10% ethylenediaminetetraacetic acid (EDTA)+1% NaOCl, 6% citric acid (CA)+1% NaOCl, and 0.9% physiological saline (PS). After the irrigation procedures, root canal walls were examined by SEM and the efficacies of irrigation solutions in smear layer removal were scored and compared. Data were analyzed using Kruskal-Wallis, Friedman and Siegel Castellan tests.. The smear layer removal was found to be statistically more effective in groups of 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl when compared with the other groups (p < .05). Smear removal efficacy was statistically significantly higher in coronal and medium thirds when compared with the apical regions in the experimental groups.. It was concluded that 10% EDTA + 1% NaOCl and 6% CA + 1% NaOCl could be alternative irrigation protocols regarding smear layer removal. However, due to the absence of erosive dentinal changes, it might be suggested that using 6% CA + 1% NaOCl can be recommended compared to 10% EDTA + 1% NaOCl in primary root canals.

Topics: Chelating Agents; Citric Acid; Dental Pulp Cavity; Disinfection; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth, Deciduous

The study is aimed at investigating the smear layer, formed on the walls of dental root canals as a result of endodontic treatment, by using scanning electron microscope (SEM) and determining its removal and/or modification quality after applying water solution of 18% ethylenediaminetetraacetic acid (EDTA) and gel. 50 extracted teeth preliminary prepared using Step-Back technique has been studied. Experimental teeth were randomly divided into the following 3 groups: control group (20 teeth), study group I (15 teeth) and study group II (15 teeth), respectively, irrigated by water solution of 18% ethylenediaminetetraacetic acid (EDTA). SEM examination was carried out for 3 different areas of preliminary prepared separated dental roots: coronal, middle and apical portions. The entire study was based on the analysis of 900 electron microscope photo- images. SEM study revealed formation of the thick smear layer on the surface of root canal dentin, practically covering the openings of canal tubules. Both the water solution and/or gel of 18% ethylenediaminetetraacetic acid provided partial or complete removal of the mentioned smear layer; among them, EDTA 18% water solution appeared to be more effective for coronal and middle thirds of dental root (P<0.05). Removal of the smear layer from root canals by using the chelating agents was less effective in the apical third. Having studied these areas, the portions covered with the smear layer and blocked dentinal tubules on canal surfaces were revealed.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The aim of this study was to evaluate the effect of peracetic acid (PAA) as a single irrigant on the smear layer, on the intraradicular dentinal bond strength, and on the penetrability of an epoxy-based resin sealer into the dentinal tubules. A total of 120 roots were distributed into 4 groups according to the irrigant used in root canal preparation: 1% PAA (PAA); 2.5% NaOCl followed by final irrigation with 17% EDTA and 2.5% NaOCl (NaOCl-EDTA-NaOCl); 2.5% NaOCl (NaOCl); and saline solution (SS). The smear layer was evaluated using scanning electron microscopy. The bond strength of an epoxy-based resin sealer (AH Plus) to root dentin was evaluated by the push-out test and penetrability of the sealer into dentinal tubules was observed by confocal laser microscopy. The results were analyzed by the Kruskal-Wallis and the Dunn post-test (α = 0.05). The use of 1% PAA as single root canal irrigant provided smear layer removal and improved the penetrability and bond strength of AH Plus to root dentin in a manner similar to that of the NaOCl-EDTA-NaOCl group (p > 0.05). The NaOCl and SS groups had higher values of smear layer and lower values of sealer penetrability and dentin bond strength than the PAA and NaOCl-EDTA-NaOCl groups (p < 0.05). Thus, 1% PAA has the potential to be used as a single irrigant in root canals.

Topics: Dental Bonding; Dental Pulp Cavity; Dentin; Edetic Acid; Epoxy Resins; Humans; Materials Testing; Microscopy, Confocal; Microscopy, Electron, Scanning; Peracetic Acid; Reference Values; Reproducibility of Results; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

This study evaluated the irrigation extrusion and smear layer (SL) removal of continuous ultrasonic irrigation (CUI). Forty root canals were shaped, embedded in warm sterile saline agar colored with 1% acid red, and distributed into four groups; three groups had the final irrigation sequence of sodium hypochlorite and EDTA solutions performed by using syringe irrigation (SI), EndoVac (EV), and CUI, respectively. Group 4 had the canals ultrasonically irrigated with saline (CUIS). Irrigant extrusion was verified by a color change of the agar. The SL was evaluated under scanning electron microscope. Irrigant extrusion was observed in two and four teeth in the CUI and SI, respectively, whilst none had irrigant extruded in the EV. In term of SL, the CUI was comparable to EV at 1 and 3 mm but different to SI at 1 mm. Although CUI might clean the root canal system effectively, it was unable to avoid irrigant extrusion.

Topics: Edetic Acid; In Vitro Techniques; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Syringes; Therapeutic Irrigation; Ultrasonic Therapy

To evaluate the intratubular antimicrobial activity of several oxidant and chelating agents associated with or without surfactants in experimentally infected root canals, using confocal laser scanning microscopy.. Twenty-four dentine blocks from bovine incisors were contaminated for 5 days with Enterococcus faecalis (ATCC- 29212). Ten contaminated dentine specimens were irrigated for 5 min with 5.25% NaOCl followed by 17% EDTA for 2 min, and the other 10 with Hypoclean for 5 min followed by Tetraclean NA for 2 min. The remaining four specimens were used as positive and negative controls (two samples each). Then, dentine blocks were stained with Live/Dead BacLight for analysis of the remaining live or dead bacteria using confocal laser scanning microscopy. Comparison between and within groups was performed using the Mann-Whitney test for independent samples and the Wilcoxon signed-rank test, respectively.. After exposure to irrigants, the positive control group had a median of 67.41% of viable bacteria (95% CI: 48.15, 78.9), whilst the NaOCl+EDTA group and Hypoclean+Tetraclean NA group had 3.77% (1.28, 15.92) and 0.87% (-0.42, 4.30) of viable bacteria, respectively. These results were significantly different from each other, both overall and distinct by region (cervical and medium third), or depth (superficial and deep layer) (P < 0.01 in all cases).. The use of adjunctive agents reducing the surface tension associated with oxidant and chelating agents improved the antimicrobial activity of irrigating solutions and intratubular decontamination against Enterococcus faecalis, possibly due to better removal of the smear layer and deeper penetration into dentinal tubules.

Topics: Animals; Anti-Infective Agents; Cattle; Cetrimonium Compounds; Chelating Agents; Citric Acid; Dental Pulp Cavity; Dentin; Doxycycline; Drug Combinations; Edetic Acid; Enterococcus faecalis; Incisor; Microbial Viability; Microscopy, Confocal; Oxidants; Polypropylenes; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Surface Tension

To characterize chemical degradation of the principal constituents of dentine after exposure to NaOCl and EDTA using Infrared Spectroscopy (ATR-FTIR).. Ground dentine particles, from extracted permanent human molars, were passed through sieves of 38 to 1 000 μm to provide six size ranges. Portions (250 mg) of each size range were reacted with 5 mL of 2.5% NaOCl for 2-10 min; or 17% EDTA for 5-1440 min. Powders larger than 75 μm were also sequentially exposed to NaOCl/EDTA/NaOCl each for 10 min. All experiments were repeated five times. Reacted and unreacted powders were washed and dried. Particles larger than 75 μm were then reground. FTIR spectra of unground and reground reacted particles enabled assessment of particle surface versus bulk chemistry, respectively, plus estimation of reaction depth. Changes in the ratio of the 1 640 cm. Surface collagen fraction declined by ~40% within 2 min of NaOCl exposure, and plateaued at ~60% between 6-10 min. Bulk spectra showed average depth of collagen loss at 10 min was 16 ± 13 μm. Ten minute EDTA exposure caused ~60% loss of surface phosphate. Average depth of phosphate loss was 19 ± 12 μm and 89 ± 43 μm after 10 and 1 440 min EDTA immersion, respectively. Sequential NaOCl/EDTA immersion yielded a 62 ± 28 μm thick phosphate-depleted surface. Sequential NaOCl/EDTA/NaOCl treatment resulted in approximately 85 μm of collagen loss.. Data revealed the sequential depletion of collagen by NaOCl and apatite by EDTA in dentine, simultaneously exposing the other moieties. Alternate exposure to NaOCl and EDTA therefore enhances the depth of erosion.

Topics: Apatites; Collagen; Dentin; Durapatite; Edetic Acid; Humans; Molar; Phosphates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Spectroscopy, Fourier Transform Infrared

To evaluate the smear layer removal and wettability of AH Plus sealer on root canal dentin treated with MA (maleic acid), MA + CTR (cetrimide) and MA + CTR + CHX (chlorhexidine) as final irrigating regimens.. For smear layer removal, 40 teeth were instrumented to size F4 and divided into four groups: (1) 7% MA, (2) 7% MA + 0.2% CTR, (3) 7% MA + 0.2% CTR + 2% CHX, (4) distilled water (control). After irrigation, teeth were subjected to SEM analysis. For contact angle analysis, 20 teeth were split longitudinally and divided into four groups similar to smear layer analysis. AH plus sealer was placed on each specimen and contact angle was analysed.. In both smear layer (p = .393) and contact angle analysis (p = .961), there was no significant difference between the groups MA and MA + CTR. However, MA + CTR + CHX removed smear layer less effectively (p = .023) and increased the contact angle of the sealer (p = .005). In smear layer analysis, specimens in negative control group were heavily smeared. In case of contact angle analysis, samples in the control group had least contact angle.. MA alone or in combination with CTR removed smear layer effectively and increased the wettability of AH plus sealer to root canal dentin.

Topics: Chlorhexidine; Dental Pulp Cavity; Humans; Maleates; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Wettability

The optimal irrigating solution with antimicrobial and dentin cleansing properties for post space preparation for fiber posts is unclear. Peracetic acid is one option but is available in various chemical formulations that require evaluation.. The purpose of this in vitro study was to evaluate dentin surface cleanliness based on the presence of a smear layer and the number of open dentin tubules. It also investigates the chemical composition of residues after canal irrigation with a 1% peracetic acid solution (PA) at low or high concentration of hydrogen peroxide during the preparation of intracanal fiber posts.. After filling the root canals of 40 mandibular incisors, a rotary instrument was used for intracanal preparation to place fiber posts. The teeth were divided into 4 groups (n=10) according to the post space irrigation protocol as follows: CG (control): distilled water; NA (NaOCl): 2.5% sodium hypochlorite; LH: PA with low concentration of hydrogen peroxide; and HH: PA with high concentrations of hydrogen peroxide. After irrigation, the teeth were sectioned, and the intracanal dentin surface was subjected to analysis using energy dispersive spectroscopy to evaluate chemical composition and to scanning electron microscopy (×500) to evaluate the presence of the smear layer. The number of open dentin tubules was measured by scanning electron microscopy analysis (×2000) using photo-editing software. ANOVA and the Tukey test (α=.05) were used to evaluate the data, except for the presence of a smear layer, for which the Kruskal-Wallis and Dunn tests were used (α=.05).. The highest concentrations of oxygen in the dentin residues were detected in LH and HH (P<.05); CG and NA showed similar oxygen concentrations (P>.05). NA had a higher concentration of chlorine (P<.05), whereas LH had a lower amount of smear layer and a larger number of open dentin tubules than the other groups (P<.05). These were equivalent to each other (P>.05), except for HH, which also had a larger number of open dentin tubules than CG and NA (P<.05).. PA 1% with a low concentration of hydrogen peroxide yielded a lower amount of smear layer and a larger number of open dentin tubules in the dentin of the post space when compared with PA 1% with a high concentration of hydrogen peroxide, despite maintaining a similar oxygen concentration in these dentin residues.

Topics: Dentin; Humans; Hydrogen Peroxide; In Vitro Techniques; Incisor; Mandible; Microscopy, Electron, Scanning; Peracetic Acid; Post and Core Technique; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Spectrometry, X-Ray Emission; Surface Properties

To investigate the release of growth factors into the root canal space after various final irrigants during regenerative endodontic procedures. The residual cytotoxic effect of final irrigants on stem cells from the apical papilla (SCAP) was also examined.. To measure the release of TGF-β1, root segments (8 mm long) were irrigated with 1.5% NaOCl followed by 20 mL of final irrigants; Saline, 17% EDTA, 10% citric acid, 10% or 37% phosphoric acid. Specimens were then immersed into culture medium for 24 h and the supernatants were collected to measure TGF-β1 by ELISA. For the cytotoxicity of residual final irrigants, dentine chips (5 × 5 × 1 mm) treated with irrigants as above were placed in the upper chamber of transwell system. Stem cells from the apical papilla were incubated indirectly in the lower chamber for 24 h and MTS assay was performed after 24 h. The surfaces of irrigated root canals were examined for smear layer with a scanning electron microscope (SEM). Log transformation was performed for ELISA data to compare different groups (one-way ANOVA, α = 0.05).. Ten percent citric acid released the greatest amount of TGF-β1 amongst all groups, which was significantly different to 17% EDTA (P < 0.01). All dentine chips irrigated with the irrigants showed no significant difference of cytotoxicity on SCAP compared to nonirrigated dentine (P > 0.05). SEM revealed completely open dentinal tubules in 10% citric acid, whereas 17% EDTA was associated with partially open dentinal tubules.. Ten percent citric acid was effective as a final irrigant for releasing TGF-β1 with good biocompatibility in regenerative endodontics.

Topics: Citric Acid; Dental Papilla; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Phosphoric Acids; Regenerative Endodontics; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Saline Solution; Smear Layer; Sodium Hypochlorite; Stem Cells; Transforming Growth Factor beta1

The objective of this study was to compare antibacterial and smear layer removal efficacy of the erbium:yttrium-aluminium-garnet (Er:YAG) laser irradiation by photon-induced photoacoustic streaming (PIPS), neodymium:yttrium-aluminium-garnet (Nd:YAG), and diode lasers and conventional irrigation agent in primary molar root canals.. The selection, application, and activation of the irrigant are important factors affecting the success of the endodontic treatment.. Distal root canals of human primary mandibular molar teeth used for antimicrobial efficacy evaluation were first inoculated with Enterococcus faecalis (n = 25). Smear layer removal efficacy was evaluated on the noninoculated specimens (n = 20). The root canals in the first treatment groups were irrigated with a conventional technique using 5% sodium hypochlorite (NaOCl). In the laser groups, the root canals were irradiated with either Nd:YAG (1064 nm) or diode lasers (940 nm) followed by NaOCl irrigation agent. In the fourth groups, the NaOCl irrigation agent was activated with an Er:YAG laser (2940 nm) by PIPS tip using nonablative settings. Antibacterial efficacy was determined by viable counts of E. faecalis after treatments. The treated root canals were examined by scanning electron microscopy to determine the smear layer removal efficacy of treatments.. Statistically significant (p < 0.05) reductions in the number of E. faecalis were achieved in Nd:YAG and diode laser groups and Er:YAG laser by PIPS-activated irrigation groups compared to the NaOCl group. Er:YAG laser by PIPS-activated irrigation resulted in more cleaning of the root canal walls and a higher quantity of open tubules.. These findings suggest that Er:YAG laser by PIPS-activated irrigation can be considered as an effective irrigant agitation technique in pediatric endodontics.

Topics: Dental Pulp Cavity; Disinfectants; Enterococcus faecalis; Humans; Lasers, Semiconductor; Lasers, Solid-State; Low-Level Light Therapy; Molar; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tissue Culture Techniques

This study aimed to evaluate the fracture resistance of tooth crowns endodontically irrigated using different protocols.. A total of 76 bovine incisors were divided into four groups (n = 19): irrigation with distilled water (control; CON); conventional irrigation with positive apical pressure (PAP); passive ultrasonic irrigation using continuous flushing (PUI); and irrigation with PAP and heated sodium hypo-chlorite solution (PHS). The force required to fracture the crown was measured on a universal testing machine at an angle of 45°.. The CON group had higher fracture resistance (351.71 ± 58.66 N) than the PAP and PUI groups (140.96 ± 37.26 N; 167.49 ± 40.08 N respectively). The PHS group had the lowest fracture resistance value (115.15 ± 41.07 N). Irrigation protocols had a significant effect on crown resistance (p < 0.01).. Teeth subjected to irrigation with heated sodium hypochlorite showed decreased resistance to crown fracture.. The contact of the irrigating solution with the root canal walls potentially can cause their weakness, determining crown fracture.

Topics: Animals; Cattle; Dental Stress Analysis; Incisor; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Solutions; Therapeutic Irrigation; Tooth Crown; Tooth Fractures; Tooth, Nonvital

In recent years, the diode laser (810 nm) has been used for root canal disinfection, which plays an important role in endodontic therapy. This study was undertaken to evaluate the disinfecting ability of a diode laser in experimentally infected root canals of primary teeth.. Human retained mandibular primary anterior teeth without apical foramen resorption were selected and contaminated with Enterococcus faecalis for 21 days. The specimens were randomly divided into four groups: the negative group (no treatment), positive group (5.25% NaOCl), diode laser group (diode laser), and diode-NaOCl group (diode laser combined with NaOCl). The disinfecting abilities of the treatments were measured by the numbers of bacteria, scanning electron microscopy and confocal laser microscopy (live-dead staining).. Eighty teeth were selected. After irradiation and irrigation, the elimination of bacteria and the smear layer in the laser groups and positive group were significantly superior, compared with the negative group (p < 0.01). In the diode-NaOCl group, bacterial reduction reached nearly 100% on the surfaces of root canals; live bacteria were rarely observed, even in deeper dentinal tubules.. Use of a diode laser, especially in combination with NaOCl, was effective for disinfecting infected root canals of primary teeth.

Topics: Dental Pulp Cavity; Disinfection; Enterococcus faecalis; Humans; In Vitro Techniques; Lasers, Semiconductor; Microscopy, Confocal; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Tooth, Deciduous

The present study aimed to evaluate the antibacterial effect of a new peptide, DJK-5, used alone or mixed together with EDTA on mono- and multispecies biofilms in dentin canals covered by a smear layer with or without preceding sodium hypochlorite (NaOCl) irrigation.. One hundred twelve dentin blocks (224 final specimens) were prepared and divided into 56 groups, and Enterococcus faecalis or multispecies bacteria were introduced into dentinal tubules by centrifugation. After 1 week of cultivation, a uniform smear layer was created on the surface of the dentin blocks, and the samples were exposed to sterile water, 17% EDTA, 2% or 6% NaOCl, 10 μg/mL DJK-5, or a mixture of 8.5% EDTA +10 μg/mL DJK-5 or were combined treated with the solution in the following sequence: 2% or 6% NaOCl +10 μg/mL DJK-5, 2% or 6% NaOCl + 8.5% EDTA +10 μg/mL DJK-5, 2% or 6% NaOCl + 8.5% EDTA + 10 μg/mL DJK-5. Specimens without a smear layer treated by 6% NaOCl or 10 μg/mL DJK-5 served as the positive control. The irrigant exposure time was 3 or 10 minutes. The antibacterial efficacy was determined by live/dead staining and confocal laser scanning microscopy.. The smear layer reduced the antibacterial capacity of 6% NaOCl and 10 μg/mL DJK-5. The efficacy of 2% or 6% NaOCl followed by 10 μg/mL DJK-5 was superior to 10 μg/mL DJK-5 alone (P < .05) but inferior to 2% or 6% NaOCl + 8.5% EDTA + 10 μg/mL DJK-5 and 2% or 6% NaOCl + 8.5% EDTA + 10 μg/mL DJK-5 (P < .05). The mixture of 8.5% EDTA and 10 μg/mL DJK-5 had the same disinfection effectiveness as 10 μg/mL DJK-5 used alone (P < .05). Using 2% or 6% NaOCl before EDTA + peptide always resulted in the highest killing (P < .05).. The smear layer inhibits the disinfectant effect in dentin. Peptide DJK-5 showed a strong antibacterial effect against mono- and multispecies biofilms in dentin canals. The highest killing was measured when 6% NaOCl was followed by a mixture of EDTA and peptide DJK-5.

Topics: Anti-Bacterial Agents; Biofilms; Dental Pulp Cavity; Dose-Response Relationship, Drug; Drug Combinations; Drug Resistance, Bacterial; Edetic Acid; Enterococcus faecalis; Humans; In Vitro Techniques; Oligopeptides; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

The purpose of this study was to evaluate the effect of laser-activated irrigations (LAI) by using the Erbium: Yttrium Aluminum Garnet (Er:YAG) laser and the Erbium Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser on removing smear layer (SL) from the root canal wall.. LAI has been proposed as an adjuvant to conventional protocols of endodontic treatment to enhance the disinfection, which is a promising protocol for SL removal.. SL was generated by preparing the root canals of extracted human teeth to a #35/.04 M3 instrument. The SL then received treatments of one of the following: (A) NaOCl, 5.25% sodium hypochlorite (NaOCl) for 60 sec; (B) EDTA, 17% ethylenediamine tetraacetic acid (EDTA) for 60 sec; (C) NaOCl+EDTA, NaOCl, and EDTA for 30 sec each; (D) LAI+NaOCl, LAI with NaOCl for 60 sec; (E) LAI+EDTA, LAI with EDTA for 60 sec; and (F) LAI+NaOCl+EDTA, LAI with NaOCl, and EDTA for 30 sec each. Efficacies of SL removal were evaluated by using a five-grade scoring system under scanning electron microscopy.. The laser activations significantly enhanced the effect of the NaOCl, EDTA, and NaOCl+EDTA irrigations in removing SL. The efficacies of SL removal were presented in a descending order of LAI+NaOCl+EDTA, LAI+EDTA>LAI+NaOCl, NaOCl+EDTA>EDTA>NaOCl.. Among the treatments, the LAI+NaOCl+EDTA was the most effective protocol in removing SL from the entire root canal wall, which may be effective for root canal treatment.

Topics: Edetic Acid; Humans; Lasers, Solid-State; Low-Level Light Therapy; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

This study aimed to evaluate the effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin. Sixty root canals from mandibular incisors were instrumented and randomly divided into six groups (n = 10) according to the irrigant used: QMiX, 17% EDTA, 10% citric acid (CA), 1% peracetic acid (PA), 2.5% NaOCl (solution control), and distilled water (negative control). The chelating solutions were used to irrigate the canal followed by 2.5% NaOCl as a final flush. After the irrigation protocols, all specimens were rinsed with 10 mL of distilled water to remove any residue of the chemical solutions. Before and after the final irrigation protocols, dentin microhardness was measured with a Knoop indenter. Three indentations were made at 100 µm and 500 µm from the root canal lumen. Afterwards, the specimens were prepared for scanning electron microscopic analysis and the amount of dentin erosion was examined. Wilcoxon and Kruskal-Wallis tests were used to analyze the results with a significance level set at 5%. At 100 µm, all protocols significantly reduced dentin microhardness (p < .05), while at 500 µm, this effect was detected only in the EDTA and QMiX groups (p < .05). CA was the irrigant that caused more extensive erosion in dentinal tubules, followed by PA and EDTA. QMiX opened dentinal tubules, but did not cause dentin erosion. Results suggest that QMiX and 17% EDTA reduced dentin microhardness at a greater depth. Additionally, QMiX did not cause dentin erosion.

Topics: Biguanides; Citric Acid; Dental Pulp Cavity; Dentin; Edetic Acid; Hardness Tests; Humans; Materials Testing; Microscopy, Electron, Scanning; Peracetic Acid; Polymers; Random Allocation; Reproducibility of Results; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties; Tooth Erosion

The therapeutic effects of sodium hypochlorite (NaOCl) solutions are dependent on the levels of free available chlorine (FAC). Mixing these solutions with irrigants can result in significant reductions in FAC. Although the effect of some irrigants on FAC is known, the effect of other commonly used irrigants is not. Thus, the therapeutic ramifications of the concurrent use of these on the efficiency of NaOCl solutions is not known.. Aliquots of 5.2% (w/v) NaOCl solutions were admixed in proportions of 90:10, 80:20, and 50:50 with the following irrigants: octenidine dihydrochloride (OCT); SmearOFF (Vista Dental Products, Racine, WI), 17% EDTA; and 0.2%, 2%, and 5% chlorhexidine (CHX) solutions. Changes in FAC were measured by iodometric titration. Statistical differences between means were determined using a post hoc Tukey analysis test after an analysis of variance.. OCT appeared not to affect FAC and was significantly different than all other irrigants, except for 90:10 and 80:20 mixtures of low concentration (0.2%) CHX. CHX solutions showed a marked concentration- and mixture proportion-dependent detrimental effect on FAC. The reduction of FAC between different concentrations of CHX was statistically significant in 80:20 and 50:50 proportions, with 50:50 mixtures of 5% CHX having the greatest influence. Mixtures containing even small proportions of SmearOFF or EDTA exhibited significant losses in FAC.. OCT has little effect on FAC and can be used concurrently with NaOCl solutions. Higher concentrations of CHX significantly affect FAC. Their combined use with NaOCl solutions should be avoided. EDTA and SmearOFF should not be mixed with NaOCl solutions.

Topics: Anti-Infective Agents, Local; Chlorhexidine; Edetic Acid; Imines; Pyridines; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

The purpose of this study was to determine the effectiveness of laser-activated irrigation by photon-induced photoacoustic streaming (PIPS) in the reduction of Enterococcus faecalis in root canal disinfection, varying laser energy output, and sodium hypochlorite (NaOCl) concentration. For effective removal of the smear layer, the sequence and resting time of the final irrigation steps were modified compared with the standard PIPS protocol.. Eighty-six extracted single-rooted teeth were mechanically prepared, sterilized, and inoculated with E. faecalis for 4 weeks. Teeth were divided into 9 groups and treated with an Er:YAG laser using a PIPS 600/9 tip at the following parameters: 10 mJ or 20 mJ, 15 Hz, and a 50-microsecond pulse duration at 0.15 W or 0.3 W average power, respectively. Root canals were irrigated with different concentrations of NaOCl (ie, 1%, 3%, and 5% and activated using the adjusted PIPS protocol). The bacterial count was performed immediately after and 48 hours after decontamination and new incubation on an agar plate.. A statistically significant difference in bacterial counts (P < .05) was detected in all groups before and directly after the treatment and in groups treated with 5% NaOCl 48 hours after treatment. Scanning electron microscopic imaging showed an absence of bacteria and biofilm in the scanned areas after treatment with 5% NaOCl.. Laser-activated irrigation using 5% NaOCl and a modified PIPS protocol resulted in effective eradication of the bacterial biofilm and removal of the smear layer.

Topics: Biofilms; Colony Count, Microbial; Dental Pulp Cavity; Disinfection; Enterococcus faecalis; Humans; Lasers, Solid-State; Microscopy, Electron, Scanning; Photoacoustic Techniques; Photons; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite

The aim of this study was to evaluate the effect of maleic acid (MA) on both the bond strength of fibre post to root dentine and smear layer removal after post space preparation. Sixty, single-canal premolars were endodontically treated and randomly assigned to four groups: group 1 [0.9% saline solution (control]); group 2 [2.5% sodium hypochlorite (NaOCl)]; group 3 [17% ethylenediaminetetraacetic acid (EDTA) followed by 2.5% NaOCl]; and group 4 (7% MA followed by 2.5% NaOCl). Self-adhesive resin cement was used to test the adhesion of a glass-fibre post to the root dentine through a micropush-out test. Scanning electron microscopy was performed to examine and score the treated specimens for smear layer removal, and stereomicroscopy was applied to investigate the failure modes of fibre posts. Maleic acid exhibited the highest mean bond-strength values in the apical regions among all the groups. Most failure modes (31.9%) were adhesive-type failures between the dentine and luting materials. Maleic acid performed statistically significantly better than the other groups regarding smear layer removal, especially in the apical region. Maleic acid is an effective irrigant that can remove the smear layer, open dentinal tubules, and act as a high-efficiency final irrigant in activation protocols.

Topics: Bicuspid; Dental Bonding; Dentin; Edetic Acid; Humans; In Vitro Techniques; Maleates; Microscopy, Electron, Scanning; Post and Core Technique; Random Allocation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Tooth Root

The present study aimed to evaluate the effects of four endodontic chelating agents, followed by 2.5% sodium hypochlorite (NaOCl), as final irrigation regimens on organic and inorganic components of human root dentin. Sixty mandibular incisors were prepared and randomly divided into six groups (n = 10): QMiX, 1% peracetic acid (PA), 17% EDTA, 10% citric acid (CA), 2.5% NaOCl (solution control) and distilled water (DW-negative control). After irrigation with the chelating agents, a final flush was performed with 2.5% NaOCl. The specimens were split longitudinally in halves; one was designated for organic component analysis by polarized light microscopy (PLM) and the other for inorganic structure analysis by scanning electron microscopy (SEM). Scores data obtained in the PLM analysis were submitted to Kruskal-Wallis' test, followed by Dunn's test (p < .05). SEM findings were presented descriptively. NaOCl and DW groups showed uniformity in the fibrillar network and smear layer obliterating the dentinal tubules, while CA group presented alteration in organic and inorganic components of dentin. EDTA group did not show differences from others in the organic component, but altered the inorganic structure. QMiX and PA groups did not cause a significant morphological alteration in collagen and removed the smear layer without inorganic structure modification. As final irrigation, QMiX and PA solutions, followed by 2.5% NaOCl, showed better behavior than the other chelating agents tested, preserving organic and inorganic components of human root dentin.

Topics: Chelating Agents; Collagen; Dental Pulp Cavity; Dentin; Humans; Materials Testing; Microscopy, Electron, Scanning; Microscopy, Polarization; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The aim of this study was to determine the following: (i) the quantity of free chlorine in mixtures of equal proportions of sodium hypochlorite (NaOCl) with trisodium ethylenediaminetetraacetic acid (EDTAHNa. The solutions were mixed in a 1 : 1 ratio and then iodometrically titrated over time to determine the quantity of free available chlorine. The capability of organic matter dissolution by the solutions alone and the mixtures of irrigants was analysed by weighing bovine muscle tissue specimens before and after submission to the following groups (n = 10): G1 - 0.9% saline solution (control), G2 - 2.5% NaOCl, G3 - 17% EDTAHNa. EDTAHNa. Alkaline EDTANa

Topics: Animals; Calcium Chelating Agents; Cattle; Edetic Acid; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The aim of the present study is to evaluate the possible correlation between sealer penetration into dentinal tubules and sealing ability both in presence and absence of smear layer.. Fourteen maxillary central incisors were treated with 5.25 % NaOCl +10 % EDTA to remove the smear layer (SL-free group) or 5.25 % NaOCl without EDTA (SL group). Root canals were filled using #25 Thermafil Obturators with Topseal sealer labelled with 0.1 wt% rhodamine B. Sealing ability was measured as fluid filtration rate with a fluid-flow meter using water supplemented with 0.3 % calcein fluorescent dye. Specimens were sectioned, observed under confocal microscope to co-localize the presence of sealer (rhodamine B labelling) into dentinal tubules and gaps (calcein labelling) into the root canal. The depth of sealer penetration into dentinal tubules and the percentage of sealer penetration around the root canal were measured at 3, 5 and 8 mm from the apex.. No significant differences between groups were observed in fluid filtration rate nor in depth of calcein penetration. Sealer penetration depth and percentage into dentinal tubules were not significantly different between groups, except at 8-mm level in absence of smear layer.. Sealer penetration at 3- and 5-mm levels was not influenced by smear layer while it was significantly reduced at 8-mm level. Fluid filtration rate was not correlated either with depth of calcein penetration nor with sealer penetration into dentinal tubules.. The sealing ability of Topseal sealer is not affected by presence or absence of smear layer.

Topics: Dentin; Edetic Acid; Epoxy Resins; Fluorescent Dyes; Humans; In Vitro Techniques; Incisor; Materials Testing; Microscopy, Confocal; Rhodamines; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties

The purpose of this study was to assess the efficacy of different final irrigation activation methods in removing debris and smear layer in the apical, middle, and coronal portion of straight root canals.. Straight root canals of 58 freshly extracted mandibular premolars were used. Root canals were prepared to size 40.06. Irrigation was performed using 3% sodium hypochlorite. Samples were divided into four equal groups (n = 12) according to the irrigation activation techniques: (A) manual irrigation (MI), (B) EndoActivator (EA) (Dentsply Maillefer, Ballaigues, Switzerland), (C) sonic activation EDDY (EDDY; VDW, Munich, Germany), and (D) passive ultrasonic irrigation (PUI). Ten teeth served as negative controls. Roots were split longitudinally, and the canal walls were subjected to scanning electron microscopy. The presence of debris and smear layer at coronal, middle, and apical levels were evaluated using a 5-point scoring system and statistically analyzed using Kruskal-Wallis and chi-square tests.. Canal cleanliness decreased from coronal to apical (P = 0.035). Significantly more debris was removed with EA, EDDY, and PUI compared to MI (P < 0.001; total values), but no differences were observed in the different portions of the root canals (P > 0.05). Smear layer removal with PUI, EA, and EDDY was not significantly different (P > 0.05), but only EDDY and PUI were superior to MI (P < 0.01).. All activation methods created nearly debris-free canal walls and were superior compared to manual irrigation (P < 0.001). EDDY and PUI also showed significantly better smear layer scores compared to manual irrigation.. The sonic activation system EDDY performed equally as well as PUI, and both methods were significantly superior compared with manual irrigation in straight root canals with regard to debris and smear layer removal.

Topics: Bicuspid; Dental Pulp Cavity; Humans; In Vitro Techniques; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

Conventional manual irrigation with a syringe and needle remains widely accepted technique in the irrigation procedures. However, its flushing action has some limitations. Currently, several techniques and systems are available and reported to improve the insufficiency of syringe irrigation. The aim of this study was to evaluate the effectiveness of 7 different irrigation techniques compared to standard irrigation.. Straight roots from 80 extracted human maxillary central incisors were collected, and root canals were instrumented with K-files up to apical size 50. The teeth were randomly divided into 8 groups (n = 10), and final irrigation procedures were performed with 17% ethylenediaminetetraacetic acid and 5.25% NaOCl solutions using following irrigation agitation techniques: RinsEndo, EndoVac, Canal CleanMax, sonic, Canal Brush, NaviTip FX, manual dynamic irrigation, and conventional irrigation. The presence of debris and smear layer (SL) at coronal, middle, and apical thirds was evaluated by using a 5-grade scoring system with ×200 and ×1000 magnification, respectively.. Concerning debris removal, the MM 1500 sonic group reduced apical debris significantly better than the other groups tested (P < 0.05). There was no significant difference among the tested groups (P > 0.05) related SL removal in all levels.. MM 1500 scored best with debris removal; however, there was no significant reduction in the SL in apical third with any of the methods tested.

Topics: Dental Instruments; Dental Pulp Cavity; Edetic Acid; Humans; Incisor; Microscopy, Electron, Scanning; Needles; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

This ex vivo study evaluated the irrigation efficacy of a new apical negative pressure system (ANP) in canals with simulated immature teeth, by comparing it to EndoVac (EV) system in terms of smear layer (SL) removal and irrigation extrusion.. Three millimetres of the root end of 40 single canalled lower incisors were resected and decoronated to standardize root canal length. After instrumentation, the specimens were embedded in warm normal saline agar coloured with 1 % acid red and randomly divided into four groups; one control group and three experimental groups. Except in the control group where distilled water was used as irrigant using positive pressure irrigation needle, the canals were irrigated with 6 % NaOCl and 17 % EDTA using the intracanal negative pressure needle (iNP) system, the EV system or 27G open-ended needle under positive pressure (PP). NaOCl extrusion was determined by observing a discolouration of the agar surrounding the root. The SL was evaluated by observing scanning electron microscope images based on a four-level scoring system.. Two specimens with irrigant extrusion were observed in the iNP group, which was significantly different (logistic regression, p < 0.05) to EV and PP. There were no significant differences (Kruskall-Wallis test, p > 0.05) among the experimental groups in terms of SL removal, but all were significantly different to the control group.. Irrigation with the iNP could be a viable alternative to EV as an apical negative pressure irrigation technique especially while treating immature teeth.. ANP in canal cleanliness is recommended to be utilized in treating immature teeth where periapical tissues should be saved and stimulated. The iNP system might have the potential to avoid irrigant extrusion while cleaning the canal till the apical end.

Topics: Edetic Acid; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Pressure; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Suction; Therapeutic Irrigation

Topics: Cone-Beam Computed Tomography; Dental Pulp Cavity; Dentin; Equipment Design; Gutta-Percha; Humans; Imaging, Three-Dimensional; Microscopy; Radiography, Bitewing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Surface Properties

The objective of the presentin vitro study was to evaluate the canal wall smear layer removal capacity and mineral content distribution of root canal dentine after irrigation with QMix, 7% maleic acid (MA) and 17% ethylenediaminetetraacetic acid(EDTA).. Forty single-rooted teeth were subjected to root canal instrumentation and divided into four groups: [1] 7% MA+2.5% sodium hypochlorite (NaOCl), [2] 17% EDTA+ 2.5% NaOCl, [3] QMix+2.5% NaOCl and [4] 0.9% saline (negative control). After irrigation, the teeth were examined byscanning electron microscopy (SEM) to determine the presence or absence of smear layer. Formineral content assessment, 40 root-halves were divided into four groups and treated with 7% MA, QMix, 17% EDTA and saline. Mineral content was evaluated using SEM-energy dispersive X-ray analysis.. There was no significant difference between QMix, MA and EDTA in removal of smear layer from coronal and middle third of the canal spaces. In the apical third, MA performed better. Calcium was decreased more with QMix with no difference between MA and EDTA. Phosphorous was reduced more with MA and QMix than EDTA with no difference between MA and QMix. Similar result was observed with magnesium level. Carbon was reduced more with EDTA with no difference between QMix and MA. Oxygen was reduced significantly more with MA with no difference between QMix and EDTA.. 7% MA had superior smear layer removal ability compared with QMix and 17% EDTA. Calcium level was decreased more with QMix while phosphorus level was decreased more with 7% MA and QMix respectively.. The present study highlights the effect of newer chelating agentson smear layer removal and decalcification of root canal dentine, which is required for disinfection of the root canal space and maintenance of the structural integrity of the teeth.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Maleates; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The purpose of the study presented here was to compare the influence of root canal taper on the efficacy of irrigants and chelating agents in smear layer removal. Eighty mesial roots of molar teeth were selected and prepared with rotary instruments. In group A, file 30/0.02 and in group B, file 30/0.4 were placed at working length and the smear layer was removed. In groups C and D, root canal preparation was the same as in groups A and B, respectively, except that the smear layer was not removed. The amount of the smear layer was quantified using a scanning electron microscope. Greater smear layer was detected in the apical portion of each group, whereas no significant difference was detected between groups in other portions. No statistical difference was found between canals with different tapers.

Topics: Chelating Agents; Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Tooth Apex

The effect of smear layer and debris on the success rate of endodontic treatment has not yet been definitely determined. So the present study was aimed to evaluate the amount of smear layer and debris on the canal walls prepared with a combination of hand and rotary ProTaper technique using NaOCl and ethylenediaminetetraacetic acid (EDTA) alternately as root canal irrigants using scanning electron microscope (SEM).. Eighty intact freshly extracted human permanent mandibular premolar teeth were collected and randomly divided equally into four groups. In group I canals were prepared with hand K-Flexofiles; group II with rotary ProTaper instruments; group III with rotary ProTaper instruments and final instrumentation was done with hand K-Flexofile; group IV with rotary ProTaper instruments and final instrumentation was done with RC-Prep and irrigated with 1 mL of normal saline. In all groups canals were irrigated using NaOCl and EDTA alternately. After instrumentation, the teeth were prepared for SEM examination using five-score indices for debris and smear layer at coronal, middle, and apical third levels. Statistical analysis was performed using chi-square test (p < 0.05) and Kruskal-Wallis test (p < 0.05).. Statistically significant difference was observed between the groups in cleaning the apical third. Groups I and III showed better canal cleanliness compared to group II. The use of EDTA and NaOCl in group III was more effective in removing debris and smear layer compared to EDTA and normal saline in group IV. Regardless of the instrumentation technique employed and the irrigant used, the cleaning ability decreased in the apical third, resulting in higher debris and smear layer scores compared to coronal and middle third levels.. None of the instrumentation techniques in the present study could completely eliminate the smear layer and debris from the canal walls. Instrumentation of the canals with hand files after automated rotary preparation could result in cleaner canal walls.. Alternate irrigation with NaOCl and EDTA is effective in the removal of debris and smear layer in the coronal and middle level, but the effectiveness in the apical third is less.

Topics: Bicuspid; Dental Instruments; Edetic Acid; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The aim of this study was to evaluate the influence of the smear layer on the antimicrobial activity of a 2.5% sodium hypochlorite (NaOCl)/9% etidronic acid (HEBP) irrigating solution against bacteria growing inside dentin tubules.. Dentin tubules were infected with Enterococcus faecalis by centrifugation. After 5 days of incubation, the smear layer had formed in half of the samples, which were then treated with 2.5% NaOCl either alone or combined with 9% HEBP for 3 minutes. The percentage of dead cells in infected dentinal tubules was measured using confocal laser scanning microscopy and the live/dead technique. The smear layer on the surface of the root canal wall was also observed by scanning electron microscopy. Results of the percentage of dead cells were compared using parametric tests after subjecting data to the normalized Anscombe transformation. The level of significance was P < .05.. In the absence of the smear layer, 2.5% NaOCl alone and combined with 9% HEBP showed high antimicrobial activity without significant differences between the 2. The smear layer reduced the antimicrobial activity of 2.5% NaOCl significantly, whereas the solution with HEBP was not affected. No dentin tubules free of the smear layer were obtained in the 2.5% NaOCl group. In the case of 2.5% NaOCl/9% HEBP, 95.40% ± 3.63% of dentin tubules were cleaned.. The presence of the smear layer reduced the antimicrobial activity of 2.5% NaOCl. The combination of 2.5% NaOCl/9% HEBP exerted antimicrobial activity that was not reduced by the smear layer.

Topics: Anti-Infective Agents; Bacteria; Bicuspid; Dental Caries; Dental Pulp Cavity; Dentin; Enterococcus faecalis; Etidronic Acid; Humans; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

Cavitation and agitation generated by lasers in fluid-filled root canals create fluid movement and shear stresses along the root canals walls, enhancing removal of the smear layer and biofilm. When used with sodium hypochlorite and EDTA, laser activation of aqueous fluids can increase the efficiency of debridement and disinfection of root canals. However, the use of forward-firing laser fibers with such solutions poses a risk of driving fluid past the root apex, which could cause postoperative complications. The purpose of this study was to evaluate the mechanism of fluid agitation caused by a novel honeycomb tip. Glass capillary tubes filled with distilled water were used to replicate single-tooth root canals. A 980 nm pulsed diode laser was used with 200 μm diameter plain tips, tube-etched conical tips, and honeycomb tips. To record fluid movements, the tubes were backlit and imaged using a digital camera attached to a microscope. The honeycomb tips generated agitation with fluid movement directed onto the walls, while both the conventional plain fibers and the conical tips created fluid movement largely in a forward direction. The use of honeycomb tips alters the pattern of fluid agitation, and this laterally directed effect might lower the risk of fluid extrusion beyond the apex.

Topics: Dental Pulp Cavity; Endodontics; Humans; Laser Therapy; Lasers, Semiconductor; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To evaluate the effectiveness of isopropyl alcohol, saline or distilled water to prevent the precipitate formed between sodium hypochlorite (NaOCl) and chlorhexidine (CHX) and its effect on the bond strength of an epoxy-based sealer in radicular dentine.. The root canals of 50 extracted human canines (n = 10) were instrumented. In G1, root canals were irrigated with 17% EDTA and 2.5% NaOCl; G2, as G1, except that 2% CHX was used as the final irrigant. In the other groups, intermediate flushes with isopropyl alcohol (G3), saline (G4) or distilled water (G5) were used between NaOCl and CHX. The specimens were submitted to SEM analysis to evaluate the presence of debris and smear layer, in the apical and cervical segments. In sequence, fifty extracted human canines were distributed into five groups (n = 10), similar to the SEM study. After root filling, the roots were sectioned transversally to obtain dentine slices, in the cervical, middle and apical thirds. The root filling was submitted to a push-out bond strength test using an electromechanical testing machine. Statistical analysis was performed using Kruskal-Wallis and Dunn's tests (α = 5%).. All groups had similar amounts of residue precipitated on the canal walls (P > 0.05). The push-out bond strength values were similar for all groups, independently of the root third evaluated (P > 0.05).. Isopropyl alcohol, saline and distilled water failed to prevent the precipitation of residues on canal walls following the use of NaOCl and CHX. The residues did not interfere with the push-out bond strength of the root filling.

Topics: 2-Propanol; Chemical Precipitation; Chlorhexidine; Cuspid; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Epoxy Resins; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Water

We evaluated and compared the effects of different NiTi rotary systems--ProTaper Next and New One Shape--on the volume of dentin removed, canal transportation, and canal curvature in extracted human teeth using CBCT scanning with different voxel sizes.. Fifty extracted human maxillary first molars with mesiobuccal canal curvature (25-35°) were used. Specimens were instrumented with the ProTaper Next or New One Shape. Pre- and post-instrumentation scans were performed to compare transportation at the levels of 2, 5, and 8 mm and volumes with two different voxel sizes (0.125-and 0.100-mm(3)) using 3D CBCT images. This study evaluated and compare the volume of dentin removed, canal transportation, and canal curvature. Differences according to instrumentation and voxel sizes were assessed using the Mann-Whitney U-test and the Wilcoxon signed-rank test.. Significant differences were found between apical and coronal levels for both systems (p < 0.05) in canal transportation. In comparing the systems, similar values were found at each level, without significant difference (p > 0.05) in terms of canal curvature and volume. Voxel sizes did not affect the measurements on canal volume, curvature or transportation; no significant difference was found between the 0.100- and 0.125-mm(3) voxel sizes (p > 0.05).. Both instrumentation systems produced similar canal transportation and volume changes. The two voxel resolutions also showed similar results, however a 0.125-mm(3) voxel size can be recommend for a flat panel CBCT scanner with lower exposure dose.

Topics: Cone-Beam Computed Tomography; Dental Alloys; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Materials Testing; Molar; Nickel; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Titanium; Tooth Apex

The objective of this study was to evaluate the efficacy of passive ultrasonic irrigation (PUI) with 17% EDTA and 1% NaOCl solutions on smear layer removal.. Root canal preparations of 32 human teeth were performed with the ProTaper system. Next, they were longitudinally fractured to permit quantitation of smear layer creation from the cervical, middle, and apical thirds of the roots by using scanning electron microscopy. After reassembling the fractured tooth halves, they were divided into 4 groups according to different final irrigation protocols: group1, EDTA + NaOCl; group 2, EDTA with PUI + NaOCl; group 3, EDTA + NaOCl with PUI; and group 4, EDTA + NaOCl, both with PUI. After irrigation, the tooth halves were separated to permit imaging the same areas by scanning electron microscopy, and a percentage of opened dentinal tubules in irrigated areas as a percent of the total area was obtained. The results were submitted to Kruskal-Wallis, analysis of variance, and Bonferroni tests (α = 0.05).. The cervical third of the samples from all groups showed higher percentage of smear layer removal and open dentinal tubule areas, followed by the middle and apical thirds. Among the irrigation groups, there were statistically significant differences in cervical third between group 2 and group 4 samples, with the highest and lowest percentage of smear layer removal, respectively.. PUI by using 1% NaOCl and ultrasonic tip placed within 1 mm of the apical foramen did not show higher efficacy in smear layer removal compared with conventional irrigation.

Topics: Analysis of Variance; Edetic Acid; Humans; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth; Ultrasonic Therapy

This study aimed to evaluate, by means of scanning electron microscopy (SEM), the cleaning of flattened root canals, varying irrigation/aspiration protocols during biomechanical preparation. Thirdy human mandibular incisors were distributed into three groups (n = 10) according to the aspiration/irrigation protocols: conventional, conventional + brush, and apical negative pressure irrigation. Irrigation procedure was performed with 5 mL of 1% NaOCl at each change of instrument; final irrigation was conducted with 17% EDTA for 5 min. After biomechanical preparation, the roots were sectioned and prepared for SEM analysis. The images obtained were evaluated under 35× and 1,000× magnification by three calibrated examiners, following a double-blind design. All data were analyzed using Kruskal-Wallis and Dunn's post hoc tests (α = 0.05). Canals wherein the conventional method and apical negative pressure irrigation were employed revealed less debris, statistically different from the conventional + brush group (p < 0.05). Regarding the presence of smears, apical negative pressure irrigation was more effective in cleaning, showing lowest scores (p < 0.05), compared with the other tested protocols. Comparing each root canal third revealed that the apical portion was difficult to clean as all the tested protocols showed similar high scores (p > 0.05), both for the presence of debris and smear layer. In conclusion, although none of the studied irrigation/aspiration protocols have completely cleaned flattened root canals, apical negative pressure irrigation was more effective in smear layer removal, whereas the conventional + brush protocol was the least effective in removing the debris and smear layer.

Topics: Debridement; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Humans; Microscopy, Electron, Scanning; Reproducibility of Results; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties; Time Factors; Treatment Outcome

The aim of this study was to determine the root canal area before and after the instrumentation 1 mm short of the apical foramen by clinical and cone beam computed tomography (CBCT) methods, and to evaluate the cleanliness of the apical region in mesiodistal flattened teeth by using optical microscopy.. Forty-two human single-canal mandibular incisors were instrumented using the Free Tip Preparation technique up to three, four or five instruments from the initial. Cone beam computed tomography scans were acquired of the samples before and after root canal preparation (RCP). Irrigation was performed by conventional or hydrodynamic means, using 2.5% sodium hypochlorite. The samples were prepared for observation under an optical microscope. Images were digitally obtained, analyzed and the results were submitted to statistical analysis (two-way ANOVA complemented by Bonferroni's post-test).. There was no significant difference between the studied anatomical areas with both CBCT and clinical methods. There were no differences between irrigation methods. It was verified differences between instrumentation techniques. Instrumentation with four instruments from the initial instrument determined a significant increase in the contact area when compared to preparation with three instruments, but RCP with 5 instruments did not result in a better cleanliness.. The analysis with CBCT was not capable to determine the precise shape of surgical apical area comparing to the clinical method.. Both the conventional and hydrodynamic irrigation techniques were not able to promote root canals debris-free. The instruments action in root canal walls was proportional to the number of instruments used from the initial apical instrument.

Topics: Cone-Beam Computed Tomography; Dental Alloys; Dental Pulp Cavity; Dentin; Equipment Design; Humans; Incisor; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Surface Properties; Tooth Apex

The purpose of this study was to investigate the smear layer removal and erosive capacity of various irrigation solutions with sequential use of NaOCl on instrumented root canal walls.. The root canals of single-rooted teeth were instrumented with ProTaper rotary instrument. Then, the teeth were randomly divided into five experimental groups. The root canals were irrigated with one of the following solutions (5 mL/1 min): 5% EDTA, 5% boric acid (BA), a mixture of BA and CA, 2.5% citric acid (CA) and 5% Desy Clean. After irrigating with 2.5% NaOCl and distilled water, the roots were split into two halves and each half was prepared for SEM examination. Representative photographs were taken from each third at x500 and x1000 magnifications. Double blind scoring was performed by two calibrated observers for smear layer and erosion. The scores were statistically analyzed using Kruskal-Wallis, Dunn's post hoc and Spearman's correlation tests (p = 0.05).. There were statistically significant differences among the solutions by means of smear layer and erosion (p < 0.05). While 2.5% CA solution was the most effective solution in removal of smear layer, it was also the most erosive solution (p < 0.05). 5% Desy Clean removed smear layer effectively and caused less erosion. There was a negative, but statistically significant correlation between presence of smear layer and erosion (r = -0.684; p < 0.0001).. Desy Clean can be a promising agent as an irrigation solution with optimal smear layer removal capacity and less erosive effects.

Topics: Acetic Acid; Boric Acids; Citric Acid; Dental Pulp Cavity; Dentin; Drug Combinations; Edetic Acid; Humans; Hydrogen Peroxide; In Vitro Techniques; Materials Testing; Microscopy, Electron, Scanning; Photography; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Benzoate; Sodium Hypochlorite; Sorbic Acid; Tooth Erosion

To compare the effect of passive ultrasonic irrigation with manual dynamic irrigation on smear layer removal from root canals using a closed apex in vitro model.. The root canals of 45 freshly-extracted human single-rooted mandibular premolar teeth were prepared by the Pro-Taper rotary system to an apical preparation of F4 size. Prepared teeth were randomly divided into three groups; two experimental groups and one control group (n = 15) on the basis of the type of activation of final irrigation as follows: (a) Group A, 3% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA), no activation received; (b) Group B, 3% NaOCl and 17% EDTA, ultrasonic activation with a small file; and (c) Group C, 3% NaOCl and 17% EDTA, manual activation with a master gutta-percha point. The prepared teeth were decoronated and split into two halves longitudinally, and observed under a scanning electron microscope to assess the removal of the smear layer.. In the apical-third region, the mean smear scores for groups B and C were significantly less than those of Group A (control group) (P < 0.05).. Both activation techniques are important adjuncts in removing the smear layer, with manual dynamic activation being a simpler, safer, and more cost-effective technique.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Needles; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Tooth Apex; Ultrasonics

To investigate the effect of QMix irrigant compared with several other irrigating solutions on the bond strength of glass fibre posts to root dentine and on smear layer removal after post space preparation.. One hundred and fifty single-rooted teeth were used. The specimens were divided into six groups in each test according to the irrigation regimen used: group 1, distilled water; group 2, 5.25% sodium hypochlorite (NaOCl); group 3, 2% chlorhexidine digluconate (CHX); group 4, 17% ethylenediaminetetraacetic acid (EDTA); group 5, 17% EDTA followed by 2% CHX; and group 6, QMix. Dual-cure self-adhesive resin cement (i CEM; Heraeus Kulzer, Hanau, Germany) was used for testing the adhesion of glass fibre post (Reblida; VOCO, Cuxhaven, Germany) to root dentine using a micropush-out test. Debonding specimens were examined with a scanning electron microscope. Scanning electron microscopy was also used to examine and score the treated specimens for debris removal and dentinal tubule opening. Micropush-out data were analysed using anova and Tukey's test. Debris and dentinal tubule opening scores were analysed with the Kruskal-Wallis and Mann-Whitney U-tests.. QMix and 17% EDTA/2% CHX demonstrated the highest mean bond strength values in all root levels amongst the groups. Most failure modes were adhesive type of failures between post and luting material (42.6%). QMix, 17% EDTA and 17% EDTA/2% CHX performed significantly better than the other groups on smear layer removal and dentinal tubule opening.. QMix is an effective irrigant that can remove smear layer, open dentinal tubules and simplify the irrigation protocol, without compromising the bonding strength of glass fibre posts cemented with a self-adhesive resin cement to root dentine.

Topics: Adhesiveness; Biguanides; Chlorhexidine; Dental Bonding; Dental Stress Analysis; Dentin; Edetic Acid; Glass; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Polymers; Post and Core Technique; Resin Cements; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Water

This study aimed to investigate deproteinizing effect of sodium-hypochlorite (NaOCl) and mild acidic hypochlorous-acid (HOCl) pretreatment on smear layer-covered dentine and to evaluate their effects on morphological characteristics of resin-dentine interface with self-etch adhesive.. Human coronal-dentine discs with standardized smear layer were pretreated with 6% NaOCl or 50ppm HOCl for 15s or 30s. Their deproteinizing effects at the treated smear layer-covered dentine surfaces were determined by the measurement of amide:phosphate ratio using ATR-FTIR analysis. In addition, using TEM, micromorphological alterations of hybridized complex and nanoleakage expression were evaluated at the interface of a self-etch adhesive (Clearfil SE Bond) to the pretreated dentine surface with or without subsequent application of a reducing agent (p-Toluenesulfinic acid salt; Accel(®)).. Both pretreatments of NaOCl and HOCl significantly reduced the amide:phosphate ratio as compared with the no-pretreated group (p<0.05), coincident with the elimination of the hybridized smear layer on their bonded interfaces. Nanoleakage within the hybrid layer was found in the no-pretreated and NaOCl-pretreated groups, whereas the subsequent reducing agent application changed the reticular nanoleakage to spotted type. HOCl-pretreated groups showed less nanoleakage expression in a spotted pattern, regardless of reducing agent application.. NaOCl and HOCl solutions could remove the organic component on the smear layer-covered dentine, which could eliminate the hybridized smear layer created by self-etch adhesive, leading to the reduction of nanoleakage expression within hybrid layer.. Smear layer deproteinizing could modify dentine surface, giving an appropriate substrate for bonding to self-etch adhesive system.

Topics: Amides; Collagen; Composite Resins; Dental Bonding; Dental Leakage; Dental Materials; Dentin; Humans; Hypochlorous Acid; Materials Testing; Microscopy, Electron, Transmission; Phosphates; Random Allocation; Reducing Agents; Resin Cements; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Spectroscopy, Fourier Transform Infrared; Surface Properties; Time Factors; Toluene

The accumulation of debris occurs after root canal preparation procedures specifically in fins, isthmus, irregularities, and ramifications. The aim of this study was to present a step-by-step description of a new method used to longitudinally identify, measure, and 3-dimensionally map the accumulation of hard-tissue debris inside the root canal after biomechanical preparation using free software for image processing and analysis.. Three mandibular molars presenting the mesial root with a large isthmus width and a type II Vertucci's canal configuration were selected and scanned. The specimens were assigned to 1 of 3 experimental approaches: (1) 5.25% sodium hypochlorite + 17% EDTA, (2) bidistilled water, and (3) no irrigation. After root canal preparation, high-resolution scans of the teeth were accomplished, and free software packages were used to register and quantify the amount of accumulated hard-tissue debris in either canal space or isthmus areas.. Canal preparation without irrigation resulted in 34.6% of its volume filled with hard-tissue debris, whereas the use of bidistilled water or NaOCl followed by EDTA showed a reduction in the percentage volume of debris to 16% and 11.3%, respectively. The closer the distance to the isthmus area was the larger the amount of accumulated debris regardless of the irrigating protocol used.. Through the present method, it was possible to calculate the volume of hard-tissue debris in the isthmuses and in the root canal space. Free-software packages used for image reconstruction, registering, and analysis have shown to be promising for end-user application.

Topics: Anatomy, Cross-Sectional; Dental Alloys; Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Molar; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Software; Titanium; Water; X-Ray Microtomography

Root canal irrigation carries a risk of extrusion of irrigant into the periapical tissues which can be associated with pain, swelling, and tissue damage. Studies have shown less extrusion with sonic or apical negative pressure devices compared with syringe and side-port needle or passive ultrasonic irrigation with continuous irrigant flow. This study aimed to evaluate the effectiveness of the EndoVac irrigation system, regarding 1) debris removal and 2) the control of apically extruded irrigating solution.. Fifty extracted human single-rooted teeth were used in this study. The teeth were then randomly divided into three experimental groups according to the type of irrigation used and one control group. In group 1, irrigation was performed using the EndoVac irrigation system. In group 2, irrigation was performed using a 30-gauge, tip-vented irrigation needle. In group 3, irrigation was performed using a 30-gauge, side-vented irrigation needle. The control group received instrumentation with no irrigation to serve as a control for cleaning efficiency. Root canal instrumentation was performed using the Profile NiTi rotary system with a crown-down technique. All of the experimental teeth were irrigated with the same amount of 5.25% sodium hypochlorite. The amount of extruded irrigating solution was then measured by subtracting the post-instrumentation weight from the pre-instrumentation weight using an electronic balance. The cleanliness of debris removal was evaluated using scanning electron microscopy.. EndoVac irrigation had the least amount of extrusion followed by the side-vented and tip-vented method. The difference between the groups was statistically significant (P <0.01). As for the cleaning results, the debris collection in the EndoVac and tip-vented groups was the least in the apical third. In the control and the side-vented groups, the debris was the greatest in the apical third, but this difference was not significant among the three experimental groups.. The EndoVac irrigation system extruded significantly less irrigant solution than either needle irrigation system. Debris collection was the least in the apical third for the EndoVac irrigation system. No significant difference was found in the cleaning efficiency among the three irrigation systems.

Topics: Debridement; Dental Pulp Cavity; Equipment Design; Humans; Microscopy, Electron, Scanning; Needles; Periapical Tissue; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Therapeutic Irrigation; Tooth Apex; Vacuum

The aim of this study was to compare by scanning electron microscopy the presence of smear layer and debris on root canal walls after preparation with the single-file system WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) versus the rotary ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) under 2 final irrigant regimens.. Forty freshly extracted single-rooted human teeth were randomly divided into 4 groups (n = 10). The ProTaper and ProTaper and rotary CanalBrush (Coltène Whaledent GmbH+ Co KG, Langenau, Germany) groups were instrumented with the ProTaper system. Groups WaveOne and WaveOne and rotary CanalBrush were instrumented with the WaveOne system. The irrigant in all groups was 2 mL 5.25% sodium hypochlorite (NaOCl) solution, whereas the final irrigation after preparation in the ProTaper and WaveOne groups was 1 mL Smear Clear solution (Sybron Endo, Orange, CA) and then 5.25% NaOCl applied with a plastic syringe, and in the ProTaper and rotary CanalBrush and WaveOne and rotary CanalBrush groups, it was 1 mL Smear Clear solution and then 5.25% NaOCl (rotary CanalBrush agitation). Roots were processed for scanning electron microscopic examination for debris and smear layer scoring. Data were statistically analyzed.. All groups showed more efficient smear layer and debris removal coronally than in the middle and apical regions, whereas the mean total debris score and the mean smear layer score in all groups were less in the WaveOne and rotary CanalBrush groups than the ProTaper and rotary CanalBrush and the WaveOne and ProTaper groups.. Using the rotary CanalBrush in canals prepared with WaveOne produced the cleanest canal walls, and the WaveOne system gave superior results compared with the ProTaper system.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex; Treatment Outcome

This study was designed to quantitatively evaluate the amount of apically extruded debris by the Self-Adjusting-File system (SAF; ReDent-Nova, Ra'anana, Israel). Hand and rotary instruments were used as references for comparison.. Sixty mesial roots of mandibular molars were randomly assigned to 3 groups (n = 20). The root canals were instrumented with hand files using a crown-down technique. The ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) and SAF systems were used according to the manufacturers' instructions. Sodium hypochlorite was used as an irrigant, and the apically extruded debris was collected in preweighted glass vials and dried afterward. The mean weight of debris was assessed with a microbalance and statistically analyzed using 1-way analysis of variance and the post hoc Tukey multiple comparison test.. Hand file instrumentation produced significantly more debris compared with the ProTaper and SAF systems (P < .05). The ProTaper system produced significantly more debris compared with the SAF system (P < .05).. Under the conditions of this study, all systems caused apical debris extrusion. SAF instrumentation was associated with less debris extrusion compared with the use of hand and rotary files.

Topics: Dental Alloys; Dental Pulp Cavity; Equipment Design; Humans; Molar; Nickel; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Titanium; Tooth Apex

Laser-activated irrigation to remove organic debris from canal isthmuses was investigated using x-ray microfocus computed tomographic imaging.. A total of 14 extracted human mandibular molars were used. The mesial canals were prepared using a standardized instrumentation protocol. Two groups (n = 7) underwent final irrigation using either standard needle irrigation (SNI) or photon-induced photoacoustic streaming (PIPS). After enlarging canals to 30/.06, canal volumes were reconstructed from micro-computed tomographic scans before and after irrigation to assess removal of organic tissue and inorganic debris by quantitative analysis of the superimposed volumes. Comparisons of the volumes were made using 2-way analysis of variance and Tukey method, with statistical differences considered significant at the alpha = 0.05 level.. Debris removal and an increase in root canal system volume for the laser-activated PIPS group was more significant (P < .001) than for the SNI group (P = .04). Irrigation using PIPS increased the canal volume and eliminated debris from the canal system 2.6 times greater than SNI.. Eliminating debris from complex canal spaces found in mandibular molars was achieved at a significantly greater level using laser-activated PIPS irrigation compared with SNI.

Topics: Dental Pulp Cavity; Humans; Lasers, Solid-State; Needles; Photoacoustic Techniques; Pilot Projects; Pulpotomy; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; X-Ray Microtomography

Topics: Cracked Tooth Syndrome; Decision Making; Dental Leakage; Dental Pulp Calcification; Dental Pulp Cavity; Dental Pulp Diseases; Edetic Acid; Esthetics, Dental; Humans; Patient Care Planning; Patient Care Team; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Tooth Root

The aim of this study was to evaluate whether or not different final irrigation activation techniques affect the bond strength of an epoxy resin-based endodontic sealer (AH Plus; Dentsply DeTrey, Konstanz, Germany) to the root canal walls of different root thirds.. Eighty single-rooted human mandibular premolars were prepared by using the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) to size F4, and a final irrigation regimen using 3% sodium hypochlorite and 17% EDTA was performed. The specimens were randomly divided into 4 groups (n = 20) according to the final irrigation activation technique used as follows: no activation (control), manual dynamic activation (MDA), CanalBrush (Coltene Whaledent, Altststten, Switzerland) activation, and ultrasonic activation. Five specimens from each group were prepared for scanning electron microscopic observation to assess the smear layer removal after the final irrigation procedures. All remaining roots were then obturated with gutta-percha and AH Plus sealer. A push-out test was used to measure the bond strength between the root canal dentin and AH Plus sealer. The data obtained from the push-out test were analyzed using 2-way analysis of variance and Tukey post hoc tests.. The bond strength values mostly decreased in the coronoapical direction (P < .001). In the coronal and middle thirds, ultrasonic activiation showed a higher bond strength than other groups (P < .05). In the apical third, MDA displayed the highest bond strength to root dentin (P < .05). The majority of specimens exhibited cohesive failures.. The bond strength of AH Plus sealer to root canal dentin may improve with ultrasonic activation in the coronal and middle thirds and MDA in the apical third.

Topics: Dental Bonding; Dental Pulp Cavity; Dentin; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Microscopy, Electron, Scanning; Random Allocation; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Therapeutic Irrigation; Tooth Apex; Ultrasonic Waves

The effects of different EndoActivator® (EA) sonic activation protocols on root canal debridement efficacy were examined.. Root canals in 48 single-rooted teeth were instrumented, irrigated initially with NaOCl and divided into 6 groups (N=8) based on the application time of QMix (antimicrobial calcium-chelating irrigant), and the time and sequence of EA irrigant activation - Positive Control: 90s QMix; Negative Control: 90s saline; Group 1A: 15s QMix+15s QMix with EA-activation; Group 1B: 30s QMix+30s of QMix with EA-activation; Group 2A: 15s QMix with EA-activation+15s QMix; Group 2B: 30s QMix with EA-activation+30s QMix. Split roots were examined with scanning electron microscopy for assignment of smear and debris scores in locations along the coronal, middle and apical thirds of the canals. The overall cleanliness of pooled canal locations in the Positive Control and the 4 experimental groups were compared with chi-square tests.. Significant differences were detected among the 5 groups (P<0.001). Post hoc pairwise comparisons indicated that the overall canal cleanliness was in the order (from best to worst): 1B=2B>2A>1A>Positive Control. Completely clean canals could not be achieved due to the absence of continuous irrigant flow for EA to clear intraradicular debris.. Irrespective of the sonic activation sequence, irrigant activation for 30s during a 60-s period of QMix application appears to maximise the smear layer and debris removal potential of the EndoActivator® system.. Sonic activation of root canal irrigants produces cleaner root canals and reduces the time required for final delivery of a canal wall smear later-removing irrigant when compared to the use of needle irrigation alone.

Topics: Biguanides; Calcium Chelating Agents; Dental Pulp Cavity; Dentin; Humans; Materials Testing; Microscopy, Electron, Scanning; Polymers; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Therapeutic Irrigation; Time Factors; Tooth Apex

The purpose of the study was to determine the effect of apical clearing and apical foramen widening in reducing apical ramifications and bacterial load in the apical third of root canals. The mesio-buccal roots of 21 maxillary first molar teeth were inoculated with Enterococcus faecalis suspension using a sterile pipette. Samples were incubated at 37°C for 72 hrs and divided into 3 groups: Group A, control group (n=5), no preparation; Group B (n=8) conventional preparation alone; and Group C (n=8), apical clearing and foramen widening in addition to conventional preparation. Bacterial counts were semi-quantitatively analyzed pre- and post-preparation. Samples were demineralized with 5% nitric acid after injection of India ink. Cross sections were obtained at every 0.5 mm from the apex to 3 mm of the root using a vibratome and viewed under a stereomicroscope at 64×magnification to locate any debris or apical ramifications. The Kruskal-Wallis and Mann-Whitney U tests were used for the statistical analysis. A statistically significant difference was observed (p value 0.006) in the number of ramifications among the 3 groups. Group C had a lower average number of ramifications (1) than Group B (2.5) or A (4). The debris score was analyzed at each level (0.5-3 mm). A statistically significant difference was observed at 0.5 mm and 1 mm between Group A and C (p=0.0041) and Group B and C (p=0.0050), whereas no difference was found between Group A and B (p>0.05). These results indicate that there was less debris and fewer apical ramifications in Group C. The microbiological study revealed a lower number of colony forming units (10(2) -10(3)) in Group B or C than in Group A (>10(5)). These results suggest that apical widening and clearing facilitates removal of apical ramifications and bacterial load within root canals.

Topics: Adolescent; Adult; Anatomy, Cross-Sectional; Bacterial Load; Coloring Agents; Decalcification Technique; Dental Pulp Cavity; Enterococcus faecalis; Humans; Molar; Nitric Acid; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex; Young Adult

The development and maintenance of the sealing of the root canal system is the key to the success of root canal treatment. The resin-based adhesive material has the potential to reduce the microleakage of the root canal because of its adhesive properties and penetration into dentinal walls. Moreover, the irrigation protocols may have an influence on the adhesiveness of resin-based sealers to root dentin.. The objective of the present study was to evaluate the effect of different irrigant protocols on coronal bacterial microleakage of gutta-percha/AH Plus and Resilon/Real Seal Self-etch systems.. One hundred ninety pre-molars were used. The teeth were divided into 18 experimental groups according to the irrigation protocols and filling materials used. The protocols used were: distilled water; sodium hypochlorite (NaOCl)+eDTA; NaOCl+H3PO4; NaOCl+eDTA+chlorhexidine (CHX); NaOCl+H3PO4+CHX; CHX+eDTA; CHX+ H3PO4; CHX+eDTA+CHX and CHX+H3PO4+CHX. Gutta-percha/AH Plus or Resilon/Real Seal Se were used as root-filling materials. The coronal microleakage was evaluated for 90 days against Enterococcus faecalis. Data were statistically analyzed using Kaplan-Meier survival test, Kruskal-Wallis and Mann-Whitney tests.. No significant difference was verified in the groups using chlorhexidine or sodium hypochlorite during the chemo-mechanical preparation followed by eDTA or phosphoric acid for smear layer removal. The same results were found for filling materials. However, the statistical analyses revealed that a final flush with 2% chlorhexidine reduced significantly the coronal microleakage.. A final flush with 2% chlorhexidine after smear layer removal reduces coronal microleakage of teeth filled with gutta-percha/AH Plus or Resilon/Real Seal SE.

Topics: Adhesiveness; Chlorhexidine; Composite Resins; Dental Bonding; Dental Leakage; Dentin; Disinfectants; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Reproducibility of Results; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Therapeutic Irrigation; Time Factors; Water

The purpose of this study was to evaluate the canal isthmus debridement efficacy of a new modified EndoVac (Discus Dental, Culver City, CA) irrigation protocol in comparison with EndoVac, passive ultrasonic irrigation (PUI), and conventional needle irrigation in mesial roots of mandibular molars.. The mesial roots of 64 extracted mandibular molars mounted in resin using Kuttler's endodontic cube, sectioned at 2 and 4 mm from the working length, were randomly divided into 4 groups (n = 16): group 1: Max-I-Probe (Dentsply Tulsa Dental, York, PA), group 2: EndoVac (EVI), group 3: modified EndoVac, and group 4: PUI. The specimens were reassembled and instrumented. A standard irrigation protocol was used during cleaning and shaping and final irrigation with the 4 irrigation/agitation techniques. Images of the isthmus region were taken before and after cleaning and shaping and after final irrigation. The percentage reduction of debris in the isthmus region was calculated by using the software program Image J (v1.43; National Institutes of Health, Bethesda, MD). Intergroup analysis was performed using the Kruskal Wallis and Mann-Whitney U tests. Intragroup analysis was performed using Friedman and Wilcoxon signed rank tests. The level of significance was set at P < .05.. Intragroup analysis revealed a statistically significant difference in the percentage reduction of debris after cleaning and shaping and after final irrigation protocol in all the groups (P < .001). The final irrigation protocol produced significantly cleaner canal isthmuses in all the groups (P < .001). On intergroup analysis, the modified EVI group performed significantly better than the other groups. The EVI and PUI groups performed better than the Max-I-Probe group. There was no statistical significance between the EVI and PUI groups.. Canal isthmuses were significantly cleaner with the modified EndoVac irrigation technique when compared with the cleanliness seen with the other irrigation systems.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Image Processing, Computer-Assisted; Molar; Needles; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonic Therapy

To study the effect of the smear layer on the penetration of bacteria along different root canal fillings and to compare the sealing ability of new endodontic material Apexit plus as compared to Zinc Oxide Eugenol (ZOE) in primary teeth.. A total of 60 human root segments were instrumented for endodontic treatment. Half of the sample size was irrigated with normal saline and in other half 3% NaOCl, 3% H2O2 and 17% EDTA was used alternatively as irrigant during instrumentation. The roots were rinsed thoroughly with distilled water and sterilized by autoclaving for 20 min at 121 +/- 2 degrees C. Roots with and without smear layer were obturated with Apexit plus, Zinc oxide eugenol. Following storage in humid conditions at 37 degrees C for 2 days, the specimens were mounted into a bacterial leakage test model for 180 days.. At 180 days, there is statistically significant difference with a P value of < 0.05 among all groups except ZOE-smear and -nonsmear. In the presence of smear layer Apexit plus demonstrated more leakage. No leakage was observed in ZOE groups. ZOE demonstrated better sealing ability than Apexit plus.. Removal of smear layer helps in better resistance to bacterial penetration along Apexit plus root canal fillings but no effect is seen along ZOE root canal fillings.

Topics: Calcium Hydroxide; Dental Bonding; Dental Leakage; Dental Pulp Cavity; Edetic Acid; Enterococcus faecalis; Humans; Humidity; Hydrogen Peroxide; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Temperature; Time Factors; Tooth, Deciduous; Zinc Oxide-Eugenol Cement

During chemomechanical instrumentation, several liquid or paste substances are used to ease the action of the files and to eliminate debris and the smear layer. The aim of this study was to evaluate whether the use of a paste containing EDTA during cleaning and shaping of the root canal helps to eliminate debris.. Twenty root canals in dog teeth were instrumented by a crown-down technique by using nickel-titanium rotary files. In 10 root canals (group A), sodium hypochlorite was used during instrumentation, followed by a final irrigation with 17% liquid EDTA. In another 10 canals (group B), sodium hypochlorite was again used as the irrigating solution, but Glyde File Prep paste was used with every instrument, and a final irrigation with EDTA was also carried out. Two additional teeth were used as positive and 2 as negative controls. The jaws were prepared for histologic evaluation.. In group A where Glyde was not used during cleaning and shaping, little or no debris was found in the apical third of the instrumented root canals; however; in group B in which Glyde File Prep paste was used during chemomechanical instrumentation, moderate to high accumulation of debris was observed in the apical third.. The use of Glyde File Prep paste during rotary mechanical instrumentation favors the accumulation of debris in the apical third of the root canals. Irrigation with NaOCl and a final flush with EDTA by means of a small-gauge needle with simultaneous aspiration led to less accumulation of debris than in the Glyde File Prep group (P < .05).

Topics: Animals; Dental Alloys; Dental Pulp Cavity; Dogs; Edetic Acid; Equipment Design; Male; Needles; Nickel; Ointments; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Solutions; Suction; Titanium; Tooth Apex

Efforts to improve the efficacy of smear layer removal by applying irrigant activation at the final irrigation or by elevating the temperature of the irrigant have been reported. However, the combination of such activation protocols with 60 °C 3% sodium hypochlorite (NaOCl) has seldom been mentioned. The aim of this study was to compare the efficacy in smear layer removal of four different irrigation techniques combined with 60 °C 3% NaOCl and 17% EDTA.. Fifty single-rooted teeth were randomly divided into five groups (n = 10) according to the irrigant agitation protocols used during chemomechanical preparation(Dentsply Maillefer, Ballaigues, Switzerland): a side-vented needle group, a ultrasonic irrigation (UI) group, a NaviTip FX group, an EndoActivator group, and a control group (no agitation). After each instrumentation, the root canals were irrigated with 1 mL of 3% NaOCl at 60 °C for 1 minute, and after the whole instrumentation, the root canals were rinsed with 1 mL of 17% EDTA for 1 minute. Both NaOCl and EDTA were activated with one of the five irrigation protocols. The efficacy of smear layer removal was scored at the apical, middle and coronal thirds. The Data were statistically analyzed using SAS version 9.2 for Windows (rank sum test for a randomised block design and ANOVA).. No significant differences among the NaviTip FX group, EndoActivator group and control groups, and each of these groups showed a lower score than that of UI group (P < 0.05). Within each group, all three thirds were ranked in the following order: coronal > middle > apical (P < 0.05). In the coronal third, the NaviTip FX group was better than UI group. In the middle and apical third, the differences were not significant among any of the groups.. Even without any activation, the combination of 60 °C 3% NaOCl and 17% EDTA could remove the smear layer effectively, similar to NaviTip FX or EndoActivator, and these three protocols were more effective than UI. However, regardless of different types of irrigation technique applied, complete removal of the smear layer was not achieved, particularly in the apical third.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Hot Temperature; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Tooth Apex; Treatment Outcome; Ultrasonics

This study sought to assess if the final rinse protocol interferes with the smear layer removal in the apical area of curved canals. Sixty-four extracted human mandibular molars with curved mesial roots were instrumented with rotary files and divided into six experimental groups for final rinse: 1EDTA (syringe irrigation with 1 mL of 17% ethylenediaminetetraacetic acid (EDTA) ), 5EDTA (syringe irrigation with 5 mL of 17% EDTA), 1EDTA-P (syringe irrigation with 1 mL of 17% EDTA + pumping with gutta-percha point), 5EDTA-P (syringe irrigation with 5 mL of 17% EDTA + pumping with gutta-percha point), 1EDTA-EA (syringe irrigation with 1 mL of 17% EDTA + EndoActivator) and 5EDTA-EA (syringe irrigation with 5 mL of 17% EDTA + EndoActivator). Final rinsing was carried out over 3 min. The specimens were split lengthwise and observed under a scanning electron microscope using a score criterion. Comparison among the groups showed statistically significant difference only between the 5EDTA-EA group and the other groups (Kruskal-Wallis and Dunn's post-hoc tests, P < 0.05). The combination of 5 mL of 17% EDTA and 3 mL of 2.5% sodium hypochlorite (NaOCl) with the EndoActivator removed smear layer from the apical area of curved root canals more effectively than the other protocols used.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Syringes; Therapeutic Irrigation; Time Factors; Tooth Apex

Laser enhancement of ethylenediaminetetraacetic acid with cetrimide (EDTAC) has previously been shown to increase removal of smear layer, for middle-infrared erbium lasers. This study evaluated the efficiency of EDTAC activation using a near-infrared-pulsed 940 nm laser delivered by plain fibre tips into 15% EDTAC or 3% hydrogen peroxide. Root canals in 4 groups of 10 single roots were prepared using rotary files, with controls for the presence and absence of smear layer. After laser treatment (80 mJ pulse(-1) , 50 Hz, 6 cycles of 10 s), roots were split and the apical, middle and coronal thirds of the canal were examined using scanning electron microscopy, with the area of dentine tubules determined by a validated quantitative image analysis method. Lasing EDTAC considerably improved smear layer removal, while lasing into peroxide gave minimal smear layer removal. The laser protocol used was more effective for smear layer removal than the 'gold standard' protocol using EDTAC with sodium hypochlorite (NaOCl). In addition, lasers may also provide a benefit through photothermal disinfection. Further research is needed to optimise irrigant activation protocols using near-infrared diode lasers of other wavelengths.

Topics: Cetrimonium; Cetrimonium Compounds; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Hydrogen Peroxide; Image Processing, Computer-Assisted; Lasers, Semiconductor; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

The aim of this study was to test the dentinal tubule penetration of AH26 (Dentsply DeTrey, Konstanz, Germany) and MTA Fillapex (Angelus, Londrina, PR, Brazil) in instrumented root canals obturated by using cold lateral compaction or warm vertical compaction techniques in either the presence or absence of the smear layer.. Forty-five extracted single-rooted human mandibular premolar teeth were used. The crowns were removed, and the root canals were instrumented by using the Self-Adjusting File (ReDent-Nova, Ra'anana, Israel) with continuous sodium hypochlorite (2.6%) irrigation. Final irrigation was either with 5% EDTA or with sodium hypochlorite. The canals were dried and obturated by using rhodamine B-labeled AH26 or MTA Fillapex in combination with the cold lateral compaction or the warm vertical compaction technique. After setting, the roots were sectioned horizontally at 4-, 8-, and 12-mm distances from the apical tip. On each section, sealer penetration in the dentinal tubules was measured by using confocal laser scanning microscopy.. Regardless of the usage of EDTA, MTA Fillapex, compared with AH26, was associated with greater sealer penetration when used with the cold lateral compaction technique, and, conversely, AH26, compared with MTA Fillapex, was associated with greater sealer penetration when used with the warm vertical compaction technique (P < .05). Removal of the smear layer increased the penetration depth of MTA Fillapex used with the cold lateral compaction technique (P < .05); however, it had no significant effect on the penetration depth of AH26.. Greater sealer penetration could be achieved with either the MTA Fillapex-cold lateral compaction combination or with the AH26-warm vertical compaction combination. Smear layer removal was critical for the penetration of MTA Fillapex; however, the same did not hold for AH26.

Topics: Aluminum Compounds; Calcium Compounds; Dental Pulp Cavity; Dentin; Drug Combinations; Edetic Acid; Epoxy Resins; Fluorescent Dyes; Humans; Materials Testing; Microscopy, Confocal; Microscopy, Electron, Scanning; Oxides; Random Allocation; Rhodamines; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silicates; Smear Layer; Sodium Hypochlorite; Temperature; Tooth Apex

The aim of this in vitro study was to compare the effectiveness of saline, 2.5% sodium hypochlorite, and 2% chlorhexidine, with or without passive ultrasonic irrigation (PUI), in debris removal from simulated canal irregularities within prepared root canals.. Ninety bovine lateral incisors were randomly divided into 3 main groups (n = 30) based on the irrigant and prepared with hand files attached to an oscillating handpiece (NSK, Tokyo, Japan) up to a size #80 K-file. Next, the teeth were split longitudinally, and a standardized groove was prepared into the apical third and filled with dentin debris. After the halves were reassembled, they were placed in a muffle. Each main group was randomly subdivided into 2 groups (n = 14) and was treated with different final irrigation protocols. In the sodium hypochlorite/PUI, chlorhexidine/PUI, and saline/PUI groups, the solution was ultrasonically activated 3 times for 20 seconds. In the remaining groups, PUI was not performed. Specimens were scored for debris removal and analyzed under a scanning electron microscope.. An association was observed between the score of debris removal and protocols using PUI (P < .05). No association was observed between the scores of debris removal and the irrigants (P = .87).. Final irrigation protocols that used PUI were more effective in removing debris from simulated canal irregularities into the apical third than those that did not use it.

Topics: Animals; Cattle; Chlorhexidine; Dental Pulp Cavity; Edetic Acid; Materials Testing; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Therapeutic Irrigation; Tooth Apex; Ultrasonic Therapy

Topics: Chlorhexidine; Dental Pulp Cavity; Edetic Acid; Equipment Design; Equipment Failure; Humans; Periapical Tissue; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics; Vibration

Cleaning and disinfection of the root canal system are some of the most important goals in endodontic therapy. The aim of this preliminary study is to assess the effectiveness of Er:YAG laser fiber in removing the smear layer produced during root canal walls instrumentation. Forty-eight single-rooted teeth were prepared with manual and rotary Ni-Ti instruments, in addition to 2.5% NaOCl irrigation. Samples were randomly subdivided into groups and treated with: three irradiations of 5 s each, with 300-μm Er:YAG endodontic fiber, 1 W and 2.5% NaOCl solution (A Group); two laser irradiations with 17% EDTA solution and 2.5% NaOCl solution (B Group); laser irradiation plus 17% EDTA solution and 2.5% NaOCl (C Group); only in the final wash of 17% EDTA (control group D). During laser treatment, temperature variations were analyzed by using thermocouple and thermal camera devices in order to test both deep and superficial temperatures. Each sample was finally observed by scanning electron microscope (SEM) at the coronal, medium, and apical thirds at ×500 magnification and blindly scored depending on the amount of smear layer. Statistical analysis of the results was conducted using the Kruskal-Wallis and Mann-Whitney test to determine the eventual significant differences between the quantity of smear layer in each group and between the groups at coronal, medium, and apical third: a p value <0.05 was considered significant. The thermal analysis realized by thermocouple with the used parameters demonstrated that laser endodontic fiber produces an average deep temperature increase of 3.5 ± 0.4 °C; analysis performed with a thermal camera showed an average superficial temperature increase of 1.3 ± 0.2 °C produced by laser endodontic fiber use. Deep and superficial temperatures fall immediately after irradiation possibly without causing structural damage or anatomical alteration inside the root canal and neither on periodontal tissues. SEM analysis showed that specimens of group B had the highest level of cleaning in every third, with a significant difference with groups D and A; group C samples showed a good percentage of cleaned tubules in apical and middle thirds, while group D teeth showed open dentinal tubules in coronal third, with a statistical difference with group A samples which were the worst cleaned. The Er:YAG fiber double irradiation with EDTA 17% and NaOCl 2.5% has been demonstrated to be effective in removing smear layer, even in the apical third which

Topics: Disinfection; Edetic Acid; Humans; Lasers, Solid-State; Microscopy, Electron, Scanning; Pulpitis; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Temperature; Tooth

Topics: Adult; Dental Alloys; Dental Pulp Cavity; Dental Pulp Exposure; Dentin; Equipment Design; Female; Humans; Male; Middle Aged; Nickel; Pulpitis; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Titanium; Tooth Apex; Tooth Fractures; Young Adult

This study evaluated the root canal seal achieved by irradiation with an erbium, chromium:yttrium-scandium-gallium-garnet laser, and the optimal output power to remove debris and the smear layer were determined. One hundred mandibular premolar teeth were prepared and divided into four groups. Group 1 was not lased but was irrigated with 5 mL of 5.25% NaOCl and 5 mL of 17% ethylenediaminetetraacetic acid. Group 2 was irradiated at a panel setting of 1 W, group 3 at 2 W and group 4 at 2.5 W, with a 50% water level and 48% air-cooling level. Root canals were obturated by cold lateral compaction, and apical microleakage was measured using a fluid filtration model. The remaining debris and smear layer were evaluated via scanning electron microscopy. Statistically significant differences were detected between groups. Irradiation at 1 and 2 W using an erbium, chromium:yttrium-scandium-gallium-garnet laser produced a seal superior to that of the other treatments.

Topics: Dental Leakage; Dental Pulp Cavity; Dentin; Edetic Acid; Gutta-Percha; Humans; Lasers, Solid-State; Low-Level Light Therapy; Microscopy, Electron, Scanning; Radiotherapy Dosage; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

The aim of this study was to evaluate the effect of different post-space treatments on the push-out bond strength and failure modes of glass fibre posts. Forty mandibular premolar roots were cut and endodontically treated. Post spaces were prepared and roots were divided into four groups. In group 1 distilled water irrigation (control), in group 2 2.25% NaOCl irrigation, in group 3 2.25% NaOCl + 17% EDTA irrigation were done and in group 4 diode laser was applied to the prepared post spaces. Scanning electron microscope (SEM) analysis was made for each group. Fibre posts were then luted with resin cement. Each root was prepared for push-out test. Data were statistically analysed with anova (P = 0.05). After push-out test, the failure modes were observed but not statistically analysed. There were statistically significant differences between Group 3 and Group 2 in both regions (P < 0.05), also in the middle region of Group 4 and Group 2 (P < 0.05). Cervical root segments showed higher bond strengths than middle ones in all groups (P < 0.05). The highest bond strength values were obtained from NaOCl/EDTA and the lowest bond strength values were obtained from NaOCl for both regions.

Topics: Bicuspid; Composite Resins; Dental Bonding; Dental Materials; Dental Prosthesis Design; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Edetic Acid; Glass; Humans; Lasers, Semiconductor; Low-Level Light Therapy; Microscopy, Electron, Scanning; Post and Core Technique; Resin Cements; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Surface Properties; Tooth, Nonvital

The aim of this study was to evaluate the influence of different irrigation protocols on resin-based sealer bond strength to dentin and the associated failure pattern.. One hundred eighty single-rooted premolars were used. Roots were divided into 18 groups according to the irrigation protocol used and instrumented using 5.25% NaOCl or 2% chlorhexidine (CHX) gel as chemical auxiliary substances and 17% EDTA or 37% phosphoric acid for smear layer removal. Finally, CHX solution was used as the final irrigant in some groups. Root canals were filled with either gutta-percha and AH Plus (Dentsply, Petropolis, RJ, Brazil) (GP/AH) or Resilon/Real Seal SE (SybronEndo, Orange, CA). Bond strength was measured by the push-out test. Additionally, failure patterns were classified as adhesive, cohesive, and mixed. Data were statistically analyzed by Kruskal-Wallis and Mann-Whitney U tests.. In the GP/AH groups, high bond strength values were obtained when NaOCl was associated with phosphoric acid with (6.9 ± 3.9) and without (7.4 ± 3.8) a final flush with CHX. However, when CHX gel was used, the association with EDTA with (7.5 ± 3.2) and without (6.0 ± 2.3) a final flush with CHX solution showed better results. The GP/AH groups mainly showed a cohesive failure pattern. Evaluation of Resilon/Real Seal SE showed that higher bond strength values were reached when CHX was associated with phosphoric acid with (5.2 ± 3.0) and without (4.2 ± 2.0) a final flush with CHX solution. The failure patterns were mainly adhesive.. Irrigation protocols influenced the bond strength of resin sealers to dentin.

Topics: Adhesiveness; Bicuspid; Chlorhexidine; Composite Resins; Dental Bonding; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Phosphoric Acids; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Therapeutic Irrigation; Tooth Apex

A flowable gel-type EDTA solution containing urea peroxide and polyacrylic acid was recently introduced into the endodontic market. However, its efficacy for removing the smear layer and inorganic debris remains unknown. This study was performed to investigate the relative efficacies of the flowable gel-type and liquid-type EDTA solutions for removal of the smear layer and inorganic debris. We also evaluated the effects of manual dynamic activation (MDA).. Wettability was evaluated by measuring the contact angle. The incidence of accidental extrusion of irrigant was determined. The effervescent effect was evaluated by mixing the solutions with sodium hypochlorite. The efficacies of the EDTA solutions at removing the smear layer and inorganic debris were evaluated by scanning electron microscopic examination.. The contact angles of the 2 EDTA solutions did not differ significantly throughout the experiment (P > .05). Accidental extrusion occurred 4 times for the liquid-type EDTA but never for the gel-type EDTA. The gel-type but not the liquid-type EDTA showed an effervescent effect. The EDTA/MDA treatment combinations did not produce significantly different smear layer scores (P > .05). However, the debris scores for the coronal and middle parts were significantly lower for the gel-type EDTA with MDA than for the liquid-type EDTA without MDA (P < .05).. Our results suggest that the newly introduced gel-type EDTA might be an acceptable irrigant for removing the smear layer and inorganic debris present on the root canal wall.

Topics: Acrylic Resins; Carbamide Peroxide; Dental Pulp Cavity; Dentin; Edetic Acid; Gels; Humans; Materials Testing; Microscopy, Electron, Scanning; Peroxides; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Solutions; Surface Properties; Tooth Apex; Urea; Wettability

The Er:YAG laser with photon-induced photoacoustic streaming (PIPS) technique was reported to be effective in root canal disinfection. This study attempted to further investigate the antibacterial efficacy and smear layer removal ability of PIPS in comparison with conventional syringe irrigation in vitro.. For antibacterial analysis, 48 single-rooted human teeth were prepared and inoculated with Enterococcus faecalis, and then divided into six groups of eight roots each. The colony-forming units (CFUs) per milliliter were determined after infection as the baseline. Then, the teeth were subjected to either PIPS plus 3% sodium hypochlorite (PIPS+NaOCl) or conventional syringe irrigation with 0.9% saline, 3% NaOCl, 17% ethylenediaminetetraacetic acid (EDTA), 0.2% chlorhexidine gluconate (CHX), or 3% NaOCl alternating with 17% EDTA. The reduction of CFUs in the individual group was determined. Additionally, scanning electron microscopy (SEM) examination of the canal walls for E. faecalis colonization was performed. For comparing the smear removal efficacy, another 48 single-rooted teeth, assigned to different groups as mentioned, were irrigated after mechanical instrumentation. The presence of a smear layer at different levels of the root canal was scored by SEM examination.. No significant differences were found in CFU reduction. No bacteria could be observed by SEM in the NaOCl, NaOCl+EDTA, and PIPS+NaOCl groups. The scores of smear layer of the NaOCl+EDTA and PIPS+NaOCl groups were significantly lower than those of the other groups in the coronal and middle third of the root canal. None of the methods can effectively remove smear layer in the apical third.. PIPS system supplied with NaOCl and conventional syringe irrigation with NaOCl+EDTA are comparable in their ability to remove E. faecalis and smear layer in single-rooted canals.

Topics: Bacterial Load; Chelating Agents; Chlorhexidine; Dental Pulp Cavity; Disinfection; Edetic Acid; Enterococcus faecalis; Humans; In Vitro Techniques; Low-Level Light Therapy; Microscopy, Electron, Scanning; Photoacoustic Techniques; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stem Cells; Therapeutic Irrigation

Endodontic success depends heavily on effective chemo-mechanical debridement of root canals through the use of instruments and irrigating solutions.. To compare the effectiveness of chamomile hydroalcoholic extract, Biopure™ mixture of tetracycline isomer, acid and detergent (MTAD) and 2.5 % sodium hypochlorite (NaOCl) on removal of the smear layer.. Randomised controlled trial.. Thirty extracted single-rooted, primary human teeth were allocated at random into three experimental groups of 10 teeth each. For each tooth, the canal was prepared using the step-back technique. During instrumentation, 2 ml of the irrigant was used for at least 10 s after each file and 10 ml as a final flush for 2 min for chamomile and NaOCL irrigants. Whereas for MTAD, an initial rinse with 1.3 % NaOCl for a cumulated period of 20 min, and use of MTAD as the final rinse for a period of 5 min was followed. Longitudinal grooves were made on root segments, then split into two halves with a chisel, stored in 2.5 % glutaraldehyde solution and fixed in ethanol series. Specimens were examined for the smear layer according to Hulsmann et al. (Int Endod J 35:668-679, 2002) criteria using a scanning electron microscope.. Kruskal-Wallis and Mann-Whitney U tests were used.. The most effective result in removal of smear layer occurred with the use of MTAD, followed by chamomile extract. The chamomile extract was found to be significantly more effective than 2.5 % NaOCl solution which had only minor effects.. The efficacy of chamomile to remove the smear layer was superior to 2.5 % NaOCl alone, but less effective than MTAD mixture.

Topics: Chamomile; Dental Pulp Cavity; Dentin; Detergents; Edetic Acid; Humans; Materials Testing; Matricaria; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium; Sodium Hypochlorite; Statistics, Nonparametric; Tetracycline; Tooth Apex

This study aimed to compare the effects of different irrigants on root dentine microhardness, erosion and smear layer removal. A total of 72 root dentine slices were divided into six groups, according to the final irrigants used: Group 1: 17% ethylenediamine tetra-acetic acid (EDTA) + 2.5% NaOCl, Group 2: 7% maleic acid (MA) + 2.5% sodium hypochloride (NaOCl), Group 3: 1.3% NaOCl + mixture of tetracycline, acid and detergent (MTAD), Group 4: Smear Clear + 2.5% NaOCl, Group 5: 5% NaOCl, Group 6: saline. Vickers microhardness values were measured before and after treatment. In total, 42 root-halves were prepared for scanning electron microscope to evaluate the amount of smear and erosion in the coronal, middle and apical thirds. Data were analysed using two-way anova, Duncan and two-proportion z-tests. Maleic acid showed the greatest reduction in dentine microhardness (P < 0.05), followed by EDTA and MTAD. EDTA, maleic acid, MTAD and Smear Clear removed smear layer efficiently in the coronal and middle thirds of root canal. However, in the apical region, maleic acid showed more efficient removal of the smear layer than the other irrigants (P < 0.05).

Topics: Citric Acid; Dental Pulp Cavity; Dentin; Doxycycline; Drug Combinations; Edetic Acid; Hardness; Humans; Maleates; Materials Testing; Microscopy, Electron, Scanning; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Tooth Apex; Tooth Erosion

This study aimed to evaluate the ability of a newly developed calcium-phosphate desensitizer in dentin permeability reduction and its integration with dentin surface before and after immersion in artificial saliva (AS) under two different dentin surface characteristics; with or without the collagen exposure.Humandentin discs treated by EDTA to expose collagen fibrils or EDTA/NaOCl to expose plain dentin surface were subjected to a calcium-phosphate desensitizer (Teethmate Desensitizer; TMD), while non-desensitizer treatment served as control. TMD application showed the occlusion in dentinal tubules and reduction in dentin permeability up to 92%, regardless of dentin surface characteristics. After AS immersion, permeability reduction percent (PR%) significantly increased in EDTA/NaOCl pretreatment (p<0.05). Newly-formed crystallites were observed on desensitizer treated dentin and EDTA/NaOCl pretreatment control group, whereas the crystallites did not exist on EDTA pretreatment control group. Ultrasonication revealed the integration of the calcium-phosphate rich layer of desensitizer on dentin surface after AS immersion.

Topics: Calcium Phosphates; Chelating Agents; Collagen; Crystallization; Dentin; Dentin Desensitizing Agents; Dentin Permeability; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Oxidants; Saliva, Artificial; Smear Layer; Sodium Hypochlorite; Ultrasonics

This study examined the effect of the smear layer on the antibacterial effect of different disinfecting solutions in infected dentinal tubules.. Cells of Enterococcus faecalis were forced into dentinal tubules according to a previously established protocol. After a 3-week incubation period of infected dentin blocks, a uniform smear layer was produced. Forty infected dentin specimens were prepared and subjected to 3 and 10 minutes of exposure to disinfecting solutions including sterile water, 2% and 6% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 17% EDTA, and QMiX (Dentsply Tulsa Dental, Tulsa, OK). The following combinations were also included: 2% NaOCl + 2% CHX, 2% NaOCl + QMiX, 6% NaOCl + QMiX, and 6% NaOCl + 17% EDTA + 2% CHX. Four other dentin specimens similarly infected but with no smear layer were subjected to 3 minutes of exposure to 2% CHX and 6% NaOCl for comparison. Confocal laser scanning microscopy and viability staining were used to analyze the proportions of dead and live bacteria inside the dentin.. In the presence of a smear layer, 10 minutes of exposure to QMiX, 2% NaOCl + QMiX, 6% NaOCl + QMiX, and 6% NaOCl + 17% EDTA + 2% CHX resulted in significantly more dead bacteria than 3 minutes of exposure to these same disinfecting solutions (P < .05). No statistically significant difference between 3 and 10 minutes was found in other groups (P > .05); 6% NaOCl + QMiX and 6% NaOCl + 17% EDTA + 2% CHX showed the strongest antibacterial effect. In the absence of a smear layer, 2% CHX and 6% NaOCl killed significantly more bacteria than they did in the presence of a smear layer (P < .05).. The smear layer reduces the effectiveness of disinfecting agents against E. faecalis in infected dentin. Solutions containing 6% NaOCl and/or QMiX showed the highest antibacterial activity.

Topics: Bacterial Load; Bacteriological Techniques; Biguanides; Chlorhexidine; Dental Pulp Cavity; Dentin; Disinfection; Drug Combinations; Edetic Acid; Enterococcus faecalis; Humans; Materials Testing; Microbial Viability; Microscopy, Confocal; Polymers; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Time Factors

The aim of this in vitro study was to assess and compare the effect of photoactivated disinfection (PAD) on the bond strength of root canal sealers to human root canal dentin using the push-out test.. Fifteen extracted human mandibular premolar teeth with single and straight roots were used. After the clinical crowns were removed from the cementoenamel junction, root canals were prepared with the ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) rotary system to the size of the F3 file. The smear layer of the roots was removed using 17% EDTA followed by 5.25% sodium hypochlorite (NaOCl) and distillate water. The roots were then randomly divided into 3 groups (n = 5) according to the final irrigation regimen. In group 1, PAD (FotoSan; CMS Dental, Copenhagen, Denmark) was applied to the root canals and light cured for 20 seconds. Group 2 was finally irrigated with a 2% solution of chlorhexidine gluconate, and group 3 served as the control group (NaOCl + EDTA). All the canals were then obturated with the lateral condensation technique using gutta-percha and AH Plus sealer (Dentsply Maillefer) sealer. One-millimeter-thick horizontal sections from the coronal and midthirds of each root (n: 5 × 4 = 20) were sliced for the push-out bond strength measurement. The data were converted to megapascals and statistically analyzed using 1-way analysis of variance and the post hoc Tukey test.. There was no significant difference among the bond strength of PAD, chlorhexidine gluconate, and NaOCl (P > .05).. We conclude that PAD does not adversely affect the bond strength of the AH Plus sealer to root canal dentin and that it can be used for the final disinfection of root canals.

Topics: Chlorhexidine; Dental Bonding; Dental Pulp Cavity; Dentin; Disinfection; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Humidity; Materials Testing; Photochemotherapy; Photosensitizing Agents; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Temperature; Time Factors; Tolonium Chloride

The purpose of this study was to evaluate the effectiveness of different irrigating methods in removing the smear layer at 1, 3, 5, and 8 mm from the apex of endodontic canals.. Sixty-five extracted single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. Specimens were shaped to ProTaper F4 (Dentsply Maillefer, Ballaigues, Switzerland) and irrigated with 5.25% NaOCl at 37°C. Teeth were divided into 5 groups (2 control groups [n = 10] and 3 test groups [n = 15]) according to the final irrigant activation/delivering technique (ie, sonic irrigation, passive ultrasonic irrigation [PUI], or apical negative pressure). Root canals were then split longitudinally and observed by field emission scanning electron microscopy. The presence of debris and a smear layer at 1, 3, 5, and 8 mm from the apex was evaluated. Scores were analyzed by Kruskal-Wallis and Mann-Whitney U tests.. The EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK) was significantly more efficient than PUI and the control groups in removing the smear layer at 3, 5, and 8 mm from the apex. The EndoVac System (Discus Dental, Culver City, CA) removed statistically significantly more smear layer than all groups at 1, 3, 5, and 8 mm from the apex. At 5 and 8 mm from the apex, PUI and the EndoVac did not differ statistically significantly, but both performed statistically better than the control groups.. In our study, none of the activation/delivery systems completely removed the smear layer from the endodontic dentine walls; nevertheless, the EndoActivator and EndoVac showed the best results at 3, 5, and 8 mm (EndoActivator) and 1, 3, 5, and 8 mm (EndoVac) from the apex.

Topics: Adolescent; Adult; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Temperature; Therapeutic Irrigation; Tooth Apex; Ultrasonics; Vacuum; Young Adult

Near-infrared diode lasers can be used for several applications, which range from disinfection to smear layer removal in endodontics. This study evaluated the efficacy of agitation of 15% EDTA with an 808-nm diode laser on removal of the smear layer.. Sixty extracted human maxillary central incisor teeth were instrumented up to ProTaper F4 (Dentsply Maillefer, Ballagues, Switzerland) and then randomly divided into 6 groups (n = 10 for each group) according to the different final irrigating protocols as follows: 5% sodium hypochlorite for 120 seconds performed with the NaviTip (Dentsply Maillefer, Ballaigues, Switzerland) (control group); 15% EDTA for 120 seconds performed with the NaviTip; and agitation of 15% EDTA with an 808-nm diode laser for 10, 20, 30, and 40 seconds. Specimens were observed under a scanning electron microscope, and open dentinal tubules were counted using Adobe Photoshop software (Adobe Systems, San Jose, CA). The data were analyzed with 1-way analysis of variance and Tukey post hoc tests (P = .05).. The number of open dentinal tubules was higher in the middle thirds than in the apical thirds. The differences between the apical and middle thirds were statistically significant (P < .05). Statistically significant differences were also found between the control group and the other groups in both the middle and apical thirds of the root canals (P < .05).. The results indicated that agitation of 15% EDTA with an 808-nm diode laser for 20 seconds was effective in removing the smear layer in the apical thirds of root canals.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Female; Humans; Incisor; Lasers, Semiconductor; Male; Microscopy, Electron, Scanning; Middle Aged; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth Apex

The purpose of this study was to compare the bond strength of a new bioceramic sealer (EndoSequence BC Sealer) and AH Plus in the presence or absence of smear layer. Extracted single-rooted human teeth were prepared and randomly divided into four groups. In groups 1 and 3, the root canals were finally irrigated with 5.25% NaOCl and smear layer was not removed, but in groups 2 and 4, the root canals were finally irrigated with 17% EDTA followed by 5.25% NaOCl in order to remove the smear layer. In groups 1 and 2, the root canals were obturated with gutta-percha/AH Plus, but in groups 3 and 4, obturation was performed with gutta-percha/EndoSequence BC Sealer. Push-out bond strength and failure modes were evaluated. The bond strength of gutta-percha/AH Plus and gutta-percha/EndoSequence BC Sealer was not significantly different (P = 0.89). The presence or absence of smear layer did not significantly affect the bond strength of filling materials (P = 0.69). The mode of bond failure was mainly cohesive for all groups. In conclusion, the bond strength of the new bioceramic sealer was equal to that of AH Plus with or without the smear layer.

Topics: Calcium Phosphates; Dental Bonding; Dental Pulp Cavity; Dentin; Drug Combinations; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Microscopy, Electron, Scanning; Oxides; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Silicates; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Surface Properties

This in vitro study is an attempt to compare the effectiveness in cleaning oval shaped root canals using Anatomic Endodontic Technology (AET®), ProFile system® and Manual Instrumentation with K-files.. Sixty oval shaped single rooted maxillary and mandibular premolars with straight canals were divided in to three groups. The root canals were, confirmed as being oval shape by means of radiographs made in a buccolingual and mesiodistal direction. Automated canal preparation was performed using Anatomic Endodontic Technology (group 1) and the ProFile system® (group 2). Manual instrumentation (group 3) was performed with k-files. Irrigation was performed using alternatively 3% NaOCl and 17% EDTA, followed by rinsing with normal saline. The roots were split longitudinally into two halves and examined under a scanning electron microscope. The presence of debris and smear layer was recorded at distances 1, 5 and 10 mm from the working length using a three step scoring scale. Mean scores for debris and smear layer was calculated and statistically analyzed for between and within groups significance, using the Kruskal-Wallis nonparametric ANOVA test and Bonferroni's multiple comparison test.. At 1, 5 and 10 mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls as compared to canals prepared with ProFile system® or manual instrumentation. For all three groups significantly lower mean smear layer scores (p < 0.05) were recorded at 5 and 10 mm levels compared with the 1 mm level. Significantly lower mean debris scores (p < 0.05) were also recorded at 5 and 10 mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile system® and manual instrumentation groups.. Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved with any of the techniques and instruments investigated.

Topics: Bicuspid; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Technology, Dental

The aim of this study was to compare the effectiveness of the F-fle with an ultrasonically activated #15 K-fle in removing the smear layer after biomechanical instrumentation along with irrigation of Saline, NaOCl and with or without a fush of EDTA.. Sixty decoronated human premolar teeth with a single canal were instrumented with ProTaper using S1, S2 and F1 series to produce the smear layer and randomly divided into two groups. Group A used Ultrasonics and group B used F-fle for activation of irrigants respectively. Each group was further divided in to three subgroups consisting of 10 teeth in each as I, II, III consisting of saline, NaOCl, NaOCl and EDTA as irrigants respectively. SEM micrographs were taken and amount of smear layer removal was analyzed by using Chi-square statistics tests.. Most effective smear layer removal was seen only when EDTA was used. There was no statistically signifcant difference between the groups A and B in removal of smear layer.. There was no increase in smear layer between use of F-fle when compared with the Ultrasonically activated K-fle. CLINICAL SIGNIFCANCE: The F-fle although does not have a superior effcacy than the ultrasonics in removal of smear layer from root canals but when used along with EDTA, can be an effective alternative for the dentists who are unable to bear the initial setup cost of ultrasonics.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Therapeutic Irrigation; Tooth Apex; Ultrasonics; Vibration

The present study was conducted to compare the cleaning efficacy (debris and smear layer removal) of hand and two NiTi rotary instrumentation systems (K3 and ProTaper).. Sixty single rooted human maxillary anterior teeth decoronated at the cementoenamel junction were used. All the specimens were divided into four groups of 15 teeth each, group I--ProTaper rotary instrumentation done, group II--K3 rotary instrumentation done, group III--Stainless steel K-file instrumentation done, group IV--root canal irrigation without instrumentation. Root canal preparation was done in a crown down manner and 3% sodium hypochlorite was used as irrigant after each file followed by final rinse with 5 ml of 17% EDTA solution, then specimens were scanning electron microscopic (SEM) examination.. Statistical analysis was done using one-way ANOVA followed by post hoc Tukey's HSD test. Group I showed highly statistical significant difference compared to other groups. There was no statistically significant difference considering smear layer at any levels among the groups with no smear layer formation in group IV.. ProTaper rotary instrumentation showed the maximum cleaning efficacy followed by K3 rotary instrumentation in the coronal, middle and apical thirds of the root canal.. ProTaper rotary instruments are more efficient than hand and K3 rotary instruments during root canal treatment.

Topics: Dental Alloys; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Nickel; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Stainless Steel; Therapeutic Irrigation; Titanium; Tooth Apex

To evaluate clinically the antibacterial effects of root canal treatment procedures using molecular microbiology analyses.. Samples were taken from 14 necrotic root canals of teeth with apical periodontitis before (S1) and after instrumentation with NaOCl irrigation (S2), a final rinse with chlorhexidine (CHX) (S3) and then one-week interappointment medication with calcium hydroxide/CHX paste (S4). The parameters examined included the following: incidence of positive broad-range PCR results for bacterial presence; impact on bacterial community structures evaluated by PCR-Denaturing Gradient Gel Electrophoresis (DGGE); quantitative bacterial reduction determined by real-time PCR; and identification of bacterial persisters by cloning and sequencing. Data from the different tests were subjected to statistical analyses and diversity indicator calculations.. All S1 samples were positive for bacteria in all tests. Treatment procedures promoted a decrease in microbial diversity and significantly reduced the incidence of positive results and the bacterial counts (P < 0.05). In general, each subsequent treatment step improved disinfection. No specific taxon or community pattern was associated with post-treatment samples.. Supplementary steps consisting of a final rinse with CHX followed by calcium hydroxide interappointment medication promoted further decrease in the bacterial bioburden to levels significantly below those achieved by the chemomechanical procedures alone. Because the long-term outcome of root canal treatment is dependent upon maximal bacterial reduction, the present results are of clinical relevance.

Topics: Anti-Infective Agents, Local; Bacterial Load; Biodiversity; Calcium Hydroxide; Chlorhexidine; Denaturing Gradient Gel Electrophoresis; Dental Alloys; Dental Pulp; Dental Pulp Cavity; Dental Pulp Necrosis; Disinfection; Edetic Acid; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Microbial Consortia; Molecular Biology; Nickel; Periapical Periodontitis; Real-Time Polymerase Chain Reaction; RNA, Bacterial; RNA, Ribosomal, 16S; Root Canal Irrigants; Root Canal Preparation; Sequence Analysis, RNA; Smear Layer; Sodium Hypochlorite; Titanium

Complete sterilization of an infected root canal is an important challenge in endodontic treatment. Traditional methods often cannot achieve high-efficiency sterilization because of the complexity of the root canal system. The objective of the study was to investigate in vitro the feasibility of using a cold plasma treatment of a root canal infected with Enterococcus faecalis biofilms.. Seventy single-root teeth infected with E. faecalis biofilms were divided into 7 groups. Group 1 served as the negative control group (no treatment), and group 7 was the positive control group with teeth treated with calcium hydroxide intracanal medication for 7 days. Groups 2 to 6 included teeth treated by cold plasma for 2, 4, 6, 8, and 10 minutes, respectively. The disinfection of the E. faecalis biofilm was evaluated by colony-forming unit (CFU) counting. Scanning electron microscopy was used to evaluate the structural changes of the E. faecalis biofilm before and after plasma treatment. Confocal scanning laser microscopy was used to investigate the vitality of the microorganisms in the biofilm before and after plasma treatment.. A significant decrease in the number of CFUs was observed after prolonged cold plasma treatment (based on the statistical analysis of the teeth in groups 2-6). Compared with the positive control group, cold plasma treatment of 8 or 10 minutes (groups 5 and 6) had a significantly higher antimicrobial efficacy (P < .05). The scanning electron microscopic analysis showed that the bacteria membrane was ruptured, and the structure of the biofilm was fully destroyed by the plasma. Confocal scanning laser microscopic studies indicated that the plasma treatment induced E. faecalis death and destruction of the biofilm.. The cold plasma had a high efficiency in disinfecting the E. faecalis biofilms in in vitro dental root canal treatment.

Topics: Bacterial Load; Biofilms; Calcium Hydroxide; Dental Disinfectants; Dental Pulp Cavity; Disinfection; Enterococcus faecalis; Feasibility Studies; Gram-Positive Bacterial Infections; Humans; Microscopy, Confocal; Microscopy, Electron, Scanning; Plasma Gases; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Time Factors

This in vivo study used molecular microbiology methods to evaluate the effects of passive ultrasonic irrigation (PUI) as a supplementary disinfecting step after root canal preparation.. Samples were taken from 10 necrotic root canals of teeth with apical periodontitis before (S1) and after rotary nickel-titanium instrumentation using 2.5% NaOCl as the irrigant (S2) and then after PUI for NaOCl activation (S3). The parameters examined included the incidence of positive broad-range polymerase chain reaction (PCR) results for bacterial presence, the impact on bacterial diversity evaluated by PCR-denaturing gradient gel electrophoresis (DGGE), the quantitative bacterial reduction determined by real-time PCR, and the identification of persistent species by clone library analysis.. All S1 samples were positive for bacteria in all tests. Treatment procedures were significantly effective in reducing the incidence of positive results for bacteria, the number of bacterial cells (infectious bioburden), and the bacterial diversity (number of species and abundance). However, the supplementary PUI approach did not succeed in significantly enhancing disinfection beyond that achieved by chemomechanical preparation. Several bacterial species/phylotypes were identified in post-treatment samples that were positive for bacteria.. Findings from this clinical study including a small sample size suggest that PUI can be ineffective in significantly improving disinfection of the main root canal after chemomechanical procedures.

Topics: Actinobacteria; Bacteria; Bacterial Load; Campylobacter; Dental Alloys; Dental Pulp Cavity; Dental Pulp Necrosis; Electrophoresis; Fusobacterium nucleatum; Gram-Positive Bacteria; Humans; Nickel; Periapical Periodontitis; Pseudomonas aeruginosa; Real-Time Polymerase Chain Reaction; RNA, Bacterial; RNA, Ribosomal, 16S; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Therapeutic Irrigation; Titanium; Ultrasonics

The aim of the present study was to assess the bond strength of root fillings in oval-shaped canals prepared with the self-adjusting file (SAF) system.. A careful specimen selection resulted in 2 equal groups, each consisting of 12 extracted mandibular canines with oval canals that had vital pulps before extraction. One group was subjected to the SAF protocol, and the other group underwent conventional protocol, which was the ProTaper system with syringe-needle irrigation. Full-strength sodium hypochlorite was used as an irrigant for both groups. The teeth were obturated in a standardized way, filled with a lentulo spiral as the root filling, and then prepared for micropush-out assessment by using root slices of 1-mm thickness. Loading was performed on a universal testing machine at a speed of 0.5 mm/min(-1). The Student's t test for pairwise comparisons was applied to assess the effect of each preparation technique on the push-out bond strength.. All specimens showed measurable adhesive properties to root dentin. In addition, no premature failure occurred. The group-by-location interaction was significant (P = .0071); thus, the group comparisons were dependent on the canal third. Overall, the push-out bond strength was the highest in the coronal third and the lowest in the apical third. SAF-prepared specimens displayed significantly higher bond strengths (P = .0012, 0.51-5.9 MPa).. The present study showed that SAF preparation markedly influenced root-filling push-out bond strength in oval-shaped canals. Further investigations are needed to provide a better understanding of the physicochemical modifications of the root dentin prepared with the SAF cleaning-shaping-irrigation system.

Topics: Adhesiveness; Case-Control Studies; Cuspid; Dental Bonding; Dental Pulp Cavity; Dental Stress Analysis; Epoxy Resins; Equipment Design; Humans; Materials Testing; Needles; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Syringes; Therapeutic Irrigation; Tooth Apex

To compare the antibacterial efficacy of two instrumentation techniques, one using hand nickel-titanium (NiTi) instruments and the other using rotary NiTi instruments, in root canals of teeth with apical periodontitis.. Root canals from single-rooted teeth were instrumented using either hand NiTi instruments in the alternated rotation motion technique or rotary BioRaCe instruments. The irrigant used in both groups was 2.5% NaOCl. DNA extracts from samples taken before and after instrumentation were subjected to quantitative analysis by real-time polymerase chain reaction (qPCR). Qualitative analysis was also performed using presence/absence data from culture and qPCR assays.. Bacteria were detected in all S1 samples by both methods. In culture analysis, 45% and 35% of the canals were still positive for bacterial presence after hand and rotary NiTi instrumentation, respectively (P > 0.05). Rotary NiTi instrumentation resulted in significantly fewer qPCR-positive cases (60%) than hand NiTi instrumentation (95%) (P = 0.01). Intergroup comparison of quantitative data showed no significant difference between the two techniques.. There was no significant difference in bacterial reduction in infected canals after instrumentation using hand or rotary NiTi instruments. In terms of incidence of positive results for bacteria, culture also showed no significant differences between the groups, but the rotary NiTi instrumentation resulted in more negative results in the more sensitive qPCR analysis.

Topics: Bacteria; Bacterial Load; Bacteriological Techniques; Dental Alloys; Dental Pulp Cavity; Dental Pulp Necrosis; Dentin; Edetic Acid; Equipment Design; Humans; Nickel; Periapical Periodontitis; Real-Time Polymerase Chain Reaction; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Titanium

The purpose of this study was to examine, morphologically and histochemically, five types of conditioning effects on cavities prepared with an Er,Cr:YSGG laser and an air-turbine. Cavities were prepared using a Waterlase(®) MD turbo handpiece (W) and an air-turbine (AT) on human extracted molars. The cavity conditionings used were non-conditioned (G1), K-etchant Gel (G2), K-etchant Gel + AD Gel (G3), Clearfil SE Bond primer (G4) and Clearfil S(3) Bond (G5). On naked eye observations, enamel of G1, G2 and G3 in the W cavities and etched enamel of G2 and G3 in the AT cavities were observed as rough and dull in appearance. G4 and G5 in W and AT cavities were observed as shiny surfaces. On SEM observations, no smeared layer was observed in W cavities, while a smeared layer and bur-scratches were observed in AT cavities. In W cavities, rough surfaces were observed on enamel. That is, cracks and minute rough surfaces were observed. In contrast, equally etched scale-shaped enamel rods were observed in AT cavities. Widely opened dentinal tubules and protruding peritubular matrices of dentin were observed in W cavities. A few remaining smeared plugs could be observed at the AT cavities. On LM observations, 13-16 μm layers of the dentin in G1, G2, G4 and G5 of W cavities were stained red in color by the Azan staining method, while redness was not observed in G3. No groups were stained red in AT cavities. It was considered that layers stained red in color were thermal degeneration layers of dentin induced by W. Namely 30 s etching of 40% phosphoric acid gel followed by 90 s treatment of 10% NaClO gel should be recommended for use when combined with an Er,Cr:YSGG laser for cavity preparation.

Topics: Acid Etching, Dental; Coloring Agents; Dental Cavity Preparation; Dental Enamel; Dental High-Speed Equipment; Dentin; Dentin-Bonding Agents; Humans; Lasers, Solid-State; Microscopy, Electron, Scanning; Phosphoric Acids; Resin Cements; Smear Layer; Sodium Hypochlorite; Time Factors

To evaluate the effect of intracanal dentine wettability on human dental pulp cell (HDPC) attachment after application of endodontic irrigants.. Twenty extracted human premolar teeth with straight canals were sectioned at the apical and coronal thirds of each root, and the remaining mid-root portions were bisected longitudinally. After polishing, the specimens were divided into two groups for wettability and cell attachment measurements, respectively. The intracanal surface wettability was assessed by atomic force microscopy after a rinse of H(2) O (control), 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and MTAD (n = 5). Additionally, HDPCs were seeded onto the irrigated root canal dentine and the cell attachment was evaluated by calcein-CAM and propidium iodide (PI) dying under fluorescence microscope (n = 5). Data were analysed by means of one-way anova and LSD test.. Compared with the control group, 5.25% NaOCl, 17% EDTA and MTAD treatment significantly increased surface wettability (P < 0.001). The rank order of adhesion force was MTAD >17% EDTA >5.25% NaOCl > H(2) O. The highest average numbers of viable HDPCs were observed on the root canals irrigated with MTAD, followed by the 17% EDTA group (P < 0.001), and the lowest average numbers of viable cells were detected in the 5.25% NaOCl and H(2) O groups.. Surface wettability was affected by the irrigants. Increasing in wettability produced higher levels of HDPC attachment to irrigated dentine.

Topics: Adolescent; Adult; Cell Adhesion; Cell Survival; Chelating Agents; Citric Acid; Coloring Agents; Dental Pulp; Dental Pulp Cavity; Dentin; Doxycycline; Edetic Acid; Fluoresceins; Fluorescent Dyes; Humans; Microscopy, Atomic Force; Microscopy, Fluorescence; Polysorbates; Propidium; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Water; Wettability; Young Adult

The purpose of this study was to determine current trends in irrigation selection among endodontists.. An invitation to participate in a web-based survey (QuestionPro) was e-mailed to 3844 members of the American Association of Endodontists. Survey participants were asked between 10 and 14 questions based on their individual responses. Among other questions, participants were asked about their irrigant selection, irrigant concentration, smear layer removal, and use of adjuncts to irrigation.. A total of 3707 survey invitations were successfully delivered by e-mail after accounting for several undeliverable e-mail invitations. There were 1102 participants, with an overall completion rate of 28.5% (n = 1054). Our data indicate that >90% of respondents primarily use sodium hypochlorite, with 57% of them using it at a concentration >5.0%. Seventy-seven percent of respondents aim to remove the smear layer during endodontic treatment. At least 45% of respondents reported using an adjunct to irrigation.. Most of the respondents are using full-strength sodium hypochlorite and are routinely removing the smear layer during endodontic treatment. In addition, almost half of the respondents are using an adjunct, such as ultrasonic activation, to aid in their irrigation technique.

Topics: Chlorhexidine; Edetic Acid; Endodontics; Humans; Internet; Practice Patterns, Dentists'; Pressure; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics

The objectives of this study were to evaluate and compare the time-dependent chemical and ultramorphologic effects of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) in young and old dentin.. Sixty-four teeth scheduled for extraction were collected from young (<30 years) and old (>60 years) patients. In 48 teeth, the dentin was reduced to a powder state and treated with EDTA or EDTA + NaOCl for 1 and 10 minutes, respectively. X-ray diffraction analysis was used to determine the changes in the composition of dentin through dissolution of hydroxyapatite (HAp). In the remaining teeth (n = 16), the root canals were prepared, bisected, and subjected to the same time-dependent treatment regimens. The changes in the number and area of dentinal tubules were calculated by image analysis. The data were analyzed statistically by paired t test and one-way analysis of variance, followed by Tukey honestly significant difference test at P = .05.. In both young and old dentin, EDTA significantly decreased the HAp intensity at 1 and 10 minutes, whereas EDTA + NaOCl only decreased that of old dentin at 10 minutes. Pair-wise comparisons revealed that in old dentin, the reduction in HAp intensity after treatment with EDTA and EDTA + NaOCl was significantly greater at 10 minutes than at 1 minute, whereas in young dentin, a significant decrease was only observed in the EDTA/10-minute subgroup. Compared with their 1-minute counterparts, 10-minute treatment with EDTA + NaOCl significantly increased the tubular diameter and tubular area of old dentin. In young dentin, the tubular area and diameter values were not affected by treatment time (P > .05).. In young root dentin, 10-minute treatment with EDTA + NaOCl does not significantly alter the chemical and ultramorphologic structure and thus appears to be unnecessary. In old dentin, extended treatment time with EDTA + NaOCl should be avoided owing to excessive demineralization and erosion. In both types of dentin, EDTA was not effective in complete removal of the smear layer.

Topics: Adult; Age Factors; Chelating Agents; Dental Pulp Cavity; Dentin; Durapatite; Edetic Acid; Humans; Image Processing, Computer-Assisted; Microscopy, Electron, Scanning; Middle Aged; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Time Factors; X-Ray Diffraction

This article describes a case of recurrent post-treatment apical periodontitis and late failure after endodontic retreatment performed in a single visit.. The patient presented with a tooth exhibiting inadequate endodontic treatment and a large periradicular lesion that extended laterally to the root. Retreatment was performed in a single visit and involved chemomechanical preparation using 5.25% NaOCl as the irrigant and root canal obturation by Schilder's vertical compaction technique. A large lateral canal was radiographically revealed after obturation. After 2 years, the lesion was no longer radiographically discernible, a condition that was confirmed 9 years after retreatment procedures. Nonetheless, after 12 years, radiographs revealed recurrent disease. Apical surgery was performed, and the root apex, including the area of the large lateral canal, was resected with care to maintain the lesion attached to it. The biopsy specimen was subjected to histopathologic and histobacteriologic analyses.. Longitudinal sections of the apical root specimen revealed a heavy dentinal tubule infection surrounding the area of the lateral canal. Bacteria were not found in any other area of the specimen. No other possible reason for the inflammatory periradicular lesion, such as root fracture, coronal leakage, or foreign-body reaction, was evident.. A persistent intraradicular infection caused by bacteria located within dentinal tubules is the most reasonable explanation for resurgence of the apical periodontitis lesion. This case report stresses the importance of attaining proper disinfection of the root canal system for a predictable long-term outcome of the treatment.

Topics: Adult; Aluminum Compounds; Apicoectomy; Biopsy; Calcium Compounds; Dental Pulp Cavity; Dentin; Drug Combinations; Female; Follow-Up Studies; Gutta-Percha; Humans; Oxides; Periapical Periodontitis; Recurrence; Retreatment; Retrograde Obturation; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Silicates; Smear Layer; Sodium Hypochlorite; Tooth Apex; Treatment Failure

To evaluate the scrubbing effect of self-etching adhesive systems on the microtensile bond strengths to sodium hypochlorite-treated dentin.. The occlusal surfaces of 36 extracted human third molars were horizontally cut to expose sound dentin. The dentin surfaces of the teeth were treated with 6% NaOCl aqueous solution for 30 s or none. After water rinsing for 10 s and air drying, a 2-step (Clearfil Protect Bond) or 1-step (Clearfil S3 Bond or Bond Force) self-etching adhesive was applied with or without a scrubbing technique, and resin composite (Clearfil AP-X) crowns were built up. The bonded specimens were stored in water for 24 h and then subjected to the microtensile bond test at a crosshead speed of 1.0 mm/min. Data were analyzed using three-way ANOVA and Bonferroni multiple comparisons (p < 0.05).. The NaOCl-treated dentin exhibited significantly lower bond strength with the tested self-etching adhesive systems than did the normal dentin (p < 0.05). Using a scrubbing technique for the tested self-etching adhesive systems significantly improved the µTBS to NaOCl-treated dentin (p < 0.05), whereas there was no significant difference in µTBS to normal dentin between a scrubbing and nonscrubbing technique (p > 0.05).. Using a scrubbing technique for applying self-etching adhesive systems to NaOCl-treated dentin was effective in improving the compromised bonding.

Topics: Acid Etching, Dental; Analysis of Variance; Dental Bonding; Dental Stress Analysis; Dentin; Dentin Permeability; Dentin-Bonding Agents; Friction; Humans; Materials Testing; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Tensile Strength

To determine whether sodium hypochlorite (NaOCl) with 0.2% chlorhexidine gluconate (CHX) leads to colour change and precipitate formation, and to ultrastructurally analyse the dentine surface after simultaneous irrigation with 0.5% NaOCl and 0.2% CHX. Four tubes in which 5ml of different NaOCl concentrations and 5ml 0,2% CHX were placed, were observed every 15 minutes in the first two hours and after 7 days. Mixture solutions were centrifuged at 800 rpm/4 min. A precipitate is observed under light-microscopy. Thirty-five single-rooted teeth were instrumented using crown-down technique with irrigation: Positive control: distilled water, Negative control: 0,5% NaOCl+15% EDTA, Experimental group: identical to the negative control, then canals were treated with 0.5% NaOCl+0.2% CHX. The longitudinal root sections were observed under scanning-electron-microscopy. The amount of debris was assessed with 5/score-system, and the results were analysed using the Mann-Whitney U test (p < 0.001). Change in colour was noticed immediately after the merger and it did not change with time. Mixture solutions showed considerable turbidity, but precipitate was observed only after centrifugation. Statistical analysis showed a significant difference in the dentinal wall purity when comparing the cervical and middle root canal thirds between the experimental and negative control group. The difference was also observed between the cervical and middle thirds compared to the apical third of the root canal within these groups. Interaction between NaOCl and CHX, as well as the creation of precipitates, depends not only on the concentration of NaOCl, but also on the concentration of CHX.

Topics: Centrifugation; Chemical Precipitation; Chlorhexidine; Color; Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Nephelometry and Turbidimetry; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Tooth; Tooth Discoloration

Bacterial reduction in oval-shaped root canals by a single-instrument technique was compared ex vivo with a conventional nickel-titanium rotary technique. Data obtained from two quantification methods, quantitative real-time polymerase chain reaction (qPCR) and culture, were also compared.. Oval-shaped canals of extracted teeth contaminated with Enterococcus faecalis were instrumented using either a single Reciproc instrument or the BioRaCe instrument series. Bacteriological samples were taken before (S1) and after instrumentation (S2). Bacterial quantification was performed using qPCR and culture.. Intragroup analysis showed that both protocols promoted a highly significant bacterial reduction (P < 0.001). Intergroup analysis (S2 samples) showed no significant differences between the two instrumentation systems (P > 0.05). As for the quantification methods, qPCR revealed significantly higher counts of E. faecalis in S1 than culture (P < 0.05), but no significant differences occurred for S2 (P > 0.05).. The single-file technique was comparable with the conventional technique in oval-shaped canals provided the width of apical preparation, volume of irrigants and duration of irrigation are kept similar. No significant difference was observed for qPCR and culture in post-instrumentation samples, indicating that both methods can be reliably used for studies of antibacterial effectiveness.

Topics: Bacterial Load; Bacteriological Techniques; Bicuspid; Biofilms; Dental Alloys; Dental Pulp Cavity; Edetic Acid; Enterococcus faecalis; Equipment Design; Humans; Incisor; Materials Testing; Microscopy, Electron, Scanning; Nickel; Real-Time Polymerase Chain Reaction; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Titanium

To compare the smear layer and debris removal effectiveness of four root canal irrigation protocols as well as their effectiveness in removing remaining soft tissues in curved root canals.. The mesiobuccal and mesial root canals of 107 extracted human maxillary and mandibular molars were instrumented using Mtwo rotary NiTi instruments then randomly divided into four groups according to a final rinse protocol: Group 1 (n = 28) - manual agitation of 1% NaOCl and 15% EDTA; Group 2 (n = 26) - CanalBrush agitation of 1% NaOCl and 15% EDTA; Group 3 (n = 26) - 3% H(2) O(2) alternated with 1% NaOCl; Group 4 (n = 27) - passive ultrasonic agitation of 1% NaOCl and 15% EDTA. All irrigation protocols were performed in a closed system. Eleven roots per group were prepared and histologically stained (H&E) to assess percentage of remaining pulpal tissues in the apical thirds. The remaining specimens were split longitudinally and examined under scanning electron microscope at ×2000 magnification to assess smear layer and debris removal. Image Pro Plus 6.0 software was used to analyse smear layer and remaining pulp tissue. Debris presence was scored by two blinded investigators using a five-point scale. Data were analysed using Univariate analysis of variance (GenStat 13, α = 0.05).. CanalBrush and passive ultrasonic irrigation were equally effective with significantly less smear layer and debris than manual agitation and H(2) O(2) alternated with NaOCl (P < 0.05). The H(2) O(2) alternated with NaOCl protocol was significantly more effective in removing pulp tissue remnants in the apical level than manual agitation (P = 0.009) and passive ultrasonic irrigation (P = 0.01).. CanalBrush was as effective as passive ultrasonic irrigation in smear layer and debris removal. Alternating H(2) O(2) with NaOCl was effective in removing soft tissues from root canal complexities. Further studies are required to evaluate effectiveness of this regimen taking into account irrigant volume differences and effect of root canal system configuration.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Molar; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy; Vibration

To evaluate the effect of Carisolv on endodontic microleakage by establishing a fluid transport model using sodium nitrite as tracer.. Seventy extracted teeth were randomly divided into 5 groups, all the root canals were prepared with different chemical reagents, including Carisolv,3% hydrogen peroxide+ 2%tosylchloramide sodium,2.5% sodium hypochlorite,5% sodium hypochlorite(negative control)and distilled water(positive control),post spaces were prepared after cold lateral condensation, the samples were put on the model, concentration of sodium nitrite which penetrated from the coronal to the apical end was measured by diazo reaction at 1,2,4,7,10,15,20,25,30,35,40,45,50,55 and 60 day. The data were analyzed by ANOVA using SPSS 11.5 software package.. Sodium nitrite was not detected in negative control group from 1 day to 60 days. High concentration of sodium nitrite was detected in positive control group at first day, concentration of sodium nitrite was higher than that of other four groups from 1day to 60 days(P<0.01). Concentration of sodium nitrite in Carisolv group was significantly lower than that of 3%hydrogen peroxide+ 2% tosylchloramide sodium group(P<0.01), also lower than that of 2.5% sodium hypochlorite group(P<0.05),except at 25,30,35 and 40 days.. Carisolv can remove the smear layer, decrease the endodontic microleakage, seal the root canal better. The fluid transport model using sodium nitrite as tracer can be used to evaluate the endodontic microleakage objectively,sensitively and exactly.

Topics: Dental Pulp Cavity; Glutamic Acid; Humans; Leucine; Lysine; Random Allocation; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite

The ability of 2 different approaches to supplement the antimicrobial effects of chemomechanical debridement in infected root canals was compared in vivo.. Samples from necrotic root canals of teeth with apical periodontitis were taken at the baseline (S1), after preparation with rotary nickel-titanium BioRaCe instruments and 2.5% NaOCl irrigation (S2), and then after either passive ultrasonic irrigation (PUI) for activation of NaOCl (n = 13) or a final rinse with 2% chlorhexidine (CHX) (n = 14) (S3). The incidence of positive culture for bacteria and fungi as well as positive broad-range polymerase chain reaction (PCR) results for bacteria, fungi, and archaea was determined.. All S1 samples were positive for bacteria in all methods. Fungi were not detected, and archaea occurred in only one S1 sample. Treatment procedures were significantly effective in reducing the incidence of positive culture and PCR results. Although both supplementary approaches reduced the incidence of positive bacteriologic results when compared with postinstrumentation samples, reduction was not statistically significant (P > .05). There was no significant difference for intergroup comparisons either (P > .05).. Although supplementary disinfection with either PUI or a final rinse with CHX can reduce the number of cases with positive culture and PCR results for bacteria, many cases still remain with detectable bacteria in the main root canal. Research on alternative or supplementary antimicrobial methods or substances should be encouraged.

Topics: Anti-Infective Agents, Local; Archaea; Bacteria; Chlorhexidine; Dental Alloys; Dental Pulp Cavity; Dental Pulp Necrosis; Equipment Design; Fungi; Humans; Iodine; Microbiological Techniques; Nickel; Periapical Periodontitis; Polymerase Chain Reaction; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Titanium; Ultrasonics

MicroCT allows the complex canal network of teeth to be mapped but does not readily distinguish between structural tissue (dentine) and the debris generated during cleaning. The aim was to introduce a validated approach for identifying debris following routine instrumentation and disinfection.. The mesial canals of 12 mandibular molars were instrumented, and irrigated with EDTA and NaOCl. MicroCT images before and after instrumentation and images were assessed qualitatively and quantitatively.. Debris in the canal space was identified through morphological image analysis and superimposition of the images before and after instrumentation. This revealed that the removal of debris is prohibited by protrusions and micro-canals within the tooth creating areas which are inaccessible to the irrigant. Although the results arising from the analytical methodology did provide measurements of debris produced, biological differences in the canals resulted in variances. Both irrigants reduced debris compared to the control which decreased with EDTA and further with NaOCl. However, anatomical variation did not allow definitive conclusions on which irrigant was best to use although both reduced debris build up.. This work presents a new approach for distinguishing between debris and structural inorganic tissue in root canals of teeth. The application may prove useful in other calcified tissue shape determination.. Remaining debris may contain bacteria and obstruct the flow of irrigating solutions into lateral canal anatomy. This new approach for detecting the amount of remaining debris in canal systems following instrumentation provides a clearer methodology of the identification of such debris.

Topics: Algorithms; Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Molar; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; X-Ray Microtomography

Enterococcus faecalis is a species commonly isolated from persistent root canal infections. The purpose of this study was to compare the antibacterial effects of different disinfecting solutions on young and old E. faecalis biofilms in dentin canals using a novel dentin infection model and confocal laser scanning microscopy (CLSM).. The bacteria were introduced into the dentinal tubules by centrifugation. After 1 day and 3 weeks of incubation, 40 infected dentin specimens were subjected to 1 and 3 minutes of exposure to disinfecting solutions, which included 2% sodium hypochlorite (NaOCl) (EMD Chemicals Inc, Darmstadt, Germany), 6% NaOCl, 2% chlorhexidine (CHX) (Sigma Chemical Co, St Louis, MO), and QMiX (Dentsply Tulsa Dental, Tulsa, OK). The proportions of dead and live bacteria inside the dentinal tubules after exposure to these disinfectants were assessed by CLSM using a LIVE/DEAD bacterial viability stain.. Significantly fewer bacteria were killed in the 3-week-old dentin biofilm than in the 1-day-old biofilm. Three minutes of exposure resulted in more dead bacteria than 1 minute of exposure for both biofilms in all experimental groups (P < .05). Six percent NaOCl and QMiX were the most effective disinfecting solutions against the young biofilm, whereas against the 3-week-old biofilm, 6% NaOCl was the most effective followed by QMiX. Two percent NaOCl was equally effective as 2% CHX. All the disinfecting agents killed significantly more bacteria than the sterile water used as a negative control (P < .05).. Within dentin canals, bacteria in established biofilms are less easily killed by endodontic medicaments than bacteria in young biofilms.

Topics: Anti-Infective Agents, Local; Biguanides; Biofilms; Chlorhexidine; Dentin; Dentinal Fluid; Enterococcus faecalis; Humans; Microbial Viability; Microscopy, Confocal; Polymers; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Time Factors

The aim of this study was to evaluate the effect of MTAD as final rinse on removal of the smear layer subsequent to primary irrigation with 1.3% sodium hypochlorite (NaOCl) during 10-minute instrumentation periods.. Forty teeth were divided into 2 experimental groups, each containing 15 teeth, and 1 positive control group of 10 teeth. The canals were prepared with hand and rotary instruments. In the MTAD group, the root canals were flushed with 1.3% NaOCl solution during 10-minute instrumentation, and MTAD was used as the final rinse. In other experimental group, 5.25% NaOCl was used during instrumentation, and 17% ethylenediaminetetraacetic acid (EDTA) was used as the final rinse. In the positive control group, sterile distilled water was used for irrigation. The overall instrumentation period for each canal was 10 minutes. The amount of the smear layer and degree of erosion qualified according to the study by Torabinejad et al by using a scanning electron microscope. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests. All statistical analyses were set with a significance level of α = 0.05.. In the positive control group, debris and heavy smear layer covered the root canal surface and the tubules. In MTAD group, moderate smear layer covered the root canal surface and the tubules. In EDTA group, there was no smear layer on surface of canals. There were significant differences between groups (α < 0.0001). Mann-Whitney test showed significant difference between experimental groups (α = 0.01).. In 10-minute instrumentation period, the use of 5.25% NaOCl during instrumentation and 17% EDTA as the final rinse is more effective than using 1.3% NaOCl as primary irrigation and MTAD as final rinse on removal of the smear layer.

Topics: Citric Acid; Doxycycline; Edetic Acid; Humans; Molar; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Time Factors

To assess in a laboratory experimental model the efficacy of a novel root canal irrigant, QMiX, against Enterococcus faecalis and mixed plaque bacteria in planktonic phase and biofilms. In addition, its ability to remove smear layer was examined.. Enterococcus faecalis and mixed plaque bacteria were exposed to QMiX, 2% chlorhexidine (CHX), MTAD and 1% sodium hypochlorite (NaOCl) for 5 s, 30 s and 3 min. Following exposure, samples were taken, serially diluted and grown aerobically and anaerobically on tryptic soy agar (TSA) plates or on blood agar plates for 24 and 72 h, respectively, to measure killing of bacteria. E. faecalis and plaque biofilms were grown for 3 weeks on collagen-coated hydroxyapatite or dentine discs and exposed for 1 and 3 min to QMiX, 2% CHX, MTAD, 1% and 2% NaOCl. The amount of killed bacteria in biofilms was analysed by confocal laser scanning microscopy using viability staining. Dentine blocks were exposed to QMiX and 17% EDTA for 5 min. The effectiveness of smear layer removal by the solution was evaluated using scanning electron microscopy. For statistical analysis, one-way analysis of variance and comparison of two proportions were used.. QMiX and 1% NaOCl killed all planktonic E. faecalis and plaque bacteria in 5 s, while 2% CHX and MTAD were unable to kill all plaque bacteria in 30 s, and some E. faecalis cells survived even 3 min of exposure. QMiX and 2% NaOCl killed up to 12 times more biofilm bacteria than 1% NaOCl (P < 0.01), 2% CHX (P < 0.05; P < 0.001) and MTAD (P < 0.05; P < 0.001). QMiX removed smear layer equally well as EDTA (P = 0.18 × 10(-5)).. QMiX and NaOCl were superior to CHX and MTAD under laboratory conditions in killing E. faecalis and plaque bacteria in planktonic and biofilm culture. Ability to remove smear layer by QMiX was comparable to EDTA.

Topics: Anti-Infective Agents, Local; Biguanides; Biofilms; Chlorhexidine; Citric Acid; Dental Plaque; Dentin; Doxycycline; Drug Combinations; Microscopy, Confocal; Plankton; Polymers; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

This study compared canal and isthmus debridement efficacies between side-vented needle irrigation (SNI) and the VPro EndoSafe (VPro) negative-pressure device (Vista Dental, Racine, WI) in mesial roots of mandibular first molars with narrow isthmuses in a closed-canal design.. Twenty teeth with narrow isthmuses were selected using micro-computed tomography scanning. Collagen solution was reconstituted with 1% NH(4)OH to simulate debris and injected into canals via vacuum. Canals were instrumented to size 40/.04. Final irrigation was performed with 17% EDTA and 6% NaOCl using SNI with a 30-G needle or the VPro system. Roots were demineralized, and Masson trichrome-stained sections were prepared at 1.2 to 3.2 mm from the anatomic apex for a total of 6 canal levels. Debris-filled areas within the canals and isthmuses were measured using ImageJ software (National Institutes of Health, Bethesda, MD) and statistically analyzed using repeated-measures analysis.. There was no significant difference between techniques and debridement efficacy among the 6 levels within the canal (P = .108). The debridement efficacy at 1.6 mm differed significantly from that at 3.2 mm. VPro had significantly more debris at isthmus levels 2.0 and 2.4 mm than SNI (P = .009). A significant difference was observed between the canal and the isthmus (P < .001). Neither VPro nor SNI removed debris completely from the apical third or isthmus.. VPro EndoSafe did not differ significantly from SNI in the overall debridement efficacy in the apical third of mesial roots of mandibular first molars.

Topics: Azo Compounds; Collagen; Coloring Agents; Debridement; Dental Pulp Cavity; Edetic Acid; Eosine Yellowish-(YS); Equipment Design; Humans; Materials Testing; Methyl Green; Molar; Needles; Pressure; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Tooth Apex; Tooth Root; X-Ray Microtomography

To compare the effect of three techniques in root canal preparation on coronal microleakage of endodontically treated teeth.. Forty-eight human single-rooted teeth were divided into 4 groups randomly and subjected to different techniques on removal of smear layer. Group A, the control group, irrigation with hydrogen peroxide (H2O2) and normal saline (NS); group B, smear cleared with 5.25% sodium hypochlorite (NaClO) and ethylenediamine tetraacetis (EDTA) gel; group C, irrigation with Odontoson-M ultrasonics; group D, smear layer removed with Nd: YAG laser irradiation. Two specimens of every group were split longitudinally into equal segments and canal walls at coronal portion were examined under scanning electron microscope (SEM). Then ten teeth of every group were filled with warm vertical condensation by Obtura II thermoplasticized gutta-perch injection technique and sealed with zinc oxide eugenol (ZOE). The teeth were immersed in 20 g x L(-1) methylene blue for 7 days, then were demineralized, dehydrated and cleared. Linear dye penetration was determined under a steremicroscope. The data were statistically analyzed.. In group A, there were smear layer and debris remained and dentinal tubules were covered. In group B and group C, the smear layer of root canals were removed and dentinal tubules were open. In group D, the root canal dentinal tubules were sealed or semi-sealed and the smear layer were melted and ablated. The mean length of coronal microleakage for group A, B, C, D were (2.15 +/- 0.38), (1.75 +/- 0.28), (2.04 +/- 0.40), (1.73 +/- 0.36) mm. The analysis showed that the linear in group A was longer than that in group B and group D clearly (P < 0.05).. The coronal microleakage following root canal treatment could be reduced by removing smear layer with different techniques in root canal preparation.

Topics: Dental Pulp Cavity; Dentin; Humans; Hydrogen Peroxide; Lasers, Solid-State; Root Canal Filling Materials; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Tooth; Tooth Root; Tooth, Nonvital

The purpose of this study was to compare the dentin bond strength of three self-adhesive cements with smear layer pretreatments using a calcium-chelating agent (EDTA) and deproteinizing solution (NaOCl) and to evaluate their interfacial characteristics. Smear layer-covered dentin surfaces were pretreated with EDTA for 60 s, NaOCl for 5 and 15 s, or none. Three self-adhesive cements; Clearfil SA luting (Kuraray Medical), Rely X Unicem clicker (3M ESPE) and Breeze (Pentron) were applied to the dentin surfaces. After 24-h water storage, shear bond strengths to dentin were determined. In addition, nanoleakage evaluation at the interface was performed using FE-SEM and EDS. EDTA-pretreatment significantly improved the bond strength of BR (p<0.05) and NaOCl-pretreatment for 15 s significantly improved the bond strength of RX (p<0.05). On the other hand, for SA, both pretreatments significantly decreased bond strength to dentin (p<0.05). Nanoleakage formation was observed in various amounts at the cement-dentin interfaces.

Topics: Dental Bonding; Dental Cavity Preparation; Dental Leakage; Dental Stress Analysis; Dentin-Bonding Agents; Edetic Acid; Humans; Resin Cements; Shear Strength; Smear Layer; Sodium Hypochlorite

Complete debridement with smear layer removal are essential measures for achieving a successful outcome of root canal treatment. The aim of this study was to evaluate the effects of chitosan at different concentrations on the removal of the smear layer and on dentin structure after 3 and 5 min of application. Twelve recently extracted maxillary canine teeth were instrumented using the crown-down technique and irrigated with 1% sodium hypochlorite. The specimens were distributed according to the time and concentration of the final irrigating solution: G1: 0.1% chitosan for 3 min; G2: 0.2% chitosan for 3 min; G3: 0.37% chitosan for 3 min; G4: 0.1% chitosan for 5 min; G5: 0.2% chitosan for 5 min; G6: 0.37% chitosan for 5 min. All samples were prepared for SEM analysis. G1 exhibited removal of the smear layer, but not the smear plugs. G2 showed visible and open tubules with slight erosion of the peritubular dentin. Cleaning in G3 was similar to that in G2, however, the erosive effect was greater. There was expansion of the diameter of the tubules in G4; and in G5 and G6, there was severe erosion with deterioration of dentin surface. In conclusion, 0.2% chitosan for 3 min appeared to be efficient for removing the smear layer, causing little erosion of dentin.

Topics: Chelating Agents; Chitosan; Cuspid; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Time Factors

Various methods are used to evaluate irrigants. The primary aim was to develop a model for preliminary testing of potential irrigants. The second aim was to investigate the effect of bicarbonate soda on smear layer by comparing it with ethylenediamine tetraacetic acid with cetrimide (EDTAC) and sodium hypochlorite (NaOCl). Extracted human single-canal teeth were halved, and a uniform filing method was used to create smear layer. The following solutions were then applied - distilled water (control), 1% NaOCl, 17% EDTAC and bicarbonate soda at concentrations of 1%, 5%, 10% and 15%. Some samples had multiple solutions in different sequences. Samples were examined by scanning electron microscopy. Representative images were scored based on the degree of smear layer remaining. Results were analysed with the SAS system, using the GENMOD procedure. Complete smear layer was found in samples treated with all solutions except EDTAC used alone. There were no significant differences between the sequences, EDTAC/NaOCl/EDTAC and NaOCl/EDTAC/NaOCl. There were no significant differences between groups with and without bicarbonate soda. In conclusion, the model was effective for testing chemical effects on solutions on smear layer. Bicarbonate soda did not remove smear layer and provided no additional cleaning effects after EDTAC and NaOCl.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Bicarbonate; Sodium Hypochlorite

This study examined the ability of two versions of QMix, an experimental antimicrobial irrigant, on removal of canal wall smear layers and debris using an open canal design.. Cleaned and shaped single-rooted human root canals were irrigated with NaOCl as the initial irrigant and one of the following as the final irrigant: (1) QMix I (pH = 8), (2) QMix II (pH = 7.5), (3) distilled water, (4) 17% EDTA, and (5) BioPure MTAD (Dentsply Tulsa Dental Specialties, Tulsa, OK). Smear and debris scores were evaluated in the coronal, middle, and apical thirds of longitudinally fractured canal spaces using scanning electron microscopy and analyzed using Cochran-Mantel-Haenszel statistic.. Smear scores, when the overall canal was considered, differences were observed among groups except groups 1 versus 4 and groups 2 versus 4. After adjusting for canal levels, all groups differed significantly from each other (p < 0.005) with the exception of groups 2 versus 5. For the debris scores, no significant difference was observed among the treatment groups when the overall canal was considered and after adjusting for the effect of canal level.. Within the limitations of an open-canal design, the two experimental QMix versions are as effective as 17% EDTA in removing canal wall smear layers after the use of 5.25% NaOCl as the initial rinse.

Topics: Biguanides; Citric Acid; Dental Pulp Cavity; Doxycycline; Drug Therapy, Combination; Edetic Acid; Humans; Hydrogen-Ion Concentration; Polymers; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

Caries-affected dentin is covered with a thicker and organically enriched smear layer than normal dentin. This may affect the demineralization ability and the infiltration of self-etch adhesives, thus reducing the efficacy of bonding to caries-affected dentin. This study evaluated the adhesion of a two-step self-etching adhesive to normal and caries-affected dentin after pretreatment with mildly acidic hypochlorous acid (HOCl) solutions. We used a microtensile bond strength (μTBS) test to compare the μTBS of Clearfil SE Bond to either caries-affected dentin or to normal dentin, after pretreatment for 5 s with one of three solutions (806 mM NaOCl, or 0.95 or 1.91 mM HOCl). The μTBS of the self-etch adhesive was significantly lower to caries-affected dentin than to normal dentin. Pretreatment with 0.95 mM HOCl improved the μTBS of the self-etch adhesive to caries-affected dentin, but there was no significant difference compared with normal dentin. On the other hand, pretreatment with 806 mM NaOCl or 1.91 mM HOCl did not demonstrate a significant improvement in the μTBS to caries-affected dentin. None of the pretreatments demonstrated a negative effect on adhesion to normal dentin.

Topics: Acid Etching, Dental; Analysis of Variance; Dental Bonding; Dental Caries; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Humans; Hypochlorous Acid; Materials Testing; Molar; Resin Cements; Smear Layer; Sodium Hypochlorite; Tensile Strength

This ex vivo study evaluated the cleanliness of curved root canal walls after chemomechanical instrumentation using two automated systems versus manual instrumentation while using a standardized irrigation protocol.. Thirty mesial root canals of extracted human first and second mandibular molars were prepared with the TiLOS hybrid engine-driven instrumentation system (Ultradent Products Inc, South Jordan, UT) (n = 10), ProTaper engine-driven file series (n = 10), and manual instrumentation (n = 10). Irrigation was performed using alternately 5.25% sodium hypochlorite and 17% EDTA followed by rinsing with distilled water. After the roots were split longitudinally, the presence of debris and/or smear layer was visualized using serial scanning electron microscopic digital photomicrographs taken at 1, 5, and 10 mm from the working length. Mean scores for debris and the smear layer were calculated and statistically analyzed for significance (P < .05) between groups using the Kruskal-Wallis nonparametric analysis of variance and Dunn tests. The data obtained at each evaluation level for each group were analyzed using the Friedman and Tukey multiple comparison tests.. No significant differences (P > .05) were found between TiLOS and ProTaper (Dentsply/Tulsa Dental, Tulsa, OK) groups, whereas both performed significantly better than the manual instrumentation group.. Engine-driven TiLOS and ProTaper instrumentation systems combined with a standardized irrigation protocol produced cleaner root canal walls than the manual instrumentation technique although complete cleanliness was not achieved.

Topics: Dental Alloys; Dental Equipment; Dental Instruments; Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; Microscopy, Electron, Scanning; Molar; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stainless Steel; Statistics, Nonparametric; Therapeutic Irrigation; Titanium

The purpose of this study was to compare 2 irrigation techniques by evaluating canal cleanliness and obturation of lateral/accessory canals.. Seventy-five extracted canines were instrumented to a size #40/0.06 taper. The EndoActivator (EA) was compared with an ultrasonic unit for final irrigation. Each unit was used for 1 minute each with 6.15% NaOCl and 17% EDTA. A control group received syringe irrigation. Thirty teeth were sectioned and evaluated for debris removal and open dentinal tubules at 3/5 mm from the apical foramen with a scanning electron microscope. Forty-five teeth were examined for obturation of lateral canals.. The EA was significantly better in removing debris at all levels when compared with other treatment groups (P < .05) and resulted in obturation of significantly more numbers of lateral canals (P < .01.). The EA provided better obturation of lateral and accessory canals and resulted in less remaining debris.

Topics: Cuspid; Dental Pulp Cavity; Dentin; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Syringes; Therapeutic Irrigation; Tooth Apex; Ultrasonic Surgical Procedures

The purpose of the study was to examine the level of erosion on root canal wall dentin caused by immersion in different irrigant solutions in alternative sequences.. Dentin specimens from teeth with one root canal were instrumented and randomly divided into five groups. Each group was subjected to 17% EDTA, 17% ethyleneglycoltetraacetic acid (EGTA), or 10% citric acid (CA) and 5.25% sodium hypochlorite (NaOCl) varying the time of irrigant exposure and the order of the irrigants. The specimens were examined by scanning electron microscopy (SEM), and randomized digital images of the dentin surface were taken. The area of tubule openings was measured by a semiautomatic method.. No erosion was detected when demineralizing agents were used as a final rinse after NaOCl. However, the erosion of peritubular and intertubular dentin was detected when EDTA, EGTA, or CA were used first followed by 5.25% NaOCl (P < .05), and an increase over 100% in the area of dentin tubule openings was measured (P < .01).. NaOCl used as a final irrigant solution after demineralization agents causes marked erosion of root canal dentin.

Topics: Analysis of Variance; Citric Acid; Dentin; Edetic Acid; Egtazic Acid; Humans; Image Processing, Computer-Assisted; Immersion; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

Dentin surface treatment with different substances might cause alterations in chemical and structural compositions of the human dentin. The aim of this study was to investigate the wettability of endodontic sealers in contact with dentin treated with 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) in the presence or absence of smear layer.. Thirty-six dentin slices were used. They were irrigated with NaOCl and washed with distilled water (DW) to simulate irrigation during chemomechanical preparation. After this procedure, the samples were divided into 6 groups: group 1, DW (control); group 2, NaOCl + DW; group 3, CHX + DW; group 4, ethylenediaminetetraacetic acid (EDTA) + DW; group 5, EDTA + DW + NaOCl + DW; group 6, EDTA + DW + CHX + DW. The Ramé-Hart goniometer was used to measure the contact angle between the dentin surfaces and the AH Plus and Real Seal SE sealers. Data were statistically analyzed.. With regard to the contact angle between AH Plus and treated surfaces, the values of contact angle were lower when CHX was used, regardless of the presence or absence of smear layer. When Real Seal SE was evaluated, in the absence of smear layer, CHX presented lower values of contact angle. In the presence of smear layer, the use of NaOCl and CHX did not favor the spread of the sealer.. The present study has revealed that smear layer removal and final flush with CHX favor the wettability of AH Plus and Real Seal SE sealers.

Topics: Chlorhexidine; Composite Resins; Dental Pulp Cavity; Dentin; Dentin Permeability; Dentin Solubility; Drug Interactions; Edetic Acid; Epoxy Resins; Humans; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Water; Wettability

This study tested the hypothesis that the use of ethylenediamine tetraacetic acid (EDTA) as a final irrigant causes canal wall erosion only after prolonged use of 5.25% sodium hypochlorite (NaOCl) as the initial irrigant.. Two irrigation protocols were employed: (1) 5.25% NaOCl as the initial irrigant for 10 min and 17% EDTA as the final irrigant for 2 min; and (2) 5.25% NaOCl for 60 min and 17% EDTA for 2 min. Flexural strengths of dentine beams prepared from human mid-coronal dentine were evaluated using a miniature three-point bending device after they were irrigated with either protocol. Transmission electron microscopy was used to examine the conditions of instrumented canal walls irrigated with either protocol after they were bonded with methacrylate resin-based sealers.. Immersion of dentine beams in NaOCl for 60 min instead of 10 min prior to the use of EDTA resulted in a significant (p<0.001) decline in flexural strength. For both NaOCl initial rinsing times, a 2-min final irrigation with EDTA created similar 0.5 microm thick demineralisation fronts. However, extensive surface and subsurface erosion of radicular dentine was seen only when the dentine was immersed in NaOCl for 60 min.. The apparent aggressiveness of EDTA in causing canal wall erosion is attributed to the prolonged use of NaOCl. The associated decline in dentine flexural strength has potential clinical relevance when thin pulp chamber dentine is immersed in NaOCl for lengthy periods during canal instrumentation. This may render root-treated teeth more prone to vertical fracture.

Topics: Analysis of Variance; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Drug Synergism; Edetic Acid; Humans; Microscopy, Electron, Transmission; Pliability; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Tooth Demineralization; Tooth Erosion

To evaluate the pretreatment effect of mild acidic HOCl solution on the microtensile bond strength (muTBS) of a two-step self-etch adhesive to dentin and the alteration of dentin surface pH.. Thirty-nine flat ground coronal dentin specimens were divided into one control group and 12 experimental groups, which were treated with 6% NaOCl or 50, 100 and 200ppm HOCl (Comfosy) solutions for 5, 15 and 30s. After rinsing with running water for 30s, all the dentin surfaces were bonded with Clearfil SE Bond according to the manufacturer's instructions. After 24h water storage, the bonded specimens were sectioned and trimmed to an hourglass shape with a cross-sectional area of approximately 1.0mm(2) and then subjected to the muTBS test. Thirty-six mid-coronal dentin discs were used for surface pH measurement. Dentin surface pH with or without pretreatment was examined using a pH-imaging microscope (SCHEM-100). The muTBS data were analyzed by one-way ANOVA (Dunnett's T3) and the surface pH data were analyzed by non-parametric statistics (Mann-Whitney U-test).. Pretreatment with Comfosy at concentrations of 50, 100 and 200 ppm did not significantly affect muTBS regardless of the application time compared with the control group, however the 100 and 200ppm Comfosy groups showed significantly lower surface pH values. For the NaOCl pretreatment groups, a longer application time significantly decreased the muTBS and increased the surface pH values compared to the control group.. The 50ppm Comfosy pretreatments for 5, 15 and 30s did not affect the muTBS of the two-step self-etch adhesive to dentin and dentin surface pH.

Topics: Analysis of Variance; Composite Resins; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Humans; Hydrogen-Ion Concentration; Hypochlorous Acid; Light-Curing of Dental Adhesives; Methacrylates; Resin Cements; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties; Tensile Strength

The organic tissue dissolution properties of irrigating solutions are important for the success of endodontic treatment. Chlorine dioxide (ClO2) has been recently proposed as an irrigation solution in endodontics. The organic tissue dissolution property of sodium hypochlorite (NaOCl) is well-known and extensively investigated, but apparently no data have been published on tissue-dissolving properties of ClO2. The aim of this in vitro study was to compare organic tissue dissolution capacity of NaOCl and ClO2. In this study, 5.25% NaOCl, 13.8% ClO2, and, as a control, isotonic saline solutions (0.9% NaCl) were used. Thirty bovine pulp specimens were previously weighed and immersed for 20 minutes in each test solution (changing the solution every 2 minutes). The pulp specimens were then blotted dry and weighed again. The percentage of weight loss was calculated and statistically analyzed by using one-way analysis of variance and post hoc Tukey honestly significant difference tests. Saline solution did not dissolve the organic tissue. Both 5.25% NaOCl and 13.8% ClO2 dissolved the tissue pieces more effectively than saline control (P < .05). No statistically significant difference was found between the tissue-dissolving properties of 5.25% NaOCl and those of 13.8% ClO2 (P > .05). Within the limitations of this in vitro study, it was concluded that ClO2 and NaOCl are equally efficient for dissolving organic tissue.

Topics: Animals; Cattle; Chlorine Compounds; Debridement; Dental Disinfectants; Dental Pulp; Oxides; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Solubility

To introduce a new concept, the self-adjusting file (SAF), and discuss its unique features compared with current rotary nickel-titanium file systems.. The SAF file is hollow and designed as a thin cylindrical nickel-titanium lattice that adapts to the cross-section of the root canal. A single file is used throughout the procedure. It is inserted into a path initially prepared by a # 20 K-file and operated with a transline- (in-and-out) vibration. The resulting circumferential pressure allows the file's abrasive surface to gradually remove a thin uniform hard-tissue layer from the entire root canal surface, resulting in a canal with a similar cross-section but of larger dimensions. This holds also for canals with an oval or flat cross-section, which will be enlarged to a flat or oval cross-section of larger dimensions. The straightening of curved canals is also reduced because of the high pliability of the file and the absence of a rigid metal core. Thus, the original shape of the root canal is respected both longitudinally and in cross-section. The hollow SAF file is operated with a constant flow of irrigant that enters the full length of the canal and that is activated by the vibration and is replaced continuously throughout the procedure. This results in effective cleaning even at the cul de sac apical part of the canal. The SAF has high mechanical endurance; file separation does not occur; and mechanical failure, if it occurs, is limited to small tears in the latticework.. The SAF represents a new step forward in endodontic file development that may overcome many of the shortcomings of current rotary nickel-titanium file systems.

Topics: Dental Instruments; Dental Pulp Cavity; Dentin; Equipment Design; Humans; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; X-Ray Microtomography

The aim of this study was to evaluate the cleaning ability of the Self-Adjusting File (SAF) system in terms of removal of debris and smear layer.. Root canal preparations were performed in 20 root canals using an SAF operated with a continuous irrigation device. The glide path was initially established using a size 20 K-file followed by the SAF file that was operated in the root canal via a vibrating motion for a total of 4 minutes. Sodium hypochlorite (3%) and EDTA (17%) were used as continuous irrigants and were alternated every minute during this initial 4-minute period. This was followed by a 30-second rinse using EDTA applied through a nonactivated SAF and a final flush with sodium hypochlorite. The roots were split longitudinally and subjected to scanning electron microscopy (SEM). The presence of debris and a smear layer in the coronal, middle, and apical thirds of the canal were evaluated through the analysis of the SEM images using five-score evaluation systems based on reference photographs.. The SAF operation with continuous irrigation, using alternating irrigants, resulted in root canal walls that were free of debris in all thirds of the canal in all (100%) of the samples. In addition, smear layer-free surfaces were observed in 100% and 80% of the coronal and middle thirds of the canal, respectively. In the apical third of the canal, smear layer-free surfaces were found in 65% of the root canals.. The operation of the SAF system with continuous irrigation coupled with alternating sodium hypochlorite and EDTA treatment resulted in a clean and mostly smear layer-free dentinal surface in all parts of the root canal.

Topics: Dental Instruments; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Microscopy, Electron, Scanning; Observer Variation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Vibration

The aims of this study were to evaluate dentin debris removal from the root canal during ultrasonic activation of sodium hypochlorite (2% and 10%), carbonated water, and distilled water and to determine the influence of 3 ultrasonic refreshment/activation cycles of the irrigant by using the intermittent flush technique.. Root canals with a standardized groove in 1 canal wall, which was filled with dentin debris, were irrigated ultrasonically. The irrigant was refreshed and ultrasonically activated 3 times for 20 seconds. The quantity of dentin debris after irrigation was determined after each refreshment/activation cycle.. Ultrasonic activation of the irrigant combined with the intermittent flush method produces a cumulative effect over 3 refreshment/activation cycles. Sodium hypochlorite as an irrigant is significantly more effective than carbonated water, which is significantly more effective than distilled water, in removing dentin debris from the root canal during ultrasonic activation.

Topics: Dentin; Humans; Mineral Waters; Oscillometry; Rheology; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonics; Viscosity; Water

This study compared the combined use of sodium hypochlorite (NaOCl) and chlorhexidine (CXH) with citric acid and CXH on dentinal permeability and precipitate formation.. Thirty-four upper anterior teeth were prepared by rotary instrumentation and NaOCl. The root canal surfaces were conditioned for smear layer removal using 15% citric acid solution under ultrasonic activation and a final wash with distilled water. All teeth were dried, and 30 specimens were randomly divided into three equal groups as follows: positive control group (PC), no irrigation; 15% citric acid + 2% CHX group (CA + CHX); and 1% NaOCl + 2% CHX group (NaOCl + CHX). All roots were immersed in a 0.2% Rhodamine B solution for 24 hours. One-millimeter-thick slices from the cementum-enamel junction were scanned at 400 dpi and analyzed using the software ImageLab (LIDO-USP, Sao Paulo, Brazil) for the assessment of leakage in percentage. For scanning electron microscopy analysis, four teeth, irrigated for NaOCl + CHX samples, were split in half, and each third was evaluated at 1,000x and 5,000x (at the precipitate).. Using the analysis of variance test followed by the Bonferroni comparison method, no statistical differences between groups were found when analyzed at the cervical and medium thirds. At the apical third, differences between the PC and NaOCl + CHX (p < 0.05) and CA + CHX and NaOCl + CHX could be seen (p < 0.05).. The combination of 1% NaOCl and 2% CHX solutions results in the formation of a flocculate precipitate that acts as a chemical smear layer reducing the dentinal permeability in the apical third.

Topics: Analysis of Variance; Chlorhexidine; Citric Acid; Dentin; Dentin Permeability; Drug Combinations; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric

To examine the effects of varied dilutions of lactic acid as a root canal irrigant and compare the shear bond strength of Epiphany adhesive sealer to human dentin surface with other solutions deemed to be suitable root canal irrigants.. The occlusal surfaces of 60 extracted molar teeth were ground wet and treated with one of the following irrigants: 1) no irrigant (control); 1) 5% hydrogen peroxide; 3) 5% sodium hypochlorite; 4) 15% ethylenediaminetetraacetic acid (EDTA); 5) 10% lactic acid; or 6) 20% lactic acid. An additional specimen for each group was critical-point dried and freeze-fractured to evaluate the dentin surfaces after treatment by scanning electron microscopy. Specimens were treated with Epiphany primer, hollow steel tubes were placed on the dentin surfaces, and resin sealer (Epiphany) was applied to dentin inside the tubes. Specimens were stored in 100% humidity, then loaded to failure in a universal testing machine in the shear mode with a cross speed of 0.05 mm/min.. Dentin surface treatment resulted in significant differences for surface topography and shear bond strength of Epiphany sealer (P < .001). Lactic acid and EDTA significantly improved epiphany- dentin bond strengths when compared with other irrigants (P < .001). The highest mean (SD) bond strength was 1.95 (0.47) MPa for dentin surfaces treated with 20% lactic acid. The lowest mean bond strength [0.41 (0.29) MPa] was associated with untreated dentin surfaces. Scanning electron micrographs showed that the surface of the control specimens had a smear layer that contained smear plug material. Similarly, hydrogen peroxide and sodium hypochlorite produced surfaces with a smear layer. Lactic acid solutions and EDTA, however, removed the dentinal smear layer but left remnants of smear plugs in the dentinal tubules.. Lactic acid irrigant performed similarly to 15% EDTA and demonstrated higher bond strength of Epiphany sealer to dentin surface.

Topics: Adolescent; Chelating Agents; Dental Bonding; Dental Stress Analysis; Dentin; Edetic Acid; Humans; Humidity; Hydrogen Peroxide; Lactic Acid; Materials Testing; Microscopy, Electron, Scanning; Oxidants; Root Canal Filling Materials; Root Canal Irrigants; Shear Strength; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Young Adult

This study investigated the use of 3.8% silver diamine fluoride (Ag[NH3]2F) as an antibacterial agent against Enterococcus faecalis biofilms and its ability to penetrate dentinal tubules by the formation of silver salts.. Biofilms were generated on membrane filter discs and subjected to 15-minute and 60-minute exposure times with 3.8% Ag(NH3)2F, saturated Ca(OH)2, 5.25% NaOCl (negative control), and 0.9% NaCl (positive control). Cleaned and shaped radicular dentin were applied with Ag(NH3)2F for 24, 48, and 72 hours. The presence of silver salts on the dentin surface was examined using low-pressure scanning electron microscopy.. Both NaOCl and Ag(NH3)2F were effective against E. faecalis biofilms, with no significant difference in reduction of microorganisms for both exposure times. Silver deposits were present on 66.5% of the radicular dentin surfaces after 72-hour application of Ag(NH3)2F as simulated interappointment dressings. Penetration of the silver deposits was observed at most 40 microm into dentinal tubules after smear layer removal.. Ag(NH3)2F has potential to be used as an antimicrobial root canal irrigant or interappointment dressing, especially in locations in which potential browning/blackening of dentin by metallic silver is not a major concern.

Topics: Anti-Infective Agents; Bacteriological Techniques; Biofilms; Calcium Hydroxide; Colony Count, Microbial; Dental Disinfectants; Dental Pulp Cavity; Dentin; Enterococcus faecalis; Fluorides, Topical; Humans; Materials Testing; Microscopy, Electron, Scanning; Quaternary Ammonium Compounds; Root Canal Preparation; Silver Compounds; Smear Layer; Sodium Hypochlorite; Time Factors

To compare the efficacy of different solutions (1% sodium hypochlorite, 10% citric acid and 20% EDTA) in the removal of calcium hydroxide from root canals.. One hundred single-rooted maxillary incisors were prepared to size 50 and split longitudinally. Two standardized grooves were cut into the apical and coronal part of the root canal dentine and filled with calcium hydroxide. The reassembled teeth were irrigated with a syringe and a size 30 needle using the following irrigants: (i) 20% EDTA, (ii) 10% citric acid, (iii) 1% NaOCl, (iv) 10% citric acid + 1% NaOCl, (v) 20% EDTA + 1% NaOCl and (vi) water (control). Volume of irrigant was 20 mL in each group, and irrigation time was 5 min. Evaluation of cleanliness of the blinded specimens was performed by two calibrated observers under a microscope with 30x magnification using a four-grade scoring system as described by van der Sluis et al. (2007). Statistical evaluation was performed using a SAS-macro for non-parametric multifactorial analysis (P < 0.05).. The best results were found for irrigation with EDTA and citric acid, whereas NaOCl and water showed the least effect. The combinations of irrigants did not result in improvement in terms of cleanliness.. None of the irrigants nor their respective combinations were able to completely remove the calcium hydroxide. Chelating agents such as citric acid and EDTA showed the best results. The combination of chelators and NaOCl did not result in significant improvement of calcium hydroxide removal.

Topics: Calcium Hydroxide; Citric Acid; Edetic Acid; Humans; Incisor; Maxilla; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The objective of this study was to evaluate smear layer removal after using the new CanalBrush (Coltene/Whaledent GmbH+Co. KG, Germany).. Twenty extracted maxillary anterior teeth were randomly divided into 2 equal groups. The canals of the teeth in each group were instrumented with ProTaper Universal rotary files (Dentsply Maillefer, Switzerland). Following each file use, the root canals in both groups were irrigated with 5.25% NaOCl and 15% EDTA. At the end of instrumentation, the canals in group 2 were flushed with 15% EDTA, then a CanalBrush was used for 30 seconds, and a final irrigation was conducted with 5.25% NaOCl. All teeth were processed for scanning electron microscopy (SEM), and the removal of the smear layer was examined in the apical, middle, and coronal thirds. Analyses of SEM images were performed by 2 independent evaluators in a blinded manner and using a 4-point scoring system.. The middle and apical thirds of the root canals in group 2 showed lower average scores than those in group 1, but the difference was not statistically significant. There was no significant difference in the coronal score between the groups (P > .05).. Irrigating with brushing tended to produce cleaner canal walls, but irrigating brushing was not significantly better than irrigation alone in removing the smear layer on the canal walls.

Topics: Dental Instruments; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To evaluate the effect of different root canal irrigants on smear layer removal and dentinal tubule opening of root canal surfaces after post space preparation.. Thirty maxillary anteriors were endodontically treated. After post space preparation, the teeth were assigned to three groups with ten teeth each: group A, B, C. 3% H2O2, 15% ethylenediamine tetraacetic acid(EDTA), 15% EDTA and 3% NaClO were used as irrigant of group A, B, C. After post space irrigation, eight teeth of each group were examined under scanning electron microscope (SEM) for smear layer removal and dentinal tubule opening. The left two specimens were restored with fiber posts and prepared for evaluation of resin tag formation.. The cleansing effectiveness of group A, B and C was respectively 3.89 +/- 0.36, 1.77 +/- 0.30, 1.25 +/- 0.21. The dentinal tubule opening of group A, B and C was respectively (2.53 +/- 0.19), (3 11 +/- 023) (3.83 +/- 0.52) microm. The cleansing effectiveness and dentinal tubule opening of root canal surfaces were significantly affected by different root canal irrigants (P < 0.05). Excessive erosion of the dentin was observed in group C. Resin tag formation differed between the three irrigant groups, and group B showed excellent resin tag formation.. Irrigation with 15% EDTA after post space preparation can excellently remove the smear layer and improve dentinal tubule opening, permitting well penetration of resin adhesive into the dentinal tubules and collagen fibrillar structure.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Tooth Root

To develop a minimally destructive technique for removing the smear layer produced by cutting and polishing specimens of dentine prepared for use in experimental studies, e.g. on occlusion of dentinal tubules by oral health products. The aim was to avoid the damage caused by conventional techniques utilising short exposures to solutions with very low pH.. Two acetate buffers, pH 5.5, containing different concentrations of calcium and phosphate, with -log(ion activity product with respect to hydroxyapatite) (pI(HA)) of 55 or 56, were tested on slices of dentine using scanning electron microscopy (SEM).. A solution which, from previous work, was slightly undersaturated with respect to dentine mineral, with a pI(HA) of 56, was found to remove smear layers produced by cutting and/or polishing after 15 min. However, to reliably remove debris occluding the tubules an exposure time of 2h, followed by brief ultrasonication, was necessary. After 2h treatment with this buffer, only a small amount of demineralization of the surface was detectable by SEM, while calcium and phosphorus were detectable by X-ray dispersive spectroscopy.. It is possible to remove smear layers, and to open dentinal tubules, by a reasonably short exposure to an acidic buffer which is undersaturated with respect to dentine mineral.

Topics: Acetates; Acid Etching, Dental; Buffers; Calcium; Chemical Phenomena; Citric Acid; Dental Polishing; Dentin; Dentin Solubility; Durapatite; Humans; Hydrogen-Ion Concentration; Materials Testing; Microscopy, Electron, Scanning; Phosphates; Smear Layer; Sodium Hypochlorite; Spectrometry, X-Ray Emission; Time Factors; Tooth Preparation; Ultrasonics

The aim of this study was to verify the efficacy of doxycycline used alone or in association with sodium hypochlorite on smear layer removal. The canals of extracted human teeth were instrumented using a stepback technique. At the end of preparation, they were irrigated with doxycycline (Group 1), ethylenediaminetetraacetic acid + sodium hypochlorite (Group 2), doxycycline + sodium hypochlorite (Group 3) and water (Group 4). The dentinal wall of the cervical, middle and apical thirds was graded according to the amount of remaining debris and smear layer. The results were analysed using the Kruskal-Wallis test (P < 0.05). In Groups 2 and 4, the dentine was completely free and covered with smear layer, respectively. The results from the cervical and middle thirds of Group 3 were worse than those in Groups 1 and 2 (P < 0.05). In relation to apical third, there were differences (P < 0.05) between all groups with best results for Group 2. Doxycycline was effective in removing smear layer from cervical and middle thirds. The use of doxycycline + sodium hypochlorite was partially effective in the cervical and middle thirds, but ineffective in the apical third.

Topics: Chelating Agents; Dentin; Doxycycline; Edetic Acid; Humans; Materials Testing; Microscopy, Electron, Scanning; Needles; Odontometry; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Syringes; Tooth Apex; Treatment Outcome; Water

This study examined canal debridement efficacy by testing the null hypothesis that there is no difference between a 'Closed' and an 'Open' system design in smear layer and debris removal using either manual dynamic agitation or the EndoVac for irrigant delivery.. Forty teeth were divided into four groups and submitted to a standardized instrumentation protocol. Final irrigation was performed with either manual dynamic agitation or the EndoVac on groups of teeth with or without a sealed apical foramen. Smear and debris scores were evaluated using SEM and analysed using Cochran-Mantel-Haenszel statistic.. The ability of manual dynamic agitation to remove smear layer and debris in a closed canal system was significantly less effective than in an open canal system and significantly less effective than the EndoVac (P<0.001).. The null hypothesis was rejected; the presence of a sealed apical foramen adversely affected debridement efficacy when using manual dynamic agitation but not the EndoVac. Apical negative pressure irrigation is an effective method to overcome the fluid dynamics challenges inherent in closed canal systems.

Topics: Chelating Agents; Debridement; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Pressure; Rheology; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Suction; Therapeutic Irrigation; Time Factors; Tooth Apex; Vacuum

The objective of this study was to evaluate the sealing ability of 2 different resin-based endodontic filling systems after smear layer removal with 2 different techniques.. Extracted human single-rooted teeth (n = 74) were instrumented using HERO Shaper rotary instruments and irrigated with 1 mL of 2.5% NaOCl between each instrument. Additionally, the canals received either an extra 3-minute rinse with 2 mL of 17% EDTA or a 40-second Er,Cr:YSGG laser treatment. The root canals were filled with either Hybrid Root Seal/Resilon combination or AH Plus/gutta-percha combination using lateral condensation technique (n = 11). Apical leakage quantity was measured with the computerized fluid filtration meter at 1 and 4 weeks. One root from each group, which was not submitted to the fluid filtration test, was selected for scanning electron microscopy (SEM) analysis. Statistical analysis was performed using 3-way ANOVA and the post hoc Tukey HSD test (α = 0.05).. A significant decrease was observed in the microleakage values of all the experimental groups tested with time (P < .0001). EDTA + AH Plus/gutta-percha combination exhibited the least microleakage, whereas laser irradiation + Hybrid Root Seal/Resilon combination showed the greatest microleakage at each of the 2 time periods. Each experimental combination exhibited architecture in SEM that seemed to correlate with its sealing performance.. Er,Cr:YSGG laser treatment does not enhance the sealing ability of the sealers compared with EDTA application. The root canal adaptation and sealing ability of the Hybrid Root Seal/Resilon combination is not superior to that of the AH Plus/gutta-percha combination.

Topics: Dental Bonding; Dental Leakage; Dental Pulp Cavity; Dentin; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Lasers, Solid-State; Materials Testing; Microscopy, Electron, Scanning; Resin Cements; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors

In this ex vivo study, the surface cleanliness of root canal walls after shaping with Ni-Ti instruments and irrigating with different endodontic solutions was evaluated by SEM.. 50 single-rooted teeth were divided into 5 groups. All root canals were shaped with Revo-S™ (MICRO-MEGA®, Besancon, France) rotary Ni-Ti instruments and irrigated with NaOCl, varying the final rinse: NaOCl, Tetraclean, 17% EDTA, Cloreximid, Tetraclean liquid not mixed with powder. Specimens were fractured longitudinally and prepared for SEM analysis in order to evaluate the presence/absence of smear layer and the presence/absence of open tubules at the coronal, middle, and apical third of each canal, using a 3-step scale for scores. Numeric data were analyzed using Kruskall-Wallis test and Mann-Whitney U test and significance was predetermined at p<0.05.. This study showed significant differences between the various groups. The 5.25% NaOCl + Tetraclean and 5.25% NaOCl + 17% E.D.T.A. groups had significantly lower scores than other groups (p<0.001), with no significant difference between them.. Final rinse with Tetraclean is effective in removing the smear layer, leaving a high number of opened dentin tubules.

Topics: Anti-Infective Agents; Cetrimonium Compounds; Chlorhexidine; Citric Acid; Dental Instruments; Dental Pulp Cavity; Dentin; Doxycycline; Edetic Acid; Equipment Design; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Nickel; Polypropylenes; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Titanium

The aim of this study was to evaluate the cleaning efficacy of different irrigant agitation techniques on debris and smear layer removal in curved root canals.. Mesiobuccal root canals of 108 mandibular molars were shaped with nickel-titanium instruments, and a final rinse of NaOCl and ethylenediaminetetraacetic acid was performed. Specimens were assigned to 4 groups (n = 20) and submitted to the following irrigation agitation techniques: no agitation (control), ultrasonic, EndoActivator, and CanalBrush. Root canals were split longitudinally and subjected to scanning electron microscopy. The presence of debris and smear layer at coronal and apical levels was evaluated by using a 5-grade scoring system with 200× and 1000× magnification, respectively.. Concerning debris removal, no significant differences among groups were detected. In the coronal region, agitation of the irrigants resulted in significantly more smear layer removal than the control. EndoActivator was significantly more effective than ultrasonic agitation and CanalBrush.. In curved root canals, activation of NaOCl and ethylenediaminetetraacetic acid did not enhance debris removal but resulted in significantly more effective smear layer removal at coronal levels.

Topics: Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Therapeutic Irrigation; Vibration

The aim of this study was to reduce hybrid layer degradation created with simplified dentine adhesives by using two different methods to condition the dentine surface.. A smear-layer was created on flat dentine surfaces from extracted human third molars with a 180-grit/SiC-paper. Dentine specimens were conditioned before bonding with the following procedures: 37% H(3)PO(4); H(3)PO(4)/0.5% NaOCl; 0.1M EDTA; 0.1M EDTA/0.5% NaOCl. Two etch-and-rinse adhesives: (Scotchbond 1XT or Optibond Solo Plus) were applied and light-cured. Composite build-ups were constructed. The bonded teeth were sectioned into beams, stored in distilled water (24h) or 12% NaOCl solution (90 min) and finally tested for microtensile bond strengths (microTBS). Additional dentine surfaces were conditioned and bonded as previously described. They were prepared for a pulpal-micropermeability confocal microscopy study and finally observed using confocal microscopy.. microTBS results revealed that both adhesives gave high bond strengths to acid-etched dentine before, but not after a 12% NaOCl challenge. Bonds made to acid-etched or EDTA-treated dentine plus dilute NaOCl, gave high microTBS that resisted 12% NaOCl treatment, as did EDTA-treated dentine alone. A confocal micropermeability investigation showed very high micropermeability within interfaces of the H(3)PO(4), etched specimens. The lowest micropermeability was observed in H(3)PO(4)+0.5% NaOCl and 0.1M EDTA groups.. The use of dilute NaOCl (0.5%) after acid-etching, or the conditioning of dentine smear layers with 0.1M EDTA (pH 7.4) produced less porous resin-dentine interfaces. These dentine-conditioning procedures improve the resistance of the resin-dentine bond sites to chemical degradation (12% NaOCl) and may result in more durable resin-dentine bonds.

Topics: Acid Etching, Dental; Dental Bonding; Dental Marginal Adaptation; Dentin; Dentin Permeability; Dentin-Bonding Agents; Drug Combinations; Edetic Acid; Humans; Molar, Third; Phosphoric Acids; Resin Cements; Smear Layer; Sodium Hypochlorite; Tensile Strength

The objective of this study was to assess the influence of different final irrigating solutions on dentin permeability and smear layer removal using the same specimens and relate the results obtained.. Forty anterior human teeth were instrumented and divided into 4 groups (n = 10) at the final rinse step, according to the irrigant used: G I (control) - 1% NaOCl; G II - 17% EDTA; G III - 17% EDTAT; and G IV - Biopure MTAD. The canals were filled with 0.5% methylene blue and maintained in bottles for 48 hours. The roots were transversally split in coronal, middle, and apical fragments. The specimens were photographed and analyzed regarding dye penetration. The fragments were then axially split and prepared for SEM. The photomicrographs were analyzed and qualified by scores.. Only the EDTA-T group exhibited statistical difference in which the apical third had less dentin permeability (P < .05). When a decalcifying agent was used, smear layer was removed, which did not happen in the NaOCl group. Regarding smear layer removal, differences were found only in the EDTA group in which the apical third presented more smear layer (P < .05). No correlation was found for both studies (r = 0.4207).. There was not an even relationship between the results from both studies, which inferes that higher or lower dentinal permeability does not necessarily correspond to a higher or lower amount of smear layer. The analysis of dentin permeability and smear layer removal was shown to be a feasible procedure using the same specimens.

Topics: Citric Acid; Dental Pulp Cavity; Dentin Permeability; Doxycycline; Edetic Acid; Humans; Incisor; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

To evaluate the effects of ethylenediaminetetraacetic (EDTA), etidronic (EA) and peracetic acid (PA) when used in conjunction with sodium hypochlorite (NaOCl) as root canal irrigants on calcium eluted from canals, smear layer, and root dentine demineralization after instrumentation/irrigation.. Single-rooted human premolars were irrigated as follows (n = 12 per group): (1) 1% NaOCl during instrumentation, deionized water after instrumentation, (2) 1% NaOCl during, 17% EDTA after instrumentation, (3) a 1 : 1-mixture of 2% NaOCl and 18% EA during and after instrumentation, and (4) 1% NaOCl during, 2.25% PA after instrumentation. Irrigant volumes and contact times were 10 mL/15 min during and 5 mL/3 min after instrumentation. The evaluated outcomes were eluted calcium by atomic absorption spectroscopy, smear-covered areas by scanning electron microscopy in secondary electron mode and apparent canal wall decalcifications on root transsections in backscatter mode. For the smear layer analysis, sclerotic dentine was taken into consideration. Results were compared using appropriate parametric and nonparametric tests, alpha = 0.05.. The statistical comparison of the protocols regarding calcium elution revealed that protocol (1) yielded less calcium than (3), which yielded less than protocols (2) and (4). Most of the instrumented canal walls treated with one of the decalcifying agents were free of smear layer. Protocols (1) and (3) caused no decalcification of root dentine, whilst (2) and (4) showed substance typical demineralization patterns.. The decalcifying agents under investigation were all able to remove or prevent a smear layer. However, they eroded the dentine wall differently.

Topics: Calcium; Decalcification Technique; Dentin; Drug Combinations; Edetic Acid; Etidronic Acid; Humans; Microscopy, Electron; Peracetic Acid; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Spectrophotometry, Atomic

This study evaluated in vitro effectiveness of 17% EDTA with and without ultrasonics on smear layer removal. One hundred and five extracted premolars randomly divided into seven groups were instrumented with different final irrigating protocols: group A (Sal3US), saline for 3 minutes with ultrasonics; groups B (Na3) and C (Na3US), 1% sodium hypochlorite for 3 minutes without and with ultrasonics, respectively; groups D (ED3) and E (ED3US), 17% EDTA for 3 minutes without and with ultrasonics, respectively; and groups F (ED1) and G (ED1US), 17% EDTA for 1 minute without and with ultrasonics, respectively. Specimens were examined under scanning electron microscope and scored for smear layer and debris removal. Statistical analysis showed that groups with EDTA and ultrasonic irrigation, groups E (ED3US) and G (ED1US), had significantly more specimens with complete smear layer and debris removal. There was no significant difference between groups E (ED3US) and G (ED1US). A 1-minute application of combined use of EDTA and ultrasonics is efficient for smear layer and debris removal in the apical region of the root canal.

Topics: Bicuspid; Chelating Agents; Edetic Acid; Humans; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex; Ultrasonic Therapy

Topics: Dental Alloys; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Molar; Nickel; Retreatment; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Titanium

The purpose of this study was to evaluate the effect of different irrigating solutions on smear layer removal and dentinal tubule opening on root canal surfaces after post space preparation and to study whether additional ultrasonic irrigation has any effect on smear layer removal. Forty-eight anterior teeth were treated endodontically. After post space preparation, they were assigned to six groups: group 1, EDTA; group 2, EDTA with ultrasonic activation; group 3, sodium hypochlorite (NaOCl); group 4, NaOCl with ultrasonic activation; group 5, sodium chloride (NaCl); and group 6, NaCl with ultrasonic activation. Specimens were examined under a field-emission scanning electron microscope and scored for debris removal and dentinal tubule opening at the coronal, middle, and apical thirds of the root canal. The results showed that EDTA performed significantly better than NaCl and NaOCl in smear layer removal and dentinal tubule opening. Additional ultrasonic irrigation did not improve smear layer removal significantly.

Topics: Adult; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Middle Aged; Post and Core Technique; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Ultrasonics

The purpose of this study was to determine the effectiveness of MTAD as the final irrigant to remove the smear layer, compared with that of 17% EDTA, both following root canal irrigation with 5.25% sodium hypochlorite (NaOCl). Fifty-five extracted maxillary and mandibular single-rooted human teeth were prepared by a crown-down technique using rotary 0.04 and 0.06 taper nickel-titanium files. 5.25% sodium hypochlorite was used as the intracanal irrigant. The canals were then treated with 5 mL of one of the following solutions as final rinse: 5.25% sodium hypochlorite, 17% EDTA or MTAD. The presence or absence of smear layer in the coronal, middle and apical portion of each canal was examined with a scanning electron microscope. The results showed that MTAD is an effective final rinse solution for removing the smear layer in canals irrigated with sodium hypochlorite. When 17% EDTA was used as a final rinse, the smear layer was removed from the middle and coronal thirds of canal preparations, but it was less effective in the apical third of the canals.

Topics: Citric Acid; Doxycycline; Edetic Acid; Humans; Microscopy, Electron, Scanning; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

This study compared the efficacy of BioPure MTAD (Dentsply Tulsa, Tulsa, OK), 17% EDTA, and 42% citric acid in endodontic smear layer removal and degree of erosion in the apical third of endodontic canals.. Ninety-six extracted single-rooted human teeth were randomized into four groups (n = 24) and instrumented using System GT nickel-titanium rotary instruments (Dentsply Tulsa, Tulsa, OK). Each canal was irrigated with one of the following solutions: BioPure MTAD, 17% EDTA, 42% citric acid, or 5.25% NaOCl (control). Next, all specimens were irrigated with 5.25% NaOCl.. Evaluation by scanning electron microscopy showed no significant differences among test irrigants in removing the smear layer. However, the efficacy of BioPure MTAD and 17% EDTA in removing the smear layer was significantly greater than 5.25% NaOCl (control). The erosive effects of irrigating solutions could not be evaluated.. In conclusion, the protocols used in this study were not sufficient to completely remove the smear layer in the apical third of prepared root canals.

Topics: Adult; Citric Acid; Doxycycline; Edetic Acid; Humans; Microscopy, Electron, Scanning; Middle Aged; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Erosion; Treatment Failure

To compare the reinforcement and strengthening ability of resilon, gutta-percha, and ribbond in endodontically treated roots of immature teeth.. Sixty five freshly extracted human maxillary anterior teeth were prepared with a Peeso no. 6 to simulate immature teeth (Cvek's stage 3 root development). After instrumentation, each root was irrigated with sodium hypochlorite and with ethylene diamino tetra acetic acid to remove the smear layer. To simulate single visit apexification technique a 4-5 mm white Pro Root mineral trioxide aggregate plug was placed apically using schilder carrier. The teeth were divided into three experimental groups and one control group. Group I--control group (root canals instrumented but not filled); Group II--backfilled with thermoplastisized gutta-percha using AH plus sealer; Group III--reinforced with Resilon using epiphany sealer; Group IV--reinforced with Ribbond fibers using Panavia F luting cement. A Universal Testing Machine was used to apply a load, at the level of the lingual cementoenamel junction with a chisel-shaped tip The peak load to fracture was recorded and statistical analysis was completed using student's t-test.. Values of peak load to fracture were 1320.8, 1604.88, 1620, and 1851 newtons for Group I to Group IV respectively. The results of student's t-test, revealed no significant difference (P > 0.05,) between Group II and Group III. Comparison between Group IV and Group III and between Group IV and Group II revealed highly significant difference (P > 0.001).. Teeth reinforced with Ribbond fibers using Panavia F luting cement showed the highest resistance to fracture. Resilon could not strengthen the roots and showed no statistically significant difference when compared with thermoplastisized gutta-percha in reinforcing immature tooth when tested with universal testing machine in an experimental model of immature tooth.

Topics: Aluminum Compounds; Calcium Compounds; Composite Resins; Dental Materials; Dental Restoration, Permanent; Dental Stress Analysis; Dentin; Drug Combinations; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Oxides; Polyethylenes; Resin Cements; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silicates; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Tooth Cervix; Tooth Fractures; Tooth Root; Tooth, Nonvital

The purpose of this study was to assess the effect of different surface treatments on the shear bond strength (SBS) of a resin modified glass ionomer cement (RMGIC) to dentin.. Forty human third molar teeth were randomly divided into four groups (n=10). The occlusal enamel was removed to obtain a flat surface of dentin. Each group was treated as follows: Group 1: 10% polyacrylic acid (positive control); Group 2: 37% phosphoric acid followed by 5% sodium hypochlorite (NaOCl); Group 3: 1.1% APF gel; and Group 4: no conditioning (negative control). Fuji II LC glass ionomer was bonded to dentin using a cylindrical mold. Samples were thermocycled and debonded using a shear force with a crosshead speed of 0.5 mm/min. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey tests (a = 0.05).. The mean SBS in Groups 1 through 4 were 11.562+/-3.148, 8.060+/-1.781, 8.830+/-1.554, and 3.074+/-0.784 (MPa), respectively. There were significant differences in the SBS between Group 1 with other groups (P<0.05). There were no statistically significant differences between Groups 2 and 3, but the SBS of both of them were significantly higher than that of Group 4 (P<0.05).. Although the dentin SBS of Fuji II LC after conditioning with APF and phosphoric acid followed by NaOCl was greater than the unconditioned group (Group 4), polyacrylic acid yielded the best result.. Proper conditioning of dentin is effective in promoting close adaptation of RMGIC to dentin.

Topics: Acid Etching, Dental; Acrylic Resins; Analysis of Variance; Dental Bonding; Dental Materials; Dental Stress Analysis; Dentin-Bonding Agents; Glass Ionomer Cements; Humans; Materials Testing; Molar, Third; Phosphoric Acids; Resins, Synthetic; Shear Strength; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties

To evaluate the effect of sodium hypochlorite pretreatment on adhesion to normal and caries-affected dentin using self-etch adhesives.. Forty extracted human molars with coronal carious lesions were used in this experiment. The occlusal dentin surfaces including the caries-affected dentin in each group were treated as follows: group 1, rinsed with water; group 2, treated with 6% NaOCl for 15s; group 3, treated with 6% NaOCl for 30 s; group 4, application with Accel for 30 s after NaOCl-30 s pretreatment. After rinsing with water and air-drying, the treated dentin surfaces were applied with self-etch systems (Bond Force and Clearfil Protect Bond) according to the manufacturers' instructions, and built-up with resin composite. After 37 degrees C water storage for 24 h, the bonded normal or caries-affected dentin areas were isolated to create an hourglass configuration with a cross-sectional area of approximately 1 mm(2). The specimens were subjected to tensile stress at a cross-head speed of 1.0 mm/min.. NaOCl-15 s pretreatment significantly improved the muTBS of both self-etch adhesives to caries-affected dentin, while the 30 s pretreatment did not affect them. For normal dentin, NaOCl-30 s pretreatment significantly reduced the muTBS of both self-etch adhesives although the 15s pretreatment did not alter them. Furthermore, the application of Accel with a reducing effect increased the muTBS to normal and caries-affected dentin treated with NaOCl for 30 s.. The effects of NaOCl pretreatment on bonding of both self-etch adhesives were dependent upon type of dentin (normal and caries-affected dentin) and the treatment time.

Topics: Composite Resins; Dental Bonding; Dental Caries; Dental Etching; Dental Restoration, Permanent; Dental Stress Analysis; Dentin; Dentin Permeability; Dentin-Bonding Agents; Humans; Molar; Oxidants; Reducing Agents; Smear Layer; Sodium Hypochlorite; Tensile Strength; Time Factors

To compare the short- and long-term sealing ability of root canal fillings consisting of AH-26 and laterally compacted gutta-percha in combination with a self-etching dentin bonding system and the Epiphany-Resilon system.. Ninety-eight single-rooted human teeth were used in this study. The root canals were prepared using the step-back technique. Sodium hypochlorite 5% was used as the irrigant solution. The teeth were divided into 4 groups. In groups 1, 3, and 4, irrigation with ethylene diamine tetracetic acid (EDTA) 15% was used to remove the smear layer. In the specimens of all groups, a final irrigation with 5 ml distilled water was performed. In groups 1 and 2, the Nanobond bonding system was used. The specimens in groups 1 to 3 were obturated with AH-26 and laterally compacted gutta-percha. In the last group (4), the Epiphany-Resilon system was used. Microleakage was measured at 7 days, 1 month, and 1 year using a fluid transport model. Two specimens from each group and 4 where only Nanobond had been applied were prepared and examined in a scanning electron microscope.. The Epiphany-Resilon system and the group obturated with AH-26 sealer and gutta-percha, in combination with the self-etching bonding system after removal of the smear layer with EDTA, demonstrated similar sealing ability. Kruskal-Wallis and Mann-Whitney tests showed that he results for these two groups were statistically significanty better than the other groups (p < 0.05). All the groups examined showed increased apical leakage over time, but the increase was statistically significant after one year only in the case of the Epiphany-Resilon system.. The use of a self-etching bonding system improved the sealing ability of AH-26 sealer only after removal of the smear layer. Significantly higher microleakage over time was only observed with the Epiphany-Resilon system.

Topics: Bismuth; Dental Leakage; Dentin-Bonding Agents; Drug Combinations; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Silver; Smear Layer; Sodium Hypochlorite; Titanium

This study evaluated the effectiveness of the NaviTip FX (Ultradent Products Inc, South Jordan, UT), a 30-gauge brush-covered irrigation needle, in removing debris and smear layer in vitro.. Forty mesio-buccal maxillary and mandibular first molar root canals with 20 degrees to 30 degrees curved roots were randomly divided into four groups (n = 10). The irrigation protocol after cleaning and shaping was as follows: NaOCl/EDTA/nonbrushing (NaED) group: passive use with 5.25% NaOCl followed by 17% EDTA and saline; EDTA/brushing (EDBr) group: passive use with 5.25% NaOCl followed by left and right manual rotary up and down brushing using 17% EDTA and a saline rinse; EDTA/FileEze (Ultradent Products Inc)/brushing (EDFEBr) group: same as EDBr, however, with FileEze; and control group (CG): a standard 30-gauge NaviTip irrigation needle used passively. The roots were split longitudinally and the canals examined in a scanning electron microscope. Debris and smear layer were recorded at 1, 5, and 10 mm from the working length (WL) using a three-step scoring scale and 300-mum square grid. Mean scores were calculated and statistically analyzed (p < 0.05) between and within groups.. Comparison between groups revealed that at all evaluation levels EDBr and EDFEBr groups were significantly cleaner (p < 0.05) than NaED and CG, with no significant difference between them. Comparison within groups did not show significant differences (p > 0.05). All groups showed significantly better smear layer removal (p < 0.05) at 5 and 10 mm from the WL. The EDBr group exhibited no significant differences (p > 0.05) between the three evaluation levels.. In moderately curved root canals, a NaviTip FX used with 5.25% NaOCL and 17% EDTA solution with manual brushing as well as the same method augmented by FileEze was the most effective cleaning protocol.

Topics: Dental Pulp Cavity; Edetic Acid; Humans; Molar; Needles; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

This study evaluated in vitro the capacity of debris removal from the apical third of flattened root canals, using different final irrigation protocols. Thirty human mandibular central incisors with a mesiodistal flattened root were prepared using rotary instrumentation by Endo-Flare 25.12 and Hero 642 30.06, 35.02, 40.02 files, irrigated with 2 mL of 1% NaOCl after each file. The specimens were randomly distributed into 5 groups according to the final irrigation of root canals: Group I: 10 mL of distilled water (control), Group II: 10 mL of 1% NaOCl for 8 min, Group III: 2 mL of 1% NaOCl for 2 min (repeated 4 times), Group IV: 10 mL of 2.5% NaOCl for 8 min, and Group V: 10 mL of 2.5% NaOCl for 2 min (repeated 4 times). The apical thirds of the specimens were subjected to histological processing and 6-microm cross-sections were obtained and stained with hematoxylin-eosin. The specimens were examined under optical microscopy at x40 magnification and the images were subjected to morphometric analysis using the Scion image-analysis software. The total area of root canal and the area with debris were measured in square millimeters. Analysis of variance showed no statistically significant difference (p>0.05) among the groups GI (2.39 +/- 3.59), GII (2.91 +/- 2.21), GIII (0.73 +/- 1.36), GIV (0.95 +/- 0.84) and GV (0.51 +/- 0.22). In conclusion, the final irrigation protocols evaluated in this study using the Luer syringe presented similar performance in the removal of debris from the apical third of flattened root canals.

Topics: Dental Pulp Cavity; Dose-Response Relationship, Drug; Humans; Incisor; Mandible; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Syringes; Time Factors; Tooth Apex

To test ex vivo the efficiency of laser-activated irrigation in removing dentine debris from the apical part of the root canal and to visualize in vitro the fluid dynamics during the activation of the irrigant by laser, using high-speed imaging at a relevant timescale.. Root canals with a standardized groove in one canal wall filled with dentine debris were irrigated with syringe irrigation, ultrasonically or laser-activated irrigation (LAI) using 2% sodium hypochlorite as irrigant. The quantity of dentine debris after irrigation was determined. Visualization of the fluid dynamics during activation was achieved using a high-speed camera and a glass model.. Laser-activated irrigation was significantly more effective in removing dentine debris from the apical part of the root canal than passive ultrasonic irrigation or hand irrigation when the irrigant was activated for 20 s.. The in vitro recordings suggest that streaming, caused by the collapse of the laser-induced bubble, is the main cleaning mechanism of LAI.

Topics: Cuspid; Dental Stress Analysis; Dentin; Humans; Lasers; Microbubbles; Photography, Dental; Rheology; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Syringes; Therapeutic Irrigation; Tooth Apex; Ultrasonics

The aim of this study was to evaluate the cleaning capacity of Profile .04 files combined with different irrigating solutions in flattened root canals using histological, morphometrical and SEM analyses. Eighty human mandibular incisors were prepared with Profile .04 instruments and randomly divided into 4 groups according to the irrigating solutions used (n=20): G1: distilled water (control); G2: 1% sodium hypochlorite (NaOCl); G3: 1% NaOCl alternated with 17% EDTA, and G4: 1% NaOCl with RCPrep cream. Ten teeth of each group were evaluated with an optical microscope to determine the percentage of root canal debris. The remaining teeth were evaluated under scanning electron microscopy (SEM). Data were analyzed statistically by ANOVA and Tukey's test (alpha=0.01).There was a significant difference (p<0.001) among the groups regarding the percentage of debris left in the canals (distilled water: 18.82 +/- 5.55; 1% NaOCl: 6.29 +/- 5.55; 1% NaOCl + 17% EDTA: 12.47 +/- 6.92; 1% NaOCl + RCPrep: 7.82 +/- 1.91). The SEM analysis showed the best results for 1% NaOCl + 17% EDTA on smear layer removal. It may be concluded that the combination of Profile .04 rotary instrumentation and the tested solutions was not able to totally remove debris and smear layer from flattened root canals.

Topics: Dental Instruments; Dental Pulp Cavity; Edetic Acid; Humans; Incisor; Mandible; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Titanium

To test if the hybrid layer formation by Hybrid Root SEAL (Sun Medical Co.), a 4-META-containing auto-adhesive self-etching root canal sealer, is affected by the sequence of irrigants employed for removing canal wall smear layers during root canal treatment.. Single-rooted teeth were shaped and irrigated with EDTA as initial rinse/NaOCl as active final rinse (Group 1), or NaOCl as initial rinse/EDTA as active final rinse (Group 2). All canals were obturated with Hybrid Root SEAL using a single-cone technique. Root slices derived from the coronal, middle and apical thirds of the roots were processed for transmission electron microscopy after removing the gutta-percha, leaving the sealer intact. Additional filled canals from the two groups were evaluated for fluid leakage.. Hybrid layer was absent in Group 1 and was present only when a collagen matrix was produced by EDTA demineralization (Group 2). Significantly more leakage (4.03 +/- 1.94 microL min(-1) vs. 1.50 +/- 0.42 microL min(-1); P < 0.05) was observed in the absence of dentin hybridization.

Topics: Chelating Agents; Collagen; Dental Leakage; Dental Pulp Cavity; Dentin; Edetic Acid; Gutta-Percha; Humans; Materials Testing; Methacrylates; Microscopy, Electron, Transmission; Resin Cements; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties

The aim of this study was to evaluate the effect of using 5.25% commercial sodium hypochlorite treatment prior to the application of etch-and-rinse and self-etching adhesives on dentin surface microtopography and tensile bond strength.. Thirty-two noncarious, nonrestored human third molars were collected. The occlusal enamel of all teeth was removed using diamond disks to expose flat dentin surfaces. The exposed dentin surfaces were abraded using 600-grit SiC disks, to create a uniform dentin smear layer. For AFM characterization, 12 teeth were equally divided into 4 groups according to the proposed dentin surface treatment. Three dentin disks, 2 mm thick, were evaluated per group using tapping mode assessment. Twenty teeth were used for TBS and SEM evaluation and were equally divided into 4 groups, according to the proposed dentin surface treatment. For TBS, 8 dentin/composite slabs, 2 mm thick, were used in each group, while for SEM evaluation 2 slabs were used. Each slab was tested in tension at a crosshead speed of 0.5 mm/min until failure occurred. The samples were examined using SEM operated at 30 kv to evaluate the hybrid layer photographically at 1500X. Statistical analysis was carried out using StatsDirect 2.5.7. One-way ANOVA followed by Tukey-Kramer multiple-comparison post-hoc tests were performed to test the difference between roughness parameters and TBS between groups.. Sodium hypochlorite followed by the application of 37% phosphoric acid significantly increased the arithmetic average of the absolute values of surface height deviations (Sa), the surface area ratio which expresses the ratio between the surface area (taking the z height into account) and the area of the flat x,y plane (Sdr), and the surface bearing index (Sbi) parameters, while the application of sodium hypochlorite prior to the application of the self-etching primer significantly increased the valley fluid retention index (Svi) parameter. Self-etching primer without sodium hypochlorite pretreatment significantly increased the core fluid retention index (Sci) parameter. Sodium hypochlorite/AdheSE (7.42 +/- 2.16 MPa) significantly increased TBS value compared to other groups. However, no statistically significant difference was found between sodium hypochlorite/Excite (4.68 +/- 1.26 MPa), AdheSE (4.42 +/- 1.36), and Excite (4.06 +/- 1.35). Remnants of smear layer were detected with areas devoid of resin tags in SEM images of samples bonded with AdheSE self-etching adhesive, in contrast to samples bonded with sodium hypochlorite followed by AdheSE self-etching adhesive.. The application of 5.25% commercial sodium hypochlorite with rubbing action for 60 s (total application time 120 s) seems to positively influence the TBS of the self-etching adhesive; however, it has no significant effect on TBS of etch-and-rinse single-bottle adhesive to dentin. The addition of functional roughness parameters to study the dentin surface was shown to be of importance in evaluating the relationship between bond strength and surface topography of conditioned dentin.

Topics: Acid Etching, Dental; Acrylic Resins; Carbon Compounds, Inorganic; Composite Resins; Dental Bonding; Dentin; Dentin-Bonding Agents; Humans; Materials Testing; Methacrylates; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Oxidants; Phosphoric Acids; Photography; Resin Cements; Silicon Compounds; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Surface Properties; Tensile Strength; Time Factors

The aim of this in vitro study was to evaluate the cleaning capacity of different auxiliary chemical substances energized with ultrasound in radicular dentin using morphologic analysis.. Twenty-eight single-canal, mandibular incisors were prepared with the Hero 642 canal preparation system following the sequence: 25/12, 30/06, 35/02, and 40/02, 1 mm from the apex. The specimens were then divided into four groups of seven teeth. During biomechanical preparation the teeth were irrigated with 2 ml of distilled water between files. Each group of specimens (n=7) received a final irrigation with 100 ml of the following irrigants that were activated with ultrasound for 3 minutes: Group 1- distilled water; Group 2- 0.2% chlorhexidine digluconate (CHX); Group 3- 2.5% sodium hypochlorite (NaOCl); and Group 4-the filtrate obtained after combining 0.2% CHX and 2.5% NaOCl. The apical portions of the root canals from each group were then submitted to histological processing and analyzed using optical microscopy.. Results showed statistical differences between the groups (p<0.01). Groups 1 and 2 (distilled water and 0.2% CHX respectively) were statistically similar in terms of a greater amount of debris, whereas 2.5% NaOCl and the filtrate were more efficient in removal of debris.. There is no additional benefit in terms of debris removal from root canal walls by irrigating with the filtrate obtained from the combination of NaOCl and CHX when compared to using NaOCl alone.. The findings of this study suggest the time and expense of preparing and using a combination of NaOCl and CHX is not warranted compared to using NaOCl alone for root canal irrigation.

Topics: Chlorhexidine; Drug Combinations; Humans; Incisor; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy

The purpose of this study was to evaluate whether irrigation times of 1 minute or less with 1 mL of 17% ethylene diamine tetra-acetic acid (EDTA) effectively removed the smear layer from root canals after rotary instrumentation. Forty single-canal teeth were decoronated, instrumented, and divided into 3 experimental groups (n = 10). Ten teeth served as positive and negative controls. The experimental groups received a final rinse with 1 mL of 17% EDTA for 1 minute, 30 seconds, or 15 seconds followed by a final 3-mL rinse with 6% NaOCl. Teeth were split longitudinally and prepared for scanning electron microscopy imaging. Digital images (350x) of the approximate center of the coronal, middle, and apical sections were graded for quality of smear layer removal by 3 endodontists. Data were analyzed with nonparametric tests, with significance level set at alpha = .05. Significantly greater smear layer removal was found in the 1-minute EDTA irrigation group than the 30-second or 15-second groups.

Topics: Bicuspid; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Therapeutic Irrigation; Time Factors

The purpose of this study was to evaluate the amounts of debris and smear layer remaining on canal walls after preparation with ProTaper and Hero Shaper instruments in combination with NaOCl and EDTA irrigation in curved root canals.. A total of 55 root canals were randomly divided into 2 instrumentation groups of 20 canals each and 1 negative control group of 15 canals. The canals in each of the 2 instrumentation groups were prepared with ProTaper or Hero Shaper instruments. Irrigation was performed with 5% NaOCl and 17% EDTA solutions. The control group was not instrumented. The remaining debris and smear layer were evaluated from scanning electron photomicrographs at x200 and x1,000 magnification taken in the coronal, middle, and apical thirds of the canals at both inner and outer canal walls. A 5-category scoring system for debris and smear layer was used. Statistical analysis was carried out using the Kruskal-Wallis and Mann-Whitney rank sum tests.. Completely clean root canals were not found in either instrumentation group. In the coronal and middle thirds, the canal walls of both instrumentation groups were clean, with no or only small areas of debris and smear layer. In the apical region, there were higher scores in terms of debris and smear layer in both instrumentation groups. No significant difference was found at the inner wall of the 2 instrumentation groups in terms of debris mean score. However, the outer canal walls prepared with ProTaper showed lower debris score compared with those prepared with Hero Shaper (P < 0.001). Concerning the smear layer, both the inner and outer canal walls prepared with ProTaper showed lower mean scores compared with those prepared with Hero Shaper (P < 0.001).. Within the limitations of this study, both instruments in combination with NaOCl and EDTA irrigation produced a clean and debris-free canal surface in the coronal and middle thirds, but were unable to produce a canal surface free from debris and smear layer in the apical third. However, the canals prepared with ProTaper instruments showed smaller amounts of debris and smear layer remaining in the apical region.

Topics: Edetic Acid; Humans; Microscopy, Electron, Scanning; Molar; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric

The aim of this study was to observe the colonization pattern of C. albicans on treated and untreated radicular dentin.. Root sections of 10 human mandibular premolar teeth were longitudinally separated into halves. The 20 halves were separated into 2 groups and each half served as its own control. In Group 1, only gross pulpal remnants were removed with pliers. Root canal walls in the corresponding 102 halves (Group 2) were instrumented with Gates-Glidden burs and treated with sequential use of 15% EDTA solution for 3 minutes and 2.5% NaOCl solution for 3 minutes. Finally, all teeth were washed with distilled water. Each specimen was placed individually in each well of a 24-well cell culture plate. After the assembly was sterilized with ethylene-oxide, the root canal of each specimen was inoculated with 20 microL of C. albicans (1-1.5 x 10(6) cfu/mL) that was kept in place for 24 hours for initial attachment. Then, 2 mL of SDB was added to each well and the assembly was placed in an incubator at 37 degrees C for 10 days. Following the incubation period, the specimens were washed, fixed, dehydrated, and processed for scanning electron microscopy.. C. albicans was present on the root canal surfaces of all specimens; however, the colonization pattern was different. In the untreated group, the main growth pattern was a dense mass of yeast cells forming biofilm layers while hyphal structures were not common. On the other hand, pseudohyphae invaded all root canal surfaces in Group 2 and yeast cells were occasionally observed.. The treatment procedures of root canal dentin have a strong influence on the colonization pattern of C. albicans. This fact should be considered when planning and evaluating in vitro Candida adhesion and/or penetration studies.

Topics: Candida albicans; Cell Adhesion; Colony Count, Microbial; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Hyphae; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

This study is a retrospective analysis of the outcome of initial nonsurgical root canal treatment of teeth with open apices, obturated with mineral trioxide aggregate when no apical barrier existed. One hundred sixteen patients from a single private endodontic office were treated between 1999 and 2006. Treatments on 144 teeth were completed either in one (92/144) or two visits with an interim calcium hydroxide interappointment medication (52/144). Fifty-four percent (78/144) of the teeth were available for recall (60.3% one visit and 39.7% two visits). The maximum time to recall was 4.87 years. The mean time to recall was 19.4 months. Of the cases recalled for period of 1 year or longer, 93.5% of teeth treated in 1 visit healed, and 90.5% of teeth treated in 2 visits healed.

Topics: Adolescent; Adult; Aged; Aluminum Compounds; Anti-Infective Agents, Local; Calcium Compounds; Calcium Hydroxide; Chelating Agents; Child; Chlorhexidine; Drug Combinations; Edetic Acid; Female; Follow-Up Studies; Humans; Male; Middle Aged; Oxides; Periapical Diseases; Retrospective Studies; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Silicates; Smear Layer; Sodium Hypochlorite; Tooth Apex; Treatment Outcome; Young Adult

To investigate dentinal tubule invasion and the predilection of Enterococcus faecalis for dentinal tubule walls.. The invasion of dentinal tubules in extracted human teeth by E. faecalis was measured ex vivo after 8 weeks of incubation. The canal walls of 16 root sections were either intact or instrumented with or without smear layer present. Extent and maximum depth of tubule invasion were assessed histologically and compared between groups. In the adherence study, 44 vertically split root samples were prepared to expose longitudinally aligned dentinal tubules and fractured orthodentine (OD). Surfaces were exposed to E. faecalis (erythromycin resistant strain, JH2-2 carrying plasmid pGh9:ISS1) and incubated aerobically for 2 h. Samples were processed for analysis using scanning electron microscopy. Bacterial adhesion to tubule walls versus fractured OD was calculated as number of cells per 100 microm(2).. The strain of E. faecalis used in this study showed moderate to heavy tubule invasion after 8 weeks. In the adhesion studies, significantly more bacteria adhered to fractured OD than to dentinal tubule walls (ANOVA, P < 0.001). With respect to the tubule wall, adherence was greater in inner versus outer dentine (P = 0.02) and greater when bacterial adhesion was tested in chemically defined medium than in phosphate-buffered saline (ANOVA, P < 0.001).. Although E. faecalis readily invaded tubules, it did not adhere preferentially to tubule walls. Initial colonization of dentinal tubules by E. faecalis may depend primarily on other factors.

Topics: Bacterial Adhesion; Colony Count, Microbial; Dental Pulp Cavity; Dentin; Enterococcus faecalis; Gamma Rays; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sterilization

The aim of this study was to assess, by scanning electron microscopy analysis, the cleaning ability of irrigants and auxiliary chemical substances in biomechanical preparation. Thirty-two single-rooted human teeth were subjected to standardized root canal instrumentation with different irrigants (n = 8): group 1, 2.5% NaOCl + 17% ethylenediaminetetraacetic acid (EDTA); group 2, 2% chlorhexidine gel + 17% EDTA; group 3, Canal Plus + 2.5% NaOCl; group 4, saline + 17% EDTA. After instrumentation, the teeth were prepared for scanning electron microscopy analysis (2000x) to evaluate the cleaning of cervical, middle, and apical thirds. The area analyzed was quantified according to the percentage of open tubules, and data were statistically analyzed by analysis of variance and Tukey tests (P = .05). The results showed statistically significant difference with higher quantity of open tubules in groups 1 and 3. In all groups, the cleaning obtained on the cervical third was better than that obtained on the middle and apical thirds, with statistically significant difference in the chlorhexidine group. Irrigation with Canal Plus in combination with NaOCl and NaOCl followed by EDTA produced greater cleaning of the root canal walls.

Topics: Chelating Agents; Chlorhexidine; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

To evaluate the effect of Carisolv as chemical reagent on root canal cleanness in chemomechanical preparation.. Sixty extracted teeth which were dyed with methylene blue were randomly divided into 3 groups, different chemical reagents were applied in different groups. The optical density of methylene blue in irrigating solution were measured with UV-VIS spectrophotomer after preparation with each file, the root canal cleanness was evaluated under SEM. Two-way ANOVA and Kruskal-Wallis H test in SPSS 11.5 software package were used for statistical analysis.. There were significant differences in the optical density between the root canals treated with Carisolv and those with 2% tosylchloramide sodium plus 3% hydrogen peroxide (P<0.05), no significant difference was found in optical density between the root canals treated with Carisolv and those with 2.5% sodium hypochlorite (P>0.05). The results of SEM were consistent with those of the optical density of methylene blue.. As a chemical reagent, the cleaning ability of Carisolv was as effective as 2.5% sodium hypochlorite. Carisolv can remove the smear layer and debris, without causing excessive demineralization. Supported by Key Research Project of Science and Technology Committee of Liaoning Province(Grant No.00225001).

Topics: Dental Pulp Cavity; Disinfectants; Glutamic Acid; Humans; Leucine; Lysine; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Smear Layer; Sodium Hypochlorite

To study the effect of the smear layer on the penetration of bacteria along different root canal filling materials and to examine the dentine/sealer and sealer/core material interfaces for the presence of bacteria.. A total of 110 human root segments were instrumented to size 80 under irrigation with 1% sodium hypochlorite. Half of the roots were irrigated with a 5-mL rinse of 17% EDTA. Roots with and without smear layer were filled with gutta-percha (GP) and AH Plus sealer (AH), GP and Apexit sealer (AP), or RealSeal cones and sealer (RS). Following storage in humid conditions at 37 degrees C for 7 days, the specimens were mounted into a bacterial leakage test model for 135 days. Survival analyses were performed to calculate the median time of leakage and log-rank test was used for pairwise comparisons of groups. The level of significance was set at P = 0.05. Selected specimens were longitudinally sectioned and inspected by scanning electron microscopy for the presence of bacteria at the interfaces.. In the presence of the smear layer, RS and AP leaked significantly more slowly than in its absence. In the absence of the smear layer, AH leaked significantly more slowly than RS. SEM results indicated a differential pattern of bacterial penetration among the sealers.. Removal of the smear layer did not impair bacterial penetration along root canal fillings. A comparison of the sealers revealed no difference except that AH performed better than RS in the absence of the smear layer.

Topics: Bacteria; Calcium Hydroxide; Chelating Agents; Composite Resins; Dental Leakage; Dental Pulp Cavity; Dentin; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Surface Properties; Temperature; Time Factors; Water

The combination of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) forms a precipitate. The aim of this study was to evaluate the effect of irrigating root canals with a combination of NaOCl and CHX on root dentin and dentinal tubules by using the environmental scanning electron microscope (ESEM) and a computer program (Photoshop CS2). Forty-four extracted single-rooted human teeth were instrumented and irrigated with both NaOCl and CHX to produce a precipitate. Root canal surfaces were analyzed with the ESEM. The amount of remaining debris and number of patent tubules were determined. There were no significant differences in remaining debris between the negative control group and the experimental groups. There were significantly fewer patent tubules in the experimental groups when compared with the negative control group. The NaOCl/CHX precipitate tends to occlude the dentinal tubules. Until this precipitate is studied further, caution should be exercised when irrigating with NaOCl and CHX.

Topics: Anti-Infective Agents, Local; Chemical Precipitation; Chlorhexidine; Dental Pulp Cavity; Dentin; Drug Interactions; Humans; Image Processing, Computer-Assisted; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The purpose of this study was to compare in vitro the amount of debris and irrigant extruded apically from extracted teeth, using manual technique and crowndown pressureless technique by K3, RaCe, and FlexMaster instruments.. Sixty human single-rooted mandibular premolar teeth were randomly assigned to 4 groups, 15 teeth each. The teeth in 4 groups were instrumented until the working length with RaCe, K3, FlexMaster, and K-type stainless steel instruments respectively. Debris and irrigant extruded from the apical foramen were collected into vials and the amounts were determined. The data obtained were analyzed using Kruskal-Wallis 1-way analysis of variance and Mann-Whitney U tests, with alpha = 0.05 as the level for statistical significance.. No statistically significant difference was observed among the groups in terms of debris extrusion (P > .05). On the other hand, a statistically significant difference was observed between K3 and manual technique groups in terms of irrigant extrusion (P < .05). The difference between other groups was not statistically significant (P > .05).. Based on the results, all instrumentation techniques produced extruded debris and irrigant; however, the engine-driven nickel-titanium systems were associated with less apical extrusion and irrigant.

Topics: Analysis of Variance; Bicuspid; Dental Alloys; Dental Instruments; Extravasation of Diagnostic and Therapeutic Materials; Humans; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Titanium; Tooth Apex

To evaluate and compare ex vivo the decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine.. Two 2-mm-thick slices were cut from the coronal third of the root of 10 human incisors. Each slice was sectioned into two equal parts. Specimens were assigned to one of four groups (n = 10) for immersion in 20 mL of either 15% EDTA, or 15% citric acid, 5% phosphoric acid or 2.5% NaOCl, for three time periods (5, 10 and 15 min). The concentration of Ca(2+) extracted from the dentine was measured by atomic absorption spectrophometry. The amount of calcium extracted was analysed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons.. In the three time periods, 15% EDTA and 15% citric acid extracted the largest amount of calcium, with no significant differences between them. The 2.5% NaOCl solution extracted insignificant amounts of calcium, whereas 15% EDTA extracted 86.72% of the calcium in the first 5 min, and 15% citric acid and 5% phosphoric acid had a similar pattern of calcium removal (77.03% and 67.08% in first 5 min, respectively).. Solutions of 15% EDTA, 15% citric acid and 5% phosphoric acid decalcify root dentine, with most calcium extracted during the first 5 min of action. The efficacy of 15% citric acid and 15% EDTA solutions was significantly greater than that of 5% phosphoric acid solution at each time period (5, 10 and 15 min).

Topics: Adult; Calcium; Citric Acid; Decalcification Technique; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Incisor; Middle Aged; Phosphoric Acids; Regression Analysis; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Spectrophotometry, Atomic; Statistics, Nonparametric

To determine the microtensile bond strength (microTBS) of one- and two-step self-etch adhesives bonded to sound dentin conditioned or not with phosphoric acid (H3PO4) and sodium hypochlorite (H3PO4 + NaOCl).. Extracted human third molars had their crowns transversally sectioned to expose flat dentin surfaces that were divided into four groups, and bonded as follow: (1) according to the manufacturers' directions, (2) acid etched with 36% H3PO4, and (3) 10% NaOCl treated for 2 minutes, after H3PO4 etching. Two two-step self-etching primers (Clearfil SE Bond/SEB and Resulcin/RE), and two one-step adhesives (One-Up Bond F/OUB and Etch & Prime 3.0/EP) were examined. Composite build-ups were constructed incrementally with Tetric Ceram. The specimens were stored in humidity for 24 hours at 37 degrees C and sectioned into beams of 1.0 mm2 cross-sectional area. Each beam was tested in tension in an Instron machine at 0.5 mm/minute, and mean microTBS data (MPa) were analyzed by 2-way ANOVA and post-hoc multiple comparisons tests (P < 0.05).. The two-step adhesive SEB exhibited the highest bond strength when bonded to smear layer-covered dentin, whereas RE was not affected by all dentin surface conditions. H3PO4 and H3PO4 + NaOCl pretreatments significantly increased bonding efficacy of the one-step adhesives OUB and EP, respectively.

Topics: Acid Etching, Dental; Composite Resins; Dental Bonding; Dentin; Dentin-Bonding Agents; Ethanol; Humans; Humidity; Materials Testing; Methacrylates; Oxidants; Phosphates; Phosphoric Acids; Resin Cements; Smear Layer; Sodium Hypochlorite; Stress, Mechanical; Surface Properties; Temperature; Tensile Strength; Time Factors

To compare the efficacy of three irrigation protocols using an established ex vivo bio-molecular film model.. Thirty human teeth with single straight canals were randomly allocated to three groups [static, manual-dynamic, automated-dynamic (RinsEndo]; each with a sub-group (n = 5) for needle position at 4 or 10 mm short of the working length (WL). The root canals were prepared to apical size 40, taper 0.08. The teeth were split longitudinally into two halves and a standard coat of stained-collagen was applied to the canal surfaces. The re-assembled teeth were irrigated using one of the protocols with the irrigation needle at one of two positions. Digital images of the canal surfaces, before and after irrigation with 18 mL of 2.5% NaOCl, were used to score surface coverage with stained-collagen using image-analyses (ipWin4). The data were analysed using linear regression models.. The canal area covered with stained-collagen was significantly (P < 0.001) less after dynamic irrigation (manual/automated) compared with static irrigation; but automated-dynamic irrigation was significantly (P = 0.037) less effective than manual-dynamic irrigation. The 'orientation of needle port', 'corono-apical level of canal' and 'apical extent of needle placement' were significant (P < 0.001) factors influencing efficacy of irrigation. Residual collagen was most evident in the coronal third. Deeper penetration of the needle tip resulted in significantly (P < 0.001) more effective collagen removal.. Automated-dynamic irrigation was significantly more effective (16%) than static irrigation but significantly less effective (5%) than manual-dynamic irrigation. Irrigation was more effective (7%) when the needle was placed closer to WL.

Topics: Biofilms; Collagen; Dental Pulp Cavity; Humans; Image Processing, Computer-Assisted; Linear Models; Models, Biological; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

To evaluate ex vivo the effects of combined and single use of EDTA, RC-Prep and NaOCl on the surface free energy of canal wall dentine using the captive bubble technique.. Eighteen extracted human pre-molar teeth were sectioned at the crown and the apical third, the remaining mid-root portion were bisected longitudinally. Thereafter, the root halves were embedded in resin blocks that exposed the dentine surface of the canal wall. The specimens were randomly assigned to six experimental groups (n = 6) after polishing. The root dentine surfaces of the first two groups were treated with 17% EDTA or RC-Prep followed by 2.5% NaOCl irrigation. Groups 3, 4 and 5 were treated with either 17% EDTA, RC-Prep or 2.5% NaOCl alone. Control specimens were irrigated with saline solution. The surface free energies of experimental groups were calculated by measuring air and octane contact angles on the canal wall dentine. Statistical analysis was performed using the Mann-Whitney U and Bonferroni post-tests at P = 0.05.. Compared with the control group; combined and single use of EDTA, RC-Prep and NaOCl irrigation significantly decreased the surface free energy of canal wall dentine surfaces (P < 0.05). Among all groups tested, the use of NaOCl as a final flush following RC-Prep treatment yielded increased wettability. Nevertheless, this value remained lower than that of the control group.. Use of chelating agents alone or in combination with NaOCl decreased the wettability of root canal wall dentine.

Topics: Bicuspid; Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Peroxides; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties; Urea; Waxes; Wettability

The aims of this in vitro study were to evaluate debris and smear layer elimination capability effectiveness of 5.25% sodium hypochlorite (NaOCl) after calcium hydroxide removal from the root canal and to determine if ethylenediaminetetraacetic acid (EDTA) and citric acid have any additional effects on debris and smear layer removal.. All irrigation regimens are associated with ultrasonics. Thirty-six pulpless single-rooted teeth were divided into three groups on the basis of the irrigation regimen, namely 5.25% NaOCl alone, 5.25% NaOCl with 17% EDTA pH 7 (NaOCl-EDTA), and 5.25% NaOCl with 50% citric acid (NaOCl-CA). All root canals were instrumented with the Protaper rotary system (Dentsply-Maillefer, Ballaigues, Switzerland) using a crown-down approach. The apical foramen of each tooth was enlarged to a size 30 with a 0.09 taper. After longitudinal sectioning, the dentin walls were microphotographed using scanning electron microscopy (SEM) at a 1500x magnification. Using a grid and a 5-step scale these microphotographs were scored by three investigators in order to evaluate debris and smear layer residuals. Data were statistically evaluated using Kruskal-Wallis and Mann-Whitney tests.. In the coronal third the lowest score obtained with NaOCl-CA was similar to NaOCl-EDTA. When using NaOCl-EDTA, mean debris scores were similar to the control group (NaOCl) and lower than NaOCl-CA in the middle and apical thirds. Regarding the mean smear layer score, NaOCl-CA was the lowest in the coronal, middle, and apical thirds with a statistically significant difference (p < 0.001).. When the total surface of the root was evaluated, NaOCl-EDTA was superior in removing debris, but the association of NaOCl-CA enabled the most effective removal of the smear layer.

Topics: Calcium Hydroxide; Citric Acid; Drug Combinations; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric

Cleaning the root canal is not possible without using proper irrigation. The aim of this in vitro study was to evaluate the effect of MTAD as a final irrigant on bacterial leakage of the root canal, and its interaction with two conventional root canal sealers. We used 132 extracted human maxillary anterior teeth. The teeth were randomly divided into three experimental groups (n=40) and two groups (n=6) of positive and negative control. In group 1, the smear layer was not removed and irrigation was performed using 5.25% NaOCl. In group 2, the smear layer was removed using EDTA, and in group 3, the smear layer was removed using MTAD according to the clinical protocol of use. The teeth in each group were obturated with gutta-percha and AH-Plus or Rickert sealer. The coronal portion of each root was placed in contact with inoculum of Streptococcus mutans in Brain Heart Infusion (BHI) culture media. Each root tip was placed in one bottle containing sterile BHI. Mean duration of bacterial penetration in groups 2 and 3 was significantly greater than in group 1, but there was no significant difference between groups 2 and 3. According to our findings, it takes longer for bacteria to penetrate when either EDTA or MTAD is used for smear layer removal. The root canals obturated with AH Plus showed significantly longer duration of resistance to bacterial penetration than canals obturated with Rickert.

Topics: Analysis of Variance; Citric Acid; Dental Leakage; Doxycycline; Edetic Acid; Epoxy Resins; Humans; Incisor; Polysorbates; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite; Streptococcus mutans

The purpose of this in vitro study was to compare the efficacy of 24% ethylenediaminetetraacetic acid (EDTA) gel and 17% EDTA solution in cleaning dentine walls after root canal instrumentation. Thirty human canine teeth were divided into three groups of 10 teeth each. In Group 1, 1% sodium hypochlorite was used as the irrigating solution; in Group 2, 1% sodium hypochlorite was used with 17% EDTA solution; and in Group 3, 1% sodium hypochlorite was used with 24% EDTA gel. The presence of a smear layer was analysed after instrumentation using scanning electron microscopy. The Kruskal-Wallis test revealed a statistical difference (P < 0.05) between Groups 1 and 2, and also between Groups 1 and 3. No difference was observed between Groups 2 and 3 (P > 0.05). The results indicate that 1% sodium hypochlorite alone does not remove the smear layer and that there was no statistical difference between EDTA gel and EDTA solution in smear layer removal.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Gels; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Solutions

The use of calcium-depleting solutions in restorative dentistry results in demineralization of intact coronal dentin beneath smear layers. Likewise, application of calcium-depleting irrigants as final rinses might create demineralized collagen matrices in intact radicular dentin after removal of root canal wall smear layers created during canal shaping. These unsupported collagen matrices collapse on desiccation and might be difficult to detect in scanning electron microscopy dehydration techniques traditionally used in endodontic research. Demineralized collagen matrices were identified, by using a hexamethyldisilazane dehydration protocol, on the surface of smear layer-depleted radicular dentin when NaOCl was used as initial rinse, followed by the use of 17% ethylenediaminetetraacetic acid or BioPure MTAD as the final rinse. Compaction of conventional root filling materials over a demineralized collagen matrix in instrumented dentin is analogous to performing the same procedure against the predentin collagen network in the uninstrumented parts of root canals. The potential consequences of this process are, however, unknown.

Topics: Calcium; Citric Acid; Collagen; Dentin; Doxycycline; Edetic Acid; Humans; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

To evaluate the effectiveness of a new root canal irrigation technique with intracanal aspiration in removing the smear layer and to assess irrigant extrusion ex vivo.. Thirty-five instrumented canals of extracted human canine teeth that had been resected apically by removing 3 mm of the root tip were divided into one control and four experimental groups of seven teeth each. The roots were fixed in a plastic case and surrounded with normal saline agar coloured with 1% acid red. No irrigation was performed in the control teeth. Each root canal in the experimental groups was irrigated with 9 mL of 14% ethylenediaminetetraacetic acid for 3 min, and then with 6 mL of 6% sodium hypochlorite (NaOCl) for 2 min. In the intracanal aspiration technique, the irrigant was delivered from the tip of an injection needle placed 12 mm from the apical root-end and an aspiration needle that was connected to a Root ZX apex locator placed 2 and 3 mm short of the apical root-end in groups 1 and 2, respectively. In the conventional method, the tip of an injection needle used for delivery of the irrigant and as an active electrode was placed 2 and 3 mm short of the apical root-end in groups 3 and 4, respectively, the tip of the aspiration needle was placed 12 mm from the apical root-end in these groups. The readings of the Root ZX during irrigation were recorded. The cleanliness of the canal was evaluated by scoring smear layer from scanning electron microscopy (SEM) images of the canal. Extrusion of NaOCl was detected by measuring the discoloured area of the agar around the apical root-end. The data obtained were statistically analysed by one-way anova, the Kruskal-Wallis test and Friedman's test.. In the SEM study, the canals in groups 1-3 were significantly cleaner than those in the control and group 4 (P < 0.05). The mean Root ZX readings in groups 1-3 were approximately "0.5". The discoloured area in group 3 was significantly larger than the other groups (P < 0.05).. Irrigation using the intracanal aspiration technique allowed more effective removal of the smear layer than that performed by the conventional method in an apically resected canine tooth. The intracanal aspiration technique produced limited extrusion of the irrigant beyond the apical foramen.

Topics: Apicoectomy; Chelating Agents; Coloring Agents; Cuspid; Dentin; Disinfectants; Edetic Acid; Humans; Microscopy, Electron, Scanning; Needles; Odontometry; Pressure; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Suction

The structure of mechanically instrumented intraradicular dentin after irrigation with NaOCl as the initial rinse and BioPure MTAD as the final rinse were examined from the coronal, middle, and apical parts of root canal walls using transmission electron microscopy. Sterile distilled water and EDTA as final rinses were employed as the respective positive and negative controls under the same experimental conditions. There were 2 to 5 mum thick smear layers produced on mechanically instrumented root canal walls that were completely removed by EDTA and BioPure MTAD under agitation. Both irrigants created a zone of demineralized collagen matrices in eroded dentin and around the dentinal tubules, with the mildly acidic BioPure MTAD being more aggressive than EDTA. These demineralized dentin zones create the opportunity for dentin hybridization by infiltration of hydrophilic adhesives/sealers. However, the potential consequences of compaction of hydrophobic sealers against air-dried, collapsed collagen matrices, and hydrolytic degradation of incompletely infiltrated matrices remain unresolved.

Topics: Bicuspid; Citric Acid; Collagen; Dental Bonding; Dental Pulp Cavity; Dentin; Dentin Permeability; Doxycycline; Edetic Acid; Humans; Microscopy, Electron, Transmission; Polysorbates; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Demineralization

The purpose of this study was to evaluate the ultramorphological and chemical changes in Er,Cr:YSGG laser-treated radicular dentin in comparison with two different irrigation regimes. Extracted human premolars were assigned into three experimental groups. Group 1: After each file size, root canals were irrigated with 5.25% NaOCL, followed by a final irrigation with 5.25% NaOCL. Group 2: At each file size, biomechanical preparation was performed in conjunction with Rc-Prep, followed by 5.25% NaOCL irrigation; and 5.25% NaOCL for the final flush. Group 3: 5.25% NaOCL was used after each file size, followed by Er,Cr:YSGG laser irradiation; and a final flush with 5.25% NaOCL. Scanning electron microscopic (SEM) evaluations revealed failure of smear removal in NaOCL-irrigated specimens. RC-Prep + NaOCL-treated dentin revealed moderate-to-total presence of the smear layer with distinct areas of exposed collagen. Er,Cr:YSGG laser irradiation of radicular dentin also resulted in partial or total removal of the smear associated with a few small regions of thermal injury, including carbonization and partial melting. Energy dispersive X-ray analysis (SEM-EDX) showed no significant difference between the Ca/P ratios of the test groups, suggesting absence of changes at the molecular level.

Topics: Bicuspid; Calcium; Chromium; Dentin; Electron Probe Microanalysis; Erbium; Humans; Laser Therapy; Magnesium; Phosphorus; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric

To assess the bond strength of the new resin-based Epiphany-Resilon root canal filling system, and to compare this with bond strengths of different pairings of AH Plus, gutta-percha, Epiphany and Resilon.. A total of 65 extracted human single-rooted teeth were used. All teeth were instrumented using a set of ProTaper rotary instruments. Irrigation was performed with 15 mL of 1.25% NaOCl between each instrument and the smear layer was removed during and after instrumentation with 5 mL of 17% EDTA. The canal spaces were filled with different combinations of core and sealer using lateral condensation, as follows: group 1, AH Plus + gutta-percha; group 2, AH Plus + Resilon; group 3, Epiphany + Resilon; group 4, Epiphany + gutta-percha; group 5 (control), gutta-percha only. Cylinders of root dentine 1.13 (0.06)-mm long were prepared from the coronal sections of the 65 teeth. The test specimens were subjected to the push-out test method. After adhesion testing, the remaining sections were examined under a stereomicroscope at x 25 magnification to determine the nature of bond failure. The values of bond strength were analyzed by one-way analysis of variance (ANOVA) and the post hoc Tukey's test, with significance set at P < 0.05.. The respective mean push-out test values for groups 1-5 were: 2.000 +/- 0.369, 1.380 +/- 0.154, 1.706 +/- 0.340, 2.857 +/- 0.523 and 0.078 +/- 0.027 MPa. Significant difference (P < 0.001) occurred between the groups. Multiple paired comparisons (Tukey's test) revealed that group 4 (Epiphany + gutta-percha) had significantly (P < 0.001) greater bonding strength than all the other groups; group 1 (AH Plus + gutta-percha) had significantly (P < 0.05) greater bonding strength than group 2 (AH Plus + Resilon); and group 5 (control) had significantly (P < 0.05) lower bonding strength than all the other groups. Inspection of the surfaces revealed the bond failure to be mainly adhesive to dentine for all groups.. The Epiphany-Resilon combination (group 3) was not superior to that of the AH Plus-gutta percha combination (group 1).

Topics: Chelating Agents; Dental Bonding; Dental Stress Analysis; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stress, Mechanical

To evaluate the effectiveness of Carisolv and different auxiliary chemical substances in root canal smear layer (SL) removal. SL was produced in the centre of 40 hemi-disks of bovine root dentine. The samples were divided into four irrigation groups (G): GI (control) - 0.9% NaCl; GII - 1% NaOCl + 0.9% NaCl; GIII - Carisolv + 0.9% NaCl; GIV - 1% NaOCl + 10% citric acid solution + 0.9% NaCl. The photomicrographs (SEM analysis) were coded (0 - absence of SL; 1 - moderate SL; 2 - dense SL with visible tubules; 3 - dense SL with no visible tubules). GIV was more effective in SL removal (P < 0.01). It should be noted that GI and GIII obtained score 3 in 100% of the samples (P > 0.01).. NaOHCl, citric acid and NaCl solutions, when used together, presented a better performance in the removal of SL when compared to the other solutions.

Topics: Animals; Cattle; Citric Acid; Glutamic Acid; Leucine; Lysine; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Statistics, Nonparametric

There are no quantitative data on the mechanical efficacy of irrigation in the removal of bacteria from curved canals. This study quantitatively analyzed the effects of root canal curvature and preparation size on the mechanical efficacy of irrigation using 33 mandibular single-rooted bicuspids allocated to groups according to root canal curvatures, group 1 (straight) 4 to 8 degrees, group 2 (intermediate curvature) 15 to 19 degrees, and group 3 (greatest curvature) 24 to 28 degrees. Teeth were sequentially instrumented to sizes 27/.04, 36/.04, and 46/.04 using a crown-down technique. Suspensions of the bioluminescent reporter strain Pseudomonas fluorescens 5RL (1.5 x 10(6) cells) were inoculated into canals of sterilized teeth after each sequential instrumentation. Canals were irrigated with 6 ml of irrigant delivered 1 mm from working length using a 30-gauge needle. Remaining bacteria were quantified using real-time bioluminescent imaging. Irrigation was significantly less effective in 24 to 28 degrees curvature canals prepared to size 27/.04 compared to 46/.04 (p < 0.007, repeated-measures ANOVA).

Topics: Bicuspid; Chelating Agents; Colony Count, Microbial; Dental Pulp Cavity; Edetic Acid; Humans; Image Processing, Computer-Assisted; Luminescence; Pseudomonas fluorescens; Radiography, Dental, Digital; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Spectrophotometry

To compare in vitro the cleanliness of root canal walls following automated or manual instrumentation.. Thirty extracted human maxillary central incisors, maxillary and mandibular canines and premolars with single root canals were used in this study. The teeth were divided into two groups. In group 1 (20 teeth) automated canal preparation was performed using Anatomic Endodontic Technology (AET). In group 2 (10 teeth) manual instrumentation was performed with K-Flexofiles. Irrigation was performed using alternately 3.00% NaOCl and 18% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined using a scanning electron microscope. The presence of debris and smear layer was recorded at coronal, middle and apical thirds of root canals using a four-step scoring scale. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P<0.05) between and within groups, using the Mann-Whitney-Wilcoxon and Friedman nonparametric tests.. At coronal and middle thirds the root canals prepared with manual instrumentation had significantly less surface debris on the canal walls compared with canals prepared with AET (p<0.05). At apical third root canals prepared with manual instrumentation had significantly more debris compared with AET group. The amount of smear layer was greater in the apical than in the coronal and middle thirds of the root and significantly less amount was in the AET group (P<0.05).. Complete cleanliness was not achieved by any of the techniques and instruments investigated. It may be inferred that the choice between AET and hand instrumentation should be based on factors other than the amount of root canal debridement, which does not vary high significantly according to the instruments used.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Equipment Design; Humans; Materials Testing; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Tooth Apex

The cleaning capacity of rotary Ni-Ti instrumentation using Profile GT files, coupled with irrigation energised by ultrasound, was evaluated. Thirty-six human mandibular incisors were instrumented in vitro using the crown-down technique with the Profile GT system to 1 mm from the anatomical apex to a size 30.04 taper file. The instrumented teeth were then divided randomly into four groups where various final irrigations were used: Group I: 100 ml of 1% NaOCl with a Luer-Lok syringe (control group); Group II, Group III and Group IV: final irrigation with 100 ml of 1% NaOCl energised by ultrasound for 1, 3 and 5 min, respectively. After biomechanical preparation, the apical thirds of the roots were submitted to histological processing and examination. The specimens were analysed at 40x magnification and the images submitted to morphometric analysis with an integration grid. anova showed a statistically significant difference (P < 0.01) between the irrigation techniques. Group I (Luer-Lok syringe) showed the highest percentage of debris (35.81 +/- 4.49) and was statistically different from the other groups energised by ultrasound: Group II (27.28 +/- 4.49), Group III (24.39 +/- 5.72) and Group IV (18.46 +/- 5.25). It was concluded that rotary instrumentation using Ni-Ti files associated with final irrigation of 1% NaOCl energised by ultrasound leads to better debris removal from the apical third of mesio-distally flattened root canal.

Topics: Analysis of Variance; Dental Alloys; Dental Instruments; Humans; Incisor; Mandible; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Syringes; Titanium; Ultrasonic Therapy

The aim of this study was to evaluate, in vitro, the ability of an 8% EDTA solution to remove debris and smear produced during root canal preparation.. Single-rooted human teeth were used for this experiment. All root canals were instrumented in a similar fashion and irrigated with a 3.5% NaOCl solution. The teeth were divided into 6 groups. According to the groups, various final flushes were performed with a 15% or 8% EDTA solution for 1 or 3 min and with or without saline rinsing. After preparation, roots were separated into 3 thirds and each third was observed by SEM. Debris (D) and root canal smear (S) was evaluated twice.. The results were subjected to ANOVA. The D and S scores for all test groups were statistically different from the control group without EDTA flush (P = .0001). The lowest D and S scores were obtained by a 3 min rinse with 8% EDTA solution and a statistical difference was observed in the apical third (P < .05).. Under these in vitro conditions, 3 min 8% EDTA irrigation is as effective as 1 min 15% EDTA irrigation.

Topics: Analysis of Variance; Chelating Agents; Dental Pulp Cavity; Dentin; Dose-Response Relationship, Drug; Edetic Acid; Humans; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Water

To verify, under the scanning electron microscope (SEM), the influence of irrigation time with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) on intracanal smear layer removal.. Twenty-one extracted human permanent teeth with single straight root canals were included. The root canals of the teeth were instrumented and, at the end of preparation, were irrigated with 3 mL of 15% EDTA, followed by 3 mL of 1% NaOCl for 1 min (group 1), for 3 min (group 2), and for 5 min (group 3). The canals of teeth in group 4 (control) did not receive the final irrigation. The teeth were sectioned longitudinally and prepared for an SEM. The dentinal wall of cervical, middle and apical thirds was graded according to the amount of debris and smear layer remaining on the walls. The results were analysed using the Kruskal-Wallis and Conover-Inman tests.. In all the canals of experimental groups irrigation with EDTA and NaOCl completely removed the smear layer from the cervical and middle thirds. In the apical third, the dentine surface were partially covered, particularly in the teeth of group 1, where there was significantly more smear layer when compared with the other thirds in the same group (P<0.007). However, the Kruskal-Wallis test showed overall that there were no significant differences between groups 1, 2 and 3 (P>0.05).. In this limited laboratory study, canal irrigation with EDTA and NaOCl for 1, 3 and 5 min were equally effective in removing the smear layer from the canal walls of straight roots.

Topics: Chelating Agents; Cuspid; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors; Tooth Apex; Tooth Cervix

The purpose of this study was to compare the efficacy of Er,Cr:YSGG laser in root canal preparation and its effectiveness in removing debris and smear layer with the efficacy of the conventional hand instrument, in vitro.. Recently, the use of the Er,Cr:YSGG laser device in root canal preparation has been excepted in the dental clinic. However, there have been no published reports on root canal preparation by using the Er,Cr:YSGG laser irradiation.. A total of 40 straight root canals were prepared by an Er,Cr:YSGG laser at a output power of 2 W, and 40 canals were shaped by using the K file under irrigation with NaOCl and H2O2 by using the crown-down technique (control). The achievement degree of root canal preparation and debris score was morphologically investigated.. The results showed that great improvement in the cleanliness of the walls was found using the laser technique as compared with the control technique; a significant decrease in smear layer or debris was also recognized in laser-prepared canals (p < 0.01). But canal preparations with the laser device sometime result in ledge, zipped, perforation, or over-instrumentation.. The results demonstrated that root canal preparations with the laser device were significantly worse than in the control group. Further development in laser device and technique are required to ensure its success in root canal preparation.

Topics: Anti-Infective Agents, Local; Case-Control Studies; Dental Pulp Cavity; Dentin; Disinfectants; Humans; Hydrogen Peroxide; In Vitro Techniques; Laser Therapy; Microscopy, Electron, Scanning; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Tooth Root

To compare in vitro the cleanliness of root canal walls in oval-shaped root canals following automated or manual instrumentation.. Forty-five oval-shaped single-rooted maxillary and mandibular premolars with straight canals were divided into three groups of 15. Automated canal preparation was performed using Anatomic Endodontic Technology (AET, group 1) and the ProFile system (group 2). Manual instrumentation (group 3) was performed with K-Flexofiles. Irrigation was performed using alternately 5.25% NaOCl and 17% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined at x200 and x400 in a scanning electron microscope. The presence of debris and smear layer was recorded at distances of 1, 5 and 10 mm from the working length using a three-step scoring scale and a 300 mum square grid. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P < 0.05) between and within groups, using the Kruskal-Wallis nonparametric anova and Dunn's tests.. At 1, 5 and 10-mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls compared with canals prepared with ProFile or manual instrumentation. For all three groups significantly lower mean smear layer scores (P < 0.05) were recorded at 5 and 10-mm levels compared with the 1 mm level. Significantly lower mean debris scores (P < 0.05) were also recorded at 5 and 10-mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile and manual instrumentation groups.. Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved by any of the techniques and instruments investigated.

Topics: Analysis of Variance; Bicuspid; Dental Instruments; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric

To test the null hypothesis that Carisolv is no more effective than 1% sodium hypochlorite in cleaning uninstrumented, immature root canals.. A total of 240 uniform, immature ovine incisors were decoronated at the CEJ level and randomly divided into four groups of 60. After gross pulp extirpation, canals were flooded with normal saline (negative control), 1% NaOCl, Carisolv or 5% NaOCl (positive control) and incubated for 10 min (group 1), 20 min (group 2), 30 min (group 3) or 30 min, refreshing irrigant at 10 and 20 min (group 4). SEM photomicrographs of canal wall debris in the apical, middle and coronal thirds were scored against a 5-point scale. Internal consistency was assessed by kappa statistics. Debris scores for different irrigant regimes at different canal levels were analysed by non-parametric tests (P < 0.05).. Canals were consistently cleaner in the coronal and middle than apical thirds. NaOCl (5%) was consistently most effective. Carisolv and NaOCl (1%) were no more effective than normal saline in group 1 (P > 0.05), but significantly more effective than normal saline in groups 2 (middle and apical 1/3), 3 and 4 (P < 0.05). Carisolv and NaOCl (1%) had comparable activity in groups 1, 2 (middle and apical thirds) and 3, but NaOCl (1%) was significantly more effective than Carisolv in group 4 (coronal and middle thirds).. 1. The ovine incisor model presents opportunities to investigate irrigation regimes under controlled ex-vivo conditions. 2.NaOCl (5%) remains the most effective irrigant for rapid debris removal in immature root canals. 3. Carisolv cleans pulp debris from the walls of immature root canals as effectively as NaOCl (1%) during static, unrefreshed wall contact for between 20 and 30 min. 4. Refreshment of NaOCl (1%) enhances its cleaning ability above that of Carisolv.

Topics: Animals; Dental Pulp Cavity; Glutamic Acid; Leucine; Lysine; Materials Testing; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Sheep; Sheep, Domestic; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Tooth Root

To investigate the influence of the taper of root canals on the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris.. Forty-four maxillary and mandibular canines were selected after bucco-lingual and mesio-distal radiographs indicated that their internal diameters were smaller than the diameters of a size 20, .06 taper System GT instrument (Dentsply Maillefer, Ballaigues, Switzerland). These canines were divided into three groups and prepared using either size 20, .06 taper System GT instruments, size 20, .08 taper or size 20, .10 taper System GT instruments. Each root was then split longitudinally through the canal, forming two halves. In one canal wall, a standard groove was cut 2-6 mm from the apex, to simulate un-instrumented canal extensions. Each groove was filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in the un-instrumented canal extensions. Each canal was reassembled by joining the two halves of the teeth by means of wires and sticky wax. In each canal ultrasonic irrigation was performed with a size 15 K file using 2% NaOCl as an irrigant. Before and after irrigation, images of each half of the canal with a groove were taken using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris. The scores before and after irrigation were compared. The differences in percentage of score reduction between the three groups were analysed by means of one-way anova.. After ultrasonic irrigation, the debris score reduced by 74, 81 and 93%, respectively, in the size 20, .06, 20, .08 and 20, .10 taper groups. However, the difference amongst groups was not statistically significant (P = 0.078).. There was a tendency that ultrasonic irrigation was more effective in removing artificially placed dentine debris from simulated canal extensions from canals with greater tapers.

Topics: Analysis of Variance; Cuspid; Dental Instruments; Dental Pulp Cavity; Dentin; Humans; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Ultrasonics

To test an aqueous gel containing 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) regarding its interactions with sodium hypochlorite, its calcium binding capacity, and its potential in preventing the formation of a smear layer when used in conjunction with rotary root canal preparation.. The experimental aqueous gel consisted of (w/v) 2% alginate, 3% aerosil, 10% Tween 80 and 18% HEBP. Interactions of gel components with hypochlorite were assessed using iodometric titration and monochromatic ultraviolet spectrometry. Two commercial paste-type chelators containing ethylenediaminetetraacetic acid (EDTA) and peroxide (RC-Prep and Glyde) served as controls. Calcium-binding capacities were measured in mixtures with a Ca2+ standard solution buffered at pH 10 using a calcium-selective measuring chain. Finally, root canals of 16 extracted single-rooted premolars per group were instrumented using ProFile instruments dipped in the experimental gel, RC-Prep, or nothing. Additionally, canals were rinsed with 10 mL of a 1% NaOCl solution during/after preparation. Smear scores in instrumented teeth were monitored using scanning electron microscopy.. None of the experimental gel components showed short-term interactions with hypochlorite, whilst EDTA, peroxide, RC-Prep and Glyde immediately reduced the hypochlorite in solution. The experimental gel chelated 30 mg Ca2+ g-1, compared with 16 mg Ca2+ g-1 and 11 mg Ca2+ g-1 chelated by RC-Prep and Glyde respectively. Smear scores obtained with the experimental gel were significantly (P<0.05) lower than with RC-Prep in coronal and middle root thirds, whilst no differences were observed in apical root thirds.. Under the conditions of this study, an HEBP gel appeared advantageous over currently available products.

Topics: Calcium; Chelating Agents; Dental Pulp Cavity; Edetic Acid; Etidronic Acid; Gels; Humans; Materials Testing; Peroxides; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Spectrophotometry, Ultraviolet; Titrimetry; Urea; Waxes

The aim of this study was to assess interactions of EDTA and citric acid (CA) with sodium hypochlorite (NaOCl), the indispensable endodontic irrigant. Other chelators were simultaneously evaluated as possible alternatives: sodium triphosphate (STP), amino tris methylenephosphonic acid (ATMA), and 1- hydroxyethylidene-1, 1-bisphosphonate (HEBP). Available chlorine was titrated in chelator-NaOCl solutions. All chelators other than HEBP and STP caused an almost complete, immediate loss of available chlorine in solution. Atomic absorbtion spectrometry and SEM evaluation of root canal walls of instrumented teeth indicated that NaOCl had no negative effect on calcium-complexing ability of chelators. STP was too weak a complexing agent to warrant further studies. Finally, CA-, EDTA-, and HEBP-NaOCl mixtures were evaluated for their antimicrobial capacity. Again, EDTA and CA negatively interfered with NaOCl, while HEBP did not.

Topics: Anti-Infective Agents, Local; Calcium; Chelating Agents; Chlorine; Citric Acid; Dental Pulp Cavity; Edetic Acid; Enterococcus faecalis; Etidronic Acid; Humans; Microscopy, Electron, Scanning; Organophosphorus Compounds; Polyphosphates; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Spectrophotometry, Atomic

The efficacy of solutions to remove the smear layer from human teeth was evaluated. One and 2.5% sodium hypochlorite, 1 and 5% calcium hydroxide, 0.2% (solution) and 2% (gel) chlorhexidine gluconate, 1% tea and distilled water as control were assessed. Fifty-six freshly extracted permanent human incisors were selected. Access cavities, conductometric measurements and apical sealing with wax were performed. Root canals were instrumented up to a #40 file at the apical level and with the step-back technique up to #60 file and irrigated with 25 ml of each solution. Roots were longitudinally cut and cleaning of dentinal walls in the coronal, middle and apical thirds was evaluated by scanning electron microscopy. The ANOVA test showed no statistically significant differences between the thirds treated with the same solution (p = 0.562), but showed differences between solutions (p = 0). Although none of the solutions showed complete elimination of the smear layer, sodium hyplochlorite solutions were the most efficientfollowed by calcium hydroxide solutions and chlorhexidine. Tea and distilled water were less effective.

Topics: Calcium Hydroxide; Chlorhexidine; Dental Pulp Cavity; Dentin; Humans; Incisor; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tea; Tooth Apex; Water

The tendency to fracture of human teeth has been attributed to numerous reasons, including pulpless tooth dehydration, tooth structure degeneration, and excessive spreader loading. To date, however, no consistent data has been gathered to ascertain the effect of organic tissue on the biomechanical properties of human dentin. This study explored the influences of organic tissue removal on the morphological changes and punch shear strength by means of low vacuum wet scanning electron microscope (Wet-SEM) and punch shear apparatus.. The crown dentin slices with a thickness of 0.45-0.50 mm were prepared from extracted human molars. These specimens were immersed in 5% NaOCl for 1, 3, and 6 h to remove the organic tissue. The dynamic morphological changes of these dentin slices after immersion were observed using Wet-SEM. In addition, the punch shear strength and stiffness of specimens were measured.. The removal of organic tissue by 5% sodium hypochlorite treatment caused many cracks on the specimen surfaces. Intertubular and peritubular dentin were also affected, causing an abnormal configuration of dentinal tubule orifices. The 5% sodium hypochlorite treatment for 1, 3, and 6 h significantly reduced the punch shear strength of dentin. As the immersion time increased, the values of punch shear strength also diminished.. The organic tissue loss of human dentin would affect the structure of intertubular and peritubular dentin and cause many cracks on the dentin surface. The punch shear strength of human dentin also reduced after removal of organic tissue.

Topics: Chondroitin Sulfates; Collagen Type I; Dental Stress Analysis; Dentin; Glycosaminoglycans; Humans; Linear Models; Microscopy, Electron, Scanning; Molar; Shear Strength; Smear Layer; Sodium Hypochlorite

The aim of this study was to evaluate, in vitro, with scanning electron microscope (SEM), the appearance of root canal walls shaped by three different rotary NiTi techniques and one conventional manual technique in human extracted teeth. Four different instruments were used: K3, Hero 642, RaCe and K-file. Each sample was irrigated with 5 ml of 5% NaOCl and 5 ml of 3% H2O2 and EDTA, Rc-Prep (1 ml). Each sample was prepared for SEM observation and analyzed in the coronal, middle and apical third, comparing its aspect with a predefined scale of four different parameters: presence of smear layer, pulpal debris, inorganic debris and surface profile. The apical third showed significantly more pulpal and inorganic debris, smear layer and a high number of surface profile irregularities. No significant difference was found at the coronal, middle and apical thirds between manual and rotary techniques for inorganic debris, smear layer and surface profile. Much pulpal debris were found in the apical third for K3 and RaCe compared with Hero 642 and K-file. In conclusion, mechanical rotary techniques with NiTi instruments produced quite similar results compared with a conventional manual technique using K-files. The present study demonstrated that dentin and pulpal debris, the morphology of smear layer and surface profile were only partially influenced by the type of endodontic instruments. The apical third was the anatomical area with greater amount of debris and smear layer.

Topics: Analysis of Variance; Dental Alloys; Dental Pulp; Dental Pulp Cavity; Dentin; Equipment Design; Humans; Microscopy, Electron, Scanning; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Titanium; Tooth Apex

To investigate the influence of diameter and taper of root canals on the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris from simulated uninstrumented extensions in simulated root canals.. Three groups of standard canals were cut in resin blocks using either size 20, .04 taper ProFile instruments, size 20, .06 Greater Taper (GT) rotary instruments or size 20, .08 GT instruments, respectively. Each resin block was then split longitudinally through the canal, forming two halves. In one canal wall, a standard groove 4 mm in length was cut 2-6 mm from the apical end of the canal, to simulate uninstrumented canal extensions. Each groove was filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in the uninstrumented canal extensions. Each canal was reassembled by joining the two halves of the resin block by means of wires and sticky wax. In each canal ultrasonic irrigation was performed for 3 min using 2% NaOCl as irrigant. Before and after irrigation, images of each half of the canal with a groove were taken using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris remaining. The score data were analysed by means of Kruskal-Wallis and Mann-Whitney U-tests.. After ultrasonic irrigation, the debris score for the size 20,.04 taper group was significantly higher than that for the size 20,.06 group (P = 0.040) and the size 20,.08 group (P = 0.006) groups. However, no significant difference was found between the size 20,.06 and the size 20,.08 groups (P = 0.320).. In simulated plastic root canals, the diameter and taper of root canal influenced the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris.

Topics: Dental Instruments; Dentin; Models, Structural; Resins, Synthetic; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Therapeutic Irrigation; Ultrasonics

The aim of this study was to examine the morphology of the hybrid layer (HL) of bonded water-stored specimens after different chemical pre-treatments of dentin.. Twenty-seven recently extracted human molars were selected. Fifty-four dentin disks in middle/deep dentin were obtained with a slow speed saw with a diamond-impregnated disk under water lubrication. Smear layers were created with 180 grit silicon carbide under running water for 1 min. Different pre-treatments of dentin were: Group (1) no treatment; Group (2) 35% H3PO4 etch for 15 s followed by 10% glutaraldehyde for 120 s; Group (3) 37% H3PO4 etch for 15 s followed by 5% NaOCl for 120 s. Three dentin bonding agents (DBAs), Prime and Bond NT (P and B), AdmiraBond (AB), and Clearfil SE Bond (SEB) were applied in association with a resin composite following the manufacturers' directions. Each specimen was then longitudinally sectioned and polished with wet SiC papers (up to #4000 grit). Impressions of the polished dentin were immediately taken with a silicone impression material. Bonded specimens were then stored for 3 or 12 h in deionized water. Further impressions of stored specimens were taken after air-drying of specimens for 10 s. Positive replicas were obtained using a polyether impression material. All the replicas and the original specimens were inspected by SEM.. A line of droplets (0.5-4 microm in diameter) was observed along the region of the adhesive-HL junction in all replicas of specimens stored in water, except in group 3, when P and B and AB were used. When SEB was used in each group the droplet were found in all groups except the zone of droplets was thinner. No differences in droplets dimensions were seen between 3 or 12 h water storage, or between the different dentin treatments.. The replica procedure used in this study was able to detect water trapped in the adhesive-HL region that was released during the setting of the impression material. The droplets observed in this region support the hypothesis that there can be bidirectional water movement within the adhesive-HL complex.

Topics: Acid Etching, Dental; Adsorption; Dental Bonding; Dental Impression Technique; Dentin; Dentin Permeability; Dentin-Bonding Agents; Fibrillar Collagens; Glutaral; Humans; Molar; Polymethacrylic Acids; Random Allocation; Replica Techniques; Resin Cements; Smear Layer; Sodium Hypochlorite; Water

The aim of the present study was to evaluate the deproteination potential of 5% aqueous NaOCl solution applied by rubbing action on the molecular composition and morphology of smear-layer covered and acid-etched human coronal dentin surfaces.. Paired specimens (n = 4 x 2 per group) of acid-etched (Group A) and smear-layer covered (Group B) human coronal dentin surfaces were sequentially treated with the NaOCl solution for time intervals ranging from 5 s to 120 s and analyzed by reflectance FTIR microspectroscopy and tapping mode atomic force microscopy. The changes in the mineral (v4 P-O stretching vibrations) to matrix (C = O stretching vibrations of amide I) peak area ratios and in the Ra roughness parameter were used to quantify the effect of treatment. Two-way ANOVA and Dunn's tests were used to assess the differences within each group and between groups (a = 0.05).. In both groups, NaOCl treatment reduced organic matrix (amide I, II, III peaks), but did not affect carbonates and phosphates. In group A, the rate of deproteination was slow, and reached a peak value after 120 s. Tubule orifices became visible after 40 s of treatment; after 120 s, excessive porosity was detected, with Ra values presenting no statistically significant difference from group B. In group B after 10 s, the extent of deproteination was enhanced, reaching a plateau between 30 s and 60 s, and attaining a maximum after 120 s. Tubule diameter, intertubular porosity, and Ra were increased; intertubular dentin area was reduced. For both groups after 40 s of treatment, the mineral to matrix ratio recorded was similar to smear-layer-free sectioned dentin.. The results of the present study imply that deproteination of mineralized or acid-etched dentin surfaces within a clinically relevant time frame may provide methods for bonding to dentin alternative to conventional technique-sensitive dentin hybridization.

Topics: Acid Etching, Dental; Dental Bonding; Dentin; Dentin Permeability; Dentin-Bonding Agents; Friction; Humans; Materials Testing; Microscopy, Atomic Force; Molecular Structure; Proteins; Smear Layer; Sodium Hypochlorite; Spectroscopy, Fourier Transform Infrared; Surface Properties; Tooth Crown

To compare using scanning electron microscopy (SEM) root canal walls following instrumentation in vitro with two different rotary NiTi instruments. The hypothesis was that no difference should be observable between the experimental groups in terms of debris on canal walls and surface morphology.. Twenty-four single-rooted human teeth were selected. Two types of NiTi instruments were used, Mtwo (Sweden & Martina, Padova, Italy) and ProTaper (Dentsply Maillefer, Ballaigues, Switzerland). Irrigation for both groups was performed after each instrument change with 5% NaOCl, 3% H2O2 and 17% EDTA solutions. Three different areas (coronal, middle and apical thirds) of the root canal were evaluated using SEM. The canal wall of each sample was assessed and compared using a predefined scale of four parameters, namely, smear layer, pulpal debris, inorganic dentine debris, surface profile. Data were analysed statistically using the Kruskal-Wallis test (anova).. A statistically significant difference (P < 0.01) was found between the apical third and the middle and coronal thirds for both groups. No difference was observable between instrumentation groups. In the apical third canal walls were often contaminated by inorganic debris and by smear layer. In the apical third, the surface profile was affected by uninstrumented regions, comprising dentine depressions and grooves in which predentine was still visible.. Both instruments produced a clean and debris-free dentine surfaces in the coronal and middle thirds, but were unable to produce a dentine surfaces free from smear layer and debris in the apical third. The presence of deep grooves and depression on dentine walls in the apical third may well explain the presence of less-instrumented areas.

Topics: Chelating Agents; Dental Alloys; Dental Pulp; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Humans; Hydrogen Peroxide; Materials Testing; Microscopy, Electron, Scanning; Nickel; Oxidants; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Titanium; Tooth Apex

The purpose of this study was to evaluate the effect of smear-layer removal using MTAD on coronal leakage of obturated root canals using a dye-leakage test. Fifty, extracted, single-rooted, human teeth were cleaned and shaped and divided into 5 equal groups of 10 each. The smear layer in groups 1 to 3 was left intact. The smear layer in groups 4 and 5 was removed using 17% EDTA or MTAD, respectively. After obturation of root canals, the access opening to each canal was filled with India ink for 48 h. The depth of coronal-dye penetration was measured using the Sigmascan software. ANOVA showed statistically significant differences among the groups (p < 0.05). Samples treated with MTAD yielded significantly less leakage than samples treated with sodium hypochlorite. The amount of dye penetration was not statistically different between teeth treated with MTAD or EDTA (p = 0.062).

Topics: Analysis of Variance; Citric Acid; Dental Leakage; Dental Pulp Cavity; Doxycycline; Edetic Acid; Humans; Polysorbates; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite; Tooth Crown

Various solutions used to irrigate root canals and remove the smear layer prior to obturation of a root canal affect surface topography and may influence the sealing ability of endodontic therapy, retention of endodontic dowels, and restoration survival.. This study microscopically evaluated the effects of varying dilutions of lactic acid on the removal of the smear layer created by hand instrumentation in the coronal, middle, and apical thirds of root canals. Lactic acid solution was compared with other solutions deemed to be suitable root canal irrigants.. Thirty-five extracted human single-rooted teeth were manually shaped with files (K-flex) using the step-back technique. ISO size 50 files were used as master apical files. The teeth were equally divided into 7 test groups according to the canal irrigant used. While the teeth were cleaned and shaped, the root canals were irrigated with 3 mL of 1 of the following irrigants between each file size and as a final flush: no irrigant (control), 5% hydrogen peroxide, 5% sodium hypochlorite, a combination of 5% hydrogen peroxide and 5% sodium hypochlorite, 15% ethylenediaminotetraacetic acid (EDTA), 10% lactic acid, or 20% lactic acid. Specimens were critical-point dried and freeze-fractured for scanning electron microscope analysis at 3 sites (cervical, middle, and apical).. Scanning electron micrographs showed no differences between the cervical, middle, and apical levels of the specimens tested with any of the irrigants used. Also, no difference was found within individual groups. The surface of the control specimens had a smear layer that contained smear plug material. Hydrogen peroxide and sodium hypochlorite used separately and in combination consistently produced surfaces with a smear layer. Lactic acid solutions and EDTA, however, removed the dentinal smear layer but left remnants of smear plugs in the dentinal tubules.. Within the limitations of this study, differences related to the type of irrigant used were found in the characteristics of the pulpal dentin surface. Although lactic acid effectively cleaned and smoothed the dentin walls of root canals of endodontically prepared teeth, further study is needed before this procedure can be recommended for routine clinical use.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Dentin Permeability; Edetic Acid; Humans; Hydrogen Peroxide; Lactic Acid; Microscopy, Electron, Scanning; Pilot Projects; Post and Core Technique; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

Various organic acids, ultrasonic instruments, and lasers have been used to remove the smear layer from the surface of instrumented root canals. The purpose of this study was to investigate the effect of various concentrations of sodium hypochlorite (NaOCl) as an intracanal irrigant before the use of MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) as a final rise to remove the smear layer. Ten operators, using a combination of passive step-back and rotary 0.04 taper, nickel-titanium files, prepared 80 single- and multirooted human teeth. Distilled water, four different concentrations of NaOCl, or MTAD was used as intracanal irrigant. The canals were then treated for 2 min with 5 ml of one of the following solutions as a final rinse: 5.25% NaOCl, sterile distilled water, 17% EDTA, or MTAD. The presence or absence of smear layer and the amount of erosion on the surface of the root canal walls at the coronal, middle, and apical portion of each canal were examined under a scanning electron microscope. The results show that although MTAD removes most of the smear layer when used as an intracanal irrigant, some remnants of the organic component of the smear layer remain scattered on the surface of the root canal walls. The effectiveness of MTAD to completely remove the smear layer is enhanced when low concentrations of NaOCl are used as an intracanal irrigant before the use of MTAD as a final rinse. This regimen does not seem to significantly change the structure of the dentinal tubules.

Topics: Anti-Bacterial Agents; Chelating Agents; Chi-Square Distribution; Citric Acid; Dentin; Detergents; Doxycycline; Drug Combinations; Edetic Acid; Humans; Microscopy, Electron, Scanning; Odds Ratio; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

To compare several parameters of root canal preparation using two different rotary nickel-titanium (Ni-Ti) instruments: FlexMaster (VDW, Munich, Germany) and HERO 642 (Micro-Mega, Besançon, France).. Fifty extracted human mandibular molars with root canal curvatures between 20 and 40 degrees were embedded into a muffle system. All root canals were prepared to size 45 using a high-torque motor with two different Ni-Ti instruments, FlexMaster and HERO 642. In both groups, irrigation was performed with 2 mL NaOCl (3%) after each instrument size. RC-Prep (Premier, Philadelphia, USA) was used as a chelating agent with each instrument. The following parameters were evaluated: straightening of curved root canals, postoperative root canal diameter, working safety (file fractures, perforations, apical blockages, loss of working length), cleaning ability and working time. Statistical analysis was performed using the Wilcoxon's test (P < 0.05) for straightening and Fishers's exact test (P < 0.05) for comparison of cross-sections, contact between pre- and postoperative diameter, root canal cleanliness and working time.. Both Ni-Ti systems maintained the curvature well: the mean degree of straightening was 0.6 degrees for FlexMaster and 0.5 degrees for HERO 642. One file was fractured with the FlexMaster system, but further procedural incidents were not recorded. Following preparation with FlexMaster, 18% of the root canals had a round diameter, 53% an oval diameter and 29% an irregular diameter; HERO 642 preparations resulted in a round diameter in 25%, oval shape in 47% and irregular cross-sections in 28% of the cases. Mean working time was shorter for HERO 642 (66.0 s) than for FlexMaster (71.1 s). Cleanliness of the root canal walls was investigated under the SEM using 5-score indices for debris and smear layer. For debris, HERO 642 and FlexMaster achieved 73 and 70% scores of 1 and 2, respectively. The results for smear layer were similar: HERO 642 and FlexMaster achieved 33 and 26% scores of 1 and 2, respectively. Significant differences between the two systems were not detected for any of the parameters evaluated.. Both systems respected original root canal curvature well and were safe. Both systems failed to remove debris and smear layer in the majority of the cases.

Topics: Chelating Agents; Dental Alloys; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Equipment Design; Equipment Failure; Equipment Safety; Humans; Microscopy, Electron, Scanning; Nickel; Peroxides; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Time Factors; Titanium; Torque; Urea; Waxes

Necrotic bovine pulp and dentin were used in this study as model tissues to represent the organic and inorganic components of the smear layer present in instrumented root canals. The capabilities of endodontic irrigants to dissolve pulverized forms of these tissues were compared. Lyophilized tissue samples were mixed for 2 h at 37 degrees C with MTAD, three concentrations of sodium hypochlorite (NaOCl), 17% EDTA, or isotonic saline. Undissolved tissues were rinsed with water and lyophilized. The change in tissue weight after exposure to an irrigant was measured to quantify solubilization. The results showed that various concentrations of NaOCl removed organic components of pulp and dentin effectively. As pulp solubilizers 5.25% and 2.60% NaOCl were equal (>90%), and 5.25% NaOCl was capable of dissolving virtually the entire organic component of dentin. EDTA was capable of solubilizing inorganic material in dentin and organic material in pulp and likely also in dentin. It dissolved >70% of the dentin and >51% of the pulp. The solubilizing effects of MTAD on pulp and dentin were somewhat similar to those of EDTA. The major difference between the actions of these solutions was a high binding affinity of doxycycline present in MTAD for the dentin.

Topics: Animals; Cattle; Citric Acid; Dental Pulp; Dentin Solubility; Doxycycline; Edetic Acid; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Solubility

The design of the cutting blade of rotary instruments may affect the outcome of root canal instrumentation in terms of cleanliness. The aim of this scanning electron microscopic study was to compare the quality and amount of smear layer generated in the apical third of straight root canals by 2 rotary nickel-titanium reamers and 1 rotary steel reamer with different cutting blade designs.. Seventy intact, single-rooted human mandibular premolars with straight, fully developed roots were selected for this study. Before instrumentation, the cervical portion of all teeth was removed by using a microtome (Isomet), leaving 13-mm-long roots. Automated preparation was performed with ProFile (n = 20) and Hero 642 (n = 20) reamers by using the crown-down technique and with a stainless steel engine reamer (Mani; n = 20) by using a reaming motion. All root canals were instrumented to No. 40. A control group (pulp extirpation with barbed broaches; n = 10) was also included. Irrigation with 3 mL of a 1% sodium hypochlorite (NaOCl) solution was performed after each instrumentation. After the instrumentation, each root was split longitudinally, and a scanning electron microscope was used to examine the selected areas of the canal walls at the apical third from 2 different perspectives. A 4-category scoring system for smear layer was used, and the resulting scores were statistically analyzed.. The least smear layer remained in the Hero 642 group at the selected apical third of straight root canals (P < .05). However, all instruments left a smear layer. The surface texture of the smear layer, in addition to the depth and the frequency of packed materials into the dentinal tubules, varied with instrument type.. These data revealed that the design of the cutting blade of rotary instruments can affect root canal cleanliness in straight root canals. This information may be useful in the selection of nickel-titanium rotary reamers.

Topics: Dental Alloys; Dental Pulp Cavity; Dentin; Equipment Design; Humans; Microscopy, Electron, Scanning; Nickel; Pulpectomy; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stainless Steel; Surface Properties; Titanium; Tooth Apex

The smear layer associated with endodontic instrumentation is currently thought to be a thin layer that occludes the orifices of the dentinal tubules and covers the intertubular dentin of the prepared canal wall. The purpose of this study was to compare the effect of ethylene glycol bis (beta-amino ethyl ether)-N, N, N', N'-tetra acetic acid (EGTA) and ethylene diamine tetra acetic acid (EDTA) on removal of the smear layer through the scanning electron microscopy. Twenty four single rooted teeth were selected, instrumented and irrigated with various solutions and the specimens were processed for scanning electron microscopy. It was found that though both EGTA and EDTA completely removed the smear layer, EDTA caused erosion and conjugation of the tubules, whereas, EGTA effectively removed the smear layer without inducing any erosion. It was thus concluded that EGTA can be effectively used as an alternative chelator for the removal of the smear layer.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Egtazic Acid; Humans; Incisor; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Previous studies have shown that MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) is an effective antibacterial irrigant as a final rinse to remove the smear layer from the instrumented surface of root canals. In this investigation we examined the cytotoxicity of MTAD compared with that of commonly used irrigants and medications. L929 fibroblasts were grown on cell culture plates and were placed in contact with various concentrations of test irrigants and medications. The cytotoxicity of these materials was evaluated 24 h after incubation using MTT assay. Means and standard deviations of absorbance were calculated for each group and statistically analyzed to determine presence or absence of significant difference between the means. The 50% inhibitory dose values were calculated, ranked, and statistically analyzed using the sign interval for median. Based on our results it seems that MTAD is less cytotoxic than eugenol, 3% H2O2, Ca(OH)2 paste, 5.25% NaOCl, Peridex, and EDTA and more cytotoxic than 2.63%, 1.31%, and 0.66% NaOCl.

Topics: Animals; Calcium Hydroxide; Cell Division; Cetrimonium Compounds; Chlorhexidine; Citric Acid; Coloring Agents; Doxycycline; Edetic Acid; L Cells; Mice; Polysorbates; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Tetrazolium Salts; Thiazoles

A total of 100 maxillary molar canals were hand instrumented to a master apical file size #35 and flared to a size #60 file. The canals were randomly divided into 5 groups of 20 each. Group 1 received no further treatment. Groups 2 and 3 received passive sonic irrigation for 30 and 60 s, respectively. Groups 4 and 5 received passive ultrasonic irrigation for 30 and 60 s, respectively. The roots were split longitudinally and photographed with a digital camera. The apical portion of the root was magnified to 100x. A debris score was calculated for the apical 3 and 6 mm. The debris score was calculated as a percentage of the total area of the canal that contained debris as determined by pixels in Adobe Photoshop 5.0. Passive sonic or ultrasonic irrigation, for as little as 30 s, resulted in significantly cleaner canals than hand filing alone. Ultrasonic passive irrigation produced significantly cleaner canals than passive sonic irrigation, when sonic and ultrasonic passive irrigation were compared with only each other.

Topics: Analysis of Variance; Humans; Molar; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Sonication; Statistics, Nonparametric; Therapeutic Irrigation; Ultrasonics

To compare several parameters of root-canal preparation using two different rotary nickel-titanium (NiTi) instruments: Lightspeed (Lightspeed Inc, San Antonio, TX, USA) and Quantec SC (Tycom, Irvine, USA).. Fifty extracted mandibular molars with root-canal curvatures between 20 degrees and 40 degrees were embedded into a muffle system. All root canals were prepared to size 45 followed by a stepback in 1-mm increments to size 70 (Lightspeed) or 45 (Quantec SC), using a high-torque motor at 1300 or 350 r.p.m. respectively. In both groups, irrigation was performed with 2 mL NaOCl (3%) after each instrument size. RC-Prep (Premier, PA, USA) was used as a chelating agent. The following parameters were evaluated: straightening of curved root canals, postoperative root-canal diameter, working safety (instrument fractures, perforations, apical blockages, loss of working length (WL)), cleaning ability and working time. Cleanliness of the root-canal walls was investigated under SEM using 5-score indices for debris and smear layer. Statistical analysis was performed using the Wilcoxon's test (P < 0.05) for straightening and Fisher's exact test (P < 0.05) for comparison of cross-sections, contact between pre- and postoperative diameter, root-canal cleanliness and working time.. Both NiTi systems maintained the curvature well: the mean degree of straightening was 1.8 degrees for Lightspeed and 1.7 degrees for Quantec SC; differences were not significant. Procedural incidents occurred with Quantec SC in 12 root canals (three fractures, four apical blockages and five cases of loss of WL), preparation with Lightspeed resulted in five fractures, one apical blockage and five cases of loss of WL (11 incidents). Following preparation with Lightspeed, 55.5% of the root canals had a round diameter, 25% an oval and 19.5% an irregular diameter; Quantec SC preparations resulted in a round diameter in 51.5%, oval shape in 33.3% and irregular cross-sections in 15.2% of the cases. Mean working time was similar for Quantec SC (161 s) and Lightspeed (155 s); the difference was not significant. For debris, Lightspeed and Quantec achieved 64 and 63% for scores 1 and 2, respectively. For smear layer, Lightspeed and Quantec achieved only 13.3 and 27.4% for scores 1 and 2, respectively. Differences were not significant for either debris or smear layer.. Both systems respected original root-canal curvature well and prepared acceptable diameter forms. The cleaning ability was judged not satisfactory for both systems. Both systems showed deficiencies in working safety.

Topics: Chelating Agents; Dental Alloys; Dental High-Speed Equipment; Dental Pulp Cavity; Disinfectants; Edetic Acid; Equipment Design; Equipment Failure; Equipment Safety; Humans; Microscopy, Electron, Scanning; Nickel; Peroxides; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Time Factors; Titanium; Urea; Waxes

The aim of this study was to evaluate accessory canal obturation after four different final irrigation regimes. Sixty-four extracted human lower premolars were instrumented, divided randomly into four groups, and finally irrigated as follows: no irrigation (NO), distilled water (WA), sodium hypochlorite ([SH] 6%, 20 ml for 15 min), and EDTA (15%, 8 ml for 3 min) combined with the SH regimen (ES). The System B and the Obtura II were used to fill the canals. The teeth were cleared and observed under a digital microscope. Obturation material penetration rates in length into the accessory canals were measured and the following values were obtained: 22.3% in group NO, 21.8% in group WA, 53.5% and 68.1% in groups SH and ES, respectively. Statistically significant differences were found when comparing each of the first two groups (NO and WA) with SH and ES groups (p < 0.05). The use of sodium hypochlorite alone or in combination with EDTA in final irrigation flushes may enhance a better obturation material penetration into the accessory canals.

Topics: Bicuspid; Dental Pulp Cavity; Edetic Acid; Humans; Random Allocation; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Water

The purpose of this study was to evaluate the effects of EDTA on smear layer removal and on the structure of dentin, after 1 and 10 min of application. Six extracted single-rooted teeth were instrumented to #60. Apical and coronal thirds of each root were removed, leaving a 5 mm middle third that was then cut longitudinally into two equal segments. Using 10 ml of 17% EDTA solution, halves belonging to the same root were irrigated for 1 and 10 min, respectively. All specimens were subjected to irrigation with 10 ml of 5% NaOCl. Then all the specimens were prepared for SEM evaluation. The results showed that 1 min EDTA irrigation is effective in removing the smear layer. However a 10-min application of EDTA caused excessive peritubular and intertubular dentinal erosion. Therefore we suggest that this procedure should not be prolonged >1 min during endodontic treatment.

Topics: Anti-Infective Agents, Local; Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Time Factors

The aim of the present study was to assess debris and smear layer remaining following canal preparation with GT rotary instruments.. Sixteen freshly extracted single-rooted premolar teeth were instrumented with GT rotary instruments using a crown-down preparation technique. All specimens were flushed with 2 mL of 5% NaOCl between each rotary instrument. At the end of instrumentation the following final irrigation sequence was repeated two times: 2 mL of EDTA + Cetrimide for 1 min (Largal Ultra, Septodont, France) and 2 mL of 5% NaOCl for 5 min. A final flush with saline solution was made to halt any chemical activity. Two other uninstrumented teeth that were not irrigated served as controls. All teeth were split longitudinally and prepared for SEM evaluation. The presence of debris and smear layer was evaluated from photomicrographs at x200 and x1000 magnification taken in the apical, middle and coronal thirds of the canals. Blind evaluation was performed by two trained observers and scores were compiled separately. A five category scoring system for debris and smear layer was used. Values obtained were tabulated and statistical analysis was carried out using a parametric chi-squared test.. Statistical analysis showed that there was no significant difference between the three regions of the root canals (P > 0.05) for debris. Comparison of the removal of the smear layer between the three regions showed that there was a statistically significant difference between all parts, especially between the coronal and apical thirds (P < 0.001). Overall, the coronal sections were cleaner than the middle and apical sections. The uninstrumented canals showed walls completely covered with tissue, confirming that specimen preparation alone did not remove tissue.. Under the conditions of the present study GT rotary instruments removed debris effectively, but left root canal walls covered with smear layer, particularly in the apical third.

Topics: Bicuspid; Cetrimonium; Cetrimonium Compounds; Chi-Square Distribution; Dental Pulp Cavity; Edetic Acid; Equipment Design; Humans; Microscopy, Electron, Scanning; Observer Variation; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Statistics as Topic

This study aimed to evaluate penetration of propylene glycol into root dentine.. Safranin O in propylene glycol and in distilled water were introduced into root canals with and without artificial smear layer. Dye diffusion through dentinal tubules was determined spectrophotometrically. The time required for dye to exit through the apical foramen using propylene glycol and distilled water as vehicles was also determined. The extent and areas of dye penetration on the split surfaces of roots were assessed using Adobe Photoshop and NIH Image Software.. Propylene glycol allowed dye to exit faster through the apical foramen. The area and depth of dye penetration with propylene glycol was significantly greater than with distilled water (P < 0.0001). Smear layer significantly delayed the penetration of dye.. Propylene glycol delivered dye through the root canal system rapidly and more effectively indicating its potential use in delivering intracanal medicaments.

Topics: Coloring Agents; Dental Pulp Cavity; Dentin; Diffusion; Humans; Image Processing, Computer-Assisted; Matched-Pair Analysis; Pharmaceutical Vehicles; Phenazines; Propylene Glycol; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Spectrophotometry; Statistics as Topic; Time Factors

The aim of this study was to evaluate the effectiveness of oxidative potential water (OPW) as an irrigant, based on its ability to remove the smear layer and/or debris from instrumented root canals.. One hundred and twenty root canals from extracted human maxillary incisors were instrumented using a conventional step-back technique with irrigation from sodium hypochlorite (NaOCl) or oxidative potential water (OPW). After instrumentation, the canals were irrigated by syringe or ultrasound using 15% EDTA or OPW as an irrigant. The volume of each irrigant used for syringe irrigation was 10, 20, and 30 mL, respectively, whilst the duration for ultrasonic irrigation was 1, 3, and 5 min, respectively. After irrigation, each root was split longitudinally in two with cutting pliers, and the specimens were prepared for SEM observation. The presence of debris and smear layer on each canal wall was assessed using a three-point scale for each parameter.. Smear layer was effectively removed with EDTA both introduced via syringe and via ultrasonic irrigation. A similar effect was observed with OPW via syringe irrigation following instrumentation with 5% NaOCl. The canal walls in any of these cases showed open and patent dentinal tubules following smear layer removal. Some specimens irrigated with EDTA exhibited the effect of demineralization on the dentine resulting in funnelling of tubule orifices. Syringe irrigation was more effective in smear layer removal, except for ultrasonic irrigation with 15% EDTA, whilst ultrasonic irrigation was more effective in debris removal including the use of OPW as irrigant following instrumentation with 5% NaOCl. Neither syringe nor ultrasonic irrigation with OPW following instrumentation with OPW removed smear layer or debris effectively.. The most effective irrigation technique for smear removal was 15% EDTA irrigation by means of syringe following instrumentation with 5% NaOCl solution. However, the most effective irrigation technique for debris removal was ultrasonic irrigation regardless of irrigant used. OPW irrigation by means of syringe following instrumentation with 5% NaOCl showed a similar effect to that of 15% EDTA irrigation for removal of smear layer and debris.

Topics: Anti-Infective Agents, Local; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Incisor; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Syringes; Therapeutic Irrigation; Ultrasonic Therapy; Water

The purpose of this scanning electron microscope (SEM) study was to compare the cleanliness of the root canal walls following either a manual or a rotary technique of canal instrumentation. The hypothesis was that a rotary technique would produce a cleaner root canal.. Manual filing was performed on 10 extracted teeth using stainless steel S-files (Sjodings, Sendoline, Sweden). Powered instrumentation was carried out on a further 10 extracted teeth, using ProFile rotary nickel-titanium files in a handpiece (250 r.p.m.) according to the manufacturer's instructions. A solution of 0.5% sodium hypochlorite was used for irrigation. The roots were cut longitudinally and the canal walls were examined for debris and smear layer at the apical, middle and coronal level.. Significantly less debris was found in the apical region using the manual filing technique (P < 0.05); no significant differences could be found at the other levels. Overall, significantly less debris was found on the root canal walls using the manual technique when the data from the three levels were compared (P = < 0.05).. The manual technique employed in this study produced cleaner root canal walls than the rotary ProFile technique.

Topics: Anti-Infective Agents, Local; Dental Alloys; Dental Pulp Cavity; Equipment Design; Humans; Microscopy, Electron, Scanning; Nickel; Reproducibility of Results; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Stainless Steel; Statistics, Nonparametric; Titanium; Tooth Apex

The purpose of this study was to compare several parameters of root canal preparation using two different rotary nickel-titanium instruments: HERO 642 (Micro-Mega, Besancon, France) and Quantec SC (Tycom, Irvine, CA, USA).. Fifty extracted mandibular molars with root canal curvatures between 20 micro and 40 micro were imbedded into a muffle system. All root canals were prepared to size 45 (Quantec SC), or 40 (HERO 642), respectively. The following parameters were evaluated: straightening of curved root canals, postoperative root canal diameter, safety issues (file fractures, perforations, apical blockages, loss of working length), cleaning ability, and working time.. Both Ni-Ti-systems maintained curvature well; the mean degree of straightening was 2.3 degrees for Quantec SC and 1.6 degrees for HERO 642. Most procedural incidents occurred with Quantec SC instruments (five fractures, three apical blockages, eight cases of loss of working length), HERO 642 preparation resulted in three blockages and one perforation. Following preparation with HERO 642, 63% of the root canals showed a round, 24% an oval, and 17% an irregular diameter; Quantec SC preparations resulted in a round diameter in 24% of the cases, oval shape in 29%, and irregular cross-section in 47% of the cases. Mean working time was shorter for HERO 642 (52 s) than for Quantec (117 s). Cleanliness of the root canal walls was investigated under the SEM using a five-score system for debris and smear layer. For debris HERO 642 achieved better results (80% scores 1 and 2) than Quantec SC (76%). The results for smear layer were similar: cleaner root canal walls were found after preparation with HERO 642 (53% scores 1 and 2), followed by Quantec SC (41%).. Both systems respected original root canal curvature well and showed good cleaning ability; Quantec SC showed deficiencies in terms of safety.

Topics: Anti-Infective Agents, Local; Dental Alloys; Dental Pulp Cavity; Dentin; Equipment Design; Equipment Failure; Equipment Safety; Humans; Microscopy, Electron, Scanning; Molar; Nickel; Root Canal Irrigants; Root Canal Preparation; Rotation; Safety; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Statistics, Nonparametric; Time Factors; Titanium; Tooth Apex

The effect of tetracycline hydrochloride as an endodontic irrigant on smear layer removal was examined by scanning electron microscopy and compared with bidistilled water, 2.5% sodium hypochlorite (NaOCl), and 50% citric acid in 20 extracted teeth. Five teeth, as a control, were irrigated with bidistilled water only in group 1. All the other groups were irrigated with NaOCI during instrumentation. The final rinses were NaOCl in group 2, citric acid in group 3, and 1% tetracycline hydrochloride in group 4. Scanning electron microscopic results and statistical analysis revealed that bidistilled water and NaOCl were ineffective in removing the smear layer, whereas citric acid and tetracycline hydrochloride were significantly more effective (p < 0.001). No statistically significant difference was detected between tetracycline hydrochloride and citric acid (p > 0.05). However tetracycline hydrochloride demineralized less peritubular dentin.

Topics: Anti-Bacterial Agents; Citric Acid; Cuspid; Dentin Permeability; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties; Tetracycline

This study compared the smear layer removing capability and cytotoxicity of NaOCl, EDTA and Oxidative Potential Water (OPW). Fifteen extracted single-rooted human upper incisors were examined in three groups. The root canals were enlarged to the apical foramen with K files to size #60 and irrigated with: (a) NaOCl followed by OPW, (b) OPW during and after instrumentation and (c) NaOCl followed by EDTA and NaOCl. The effect of these irrigants on the smear layer was evaluated using a scanning electron microscope. In vitro cytotoxicity of these irrigants was examined by MTT colorimetric assay. We found that the combination of NaOCl and OPW as well as the application of OPW alone, failed to remove the smear layer from the apical third, whereas the EDTA and NaOCl combination achieved complete removal. OPW, when used during and after instrumentation, removed the smear layer in the middle third more effectively than NaOCl followed by OPW. EDTA exerted more cytotoxic effects at all concentrations tested when compared with OPW and NaOCl.. (a) OPW was less cytotoxic than other irrigants but did not effectively remove the smear layer, (b) treatment with EDTA followed by NaOCl efficiently removed of the smear layer, but their cytotoxicity should be considered during endodontic therapy.

Topics: Animals; Anti-Infective Agents, Local; Cell Division; Cell Survival; Cells, Cultured; Chelating Agents; Colorimetry; Coloring Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Fibroblasts; Humans; Incisor; Linear Models; Mice; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tetrazolium Salts; Thiazoles; Water

Debris and smear layer were evaluated in canals prepared with either Lightspeed (LS) or ProFile (PF) rotary instruments. Irrigants used were tap water (group A) or alternating 5.25% NaOCl and 17% EDTA (group B). Apical stops were prepared to size 52.5 in the LS and to size 6 (approximately ISO size 36) in the PF techniques. The roots were split longitudinally and examined at apical, middle and coronal levels for debris and the smear layer using a 5-step scale. Using only water, mean debris scores were similar for LS and PF. In contrast, with EDTA/NaOCl, LS- and PF-prepared canals had similar debris scores at the apical and coronal levels, but there was a significant difference at the middle level. Mean smear layer scores were similar in LS- and PF-shaped canals when water was the sole irrigant. In contrast, with NaOCl and EDTA, mean smear layer scores were significantly different at the apical and middle levels, but not at the coronal level. Neither technique was superior in removing debris, but larger canal preparations obtained in this study with LS instruments enabled a more effective removal of the smear layer in the EDTA-NaOCl group.

Topics: Dental High-Speed Equipment; Dental High-Speed Technique; Dental Pulp Cavity; Edetic Acid; Humans; Molar; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Titanium

The purpose of this in vitro study was to determine the degree of removal of pulpal remnants and smear layer from root canals after final irrigation with three different solutions. During instrumentation the step-back preparation and 1% NaOCl were used. The final 4-min, 30-ml irrigation varied as follows: group I, 10 ml of 1% NaOCl + 10 ml of 10% citric acid + 10 ml of distilled water; group II, 15 ml of 0.5% NaOCl + 15 ml of EDTA-T; and group III, 10 ml of 5% NaOCl + 10 ml of 3% H2O2 + 10 ml of 5% NaOCl. Scanning electron microscopic photomicrographs were evaluated for the mean number of visible open dentinal tubules by three observers. The largest number of visible tubules in the three groups was in the cervical third, followed by the middle and apical thirds. There was no statistically significant difference between groups I and II when third was compared with third; however, groups I and II had significantly more visible dentinal tubules than group III.

Topics: Acid Etching, Dental; Analysis of Variance; Chelating Agents; Citric Acid; Dental Pulp; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Observer Variation; Oxidants; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex; Tooth Cervix

The purpose of this study was the in vitro evaluation of four techniques for the obturation of the root canal system in the presence or absence of a smear layer. Ninety-six human upper central incisors were instrumented using the pressureless crown-down technique and irrigated with 5.25% NaOCl. The teeth that had the smear layer removed were irrigated with this solution in combination with 17% EDTA. The teeth were obturated with lateral condensation with an accessory or standardized cone as the main cone, with vertical condensation of warm gutta-percha or with thermoplasticized injectable gutta-percha. Apical leakage was assessed by measuring the linear penetration of methylene blue dye with a stereomicroscope. The results showed no significant differences in the degree of leakage with and without the smear layer when the samples were considered as a whole. However, when the groups were assessed separately, teeth in the lateral condensation with an accessory main cone group and teeth in the thermoplasticized group leaked less with a smear layer present. In contrast teeth with lateral condensation and a standardized main cone leaked more with a smear layer present. In the vertical condensation groups there was no difference attributable to the smear layer.

Topics: Chelating Agents; Coloring Agents; Dental Bonding; Dental Leakage; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Gutta-Percha; Humans; Incisor; Methylene Blue; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite; Statistics as Topic

A new product, electro-chemically activated water, was compared to NaOCl for its cleaning effect on root canal walls.. Root canal treatment was carried out on two groups of extracted teeth with one of the irrigants being used in each group. The control group received no treatment. All teeth were split and the canal walls viewed in a scanning electron microscope.. The canal walls of the control group were covered by debris and bacteria. Sodium hypochlorite produced clean surfaces with the dentinal tubules open in some areas and occluded by the smear layer in other areas; in some areas bacteria were visible inside or under the smear layer. Electro-chemically activated water produced markedly cleaner surfaces, removing the smear layer in large areas.. The cleaning efficacy of electro-chemically activated water in root canals was considered to be superior to NaOCl.

Topics: Bacteria; Dental Pulp Cavity; Dentin; Electrochemistry; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy; Water

The purpose of this study was to evaluate the effects of smear layer and canal instrumentation on leakage in root-filled teeth.. Six groups (n = 12) of freshly extracted human canines and premolars with closed apices and single roots were used. Groups A, B, C, and D were instrumented with engine-driven rotary nickel-titanium MCXIM files and Groups E and F were instrumented with conventional stainless steel hand files. Groups A, C, and E were flushed with 3.0 mL of 17.0% REDTA to remove the smear layer prior to obturation. All teeth were flushed with 5.25% NaOCl, then obturated with AH-26 sealer and either the lateral condensation (Groups C-E) or thermomechanical compaction technique (Groups A and B). Copper wire was placed coronally in contact with the gutta-percha in each tooth and, after immersion in 0.9% NaCl solution, a 10 volt dc voltage was connected between each tooth and a stainless steel electrode. The current flow in the circuit was observed for 45 days. One way ANOVA and Duncan's Multiple Range Test were used to compare Groups A-F at time intervals of 10, 20, 30 and 45 days and identify statistically significant differences.. Significantly less microleakage occurred when the smear layer was removed and when the canals were obturated with thermoplasticized gutta-percha. Canals instrumented with engine-driven NiTi files exhibited less leakage than hand-instrumented canals irrespective of obturation method.. Smear layer removal is beneficial to root canal sealing. Obturation with thermoplasticized gutta-percha provides a superior seal whilst canal instrumentation with engine-driven NiTi files reduces the extent of microleakage in root canals.

Topics: Analysis of Variance; Bicuspid; Bismuth; Cetrimonium Compounds; Chelating Agents; Cuspid; Dental Alloys; Dental Leakage; Disinfectants; Drug Combinations; Edetic Acid; Electrochemistry; Epoxy Resins; Equipment Design; Gutta-Percha; Humans; Methenamine; Nickel; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy; Silver; Smear Layer; Sodium Hypochlorite; Stainless Steel; Statistics as Topic; Titanium

The aim of this study was to develop a test model to quantify the penetration of bacteria into dentinal tubules.. The model consisted of two compartments separated by a bovine dentine specimen with a thickness of 1.5-3.1 mm. The root cementum was removed from the root surface and the specimens were oriented in the model with the pulpal side facing the inoculated chamber of the test model. One compartment contained the test organism and the other was filled with sterile broth that was evaluated for growth of the test organism. The depth of bacterial penetration was measured in the dentine with or without a smear layer using both a histological and a quantitative recovering grinding technique, after 6 weeks of exposure to the microorganisms.. E. faecalis penetrated dentine significantly deeper than A. israelii (P < 0.001). After removal of the smear layer with EDTA, E. faecalis penetrated significantly deeper than in dentine pretreated with saline only (P < 0.01) or with a combination of saline and sodium hypochlorite (P < 0.01). Microorganisms were found in 89% of the cultured specimens and in 80% of the specimens that were evaluated with light microscopy. Total penetration through the dentine specimen and infection of the broth in the test compartment of the model occurred in only two out of 72 specimens.. Collection and immediate culturing of infected dentine dust and counting colony forming units (CFU) allowed an overview of the number of bacteria per sample and was more sensitive than microscopy. Removal of the smear layer enhanced bacterial penetration.

Topics: Actinomyces; Analysis of Variance; Animals; Cattle; Chelating Agents; Colony Count, Microbial; Culture Media; Dentin; Disinfectants; Edetic Acid; Enterococcus faecalis; Models, Animal; Sensitivity and Specificity; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Statistics, Nonparametric; Tooth Root

The aim of this study was to evaluate in vitro the cleansing and smear layer removal capability of alternate canal irrigation with citric acid and NaOCl.. Eighty-one teeth were divided into three groups on the basis of the type of instrumentation, namely, manual stainless steel, Ni-Ti mechanized ProFile .04 taper or MACXim. The groups were further divided on the basis of irrigation protocol: 5% NaOCl alone, NaOCl alternated with 1 mol L-1 citric acid solution or a combination of 15% EDTA and Cetrimide solution. After longitudinal sectioning, dentinal walls were microphotographed with scanning electron microscopy at x300 and x1000 magnifications. Qualitative and quantitative cleansing level evaluations were performed using computerized image analysis software. Data were statistically evaluated using Kruskal-Wallis analysis and t-test.. Qualitative evaluation at x300 and x1000 showed no statistically significant differences in cleansing ability between citric acid, EDTA and NaOCl groups. Quantitative evaluation of smear layer removal, measured as open tubules/total dentinal surface ratio, showed that 1 mol L-1 citric acid solution was comparable to EDTA (11.97% vs. 10.36%) (NS); in samples treated with ProFile .04 taper instruments citric acid was most effective (16.17%), whilst in the group treated with manual instrumentation EDTA and Cetrimide were the most effective (11.94%). Specimens irrigated with 5% NaOCl demonstrated significantly more cleansing than those obtained in the other two groups (P < 0.001).. 1 mol L-1 citric acid solution was as effective in removing smear layer as EDTA, but was superior in specimens treated with ProFile .04 taper instruments.

Topics: Cetrimonium; Cetrimonium Compounds; Chelating Agents; Citric Acid; Dental Alloys; Dentin; Detergents; Disinfectants; Edetic Acid; Equipment Design; Humans; Image Processing, Computer-Assisted; Microscopy, Electron, Scanning; Nickel; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Stainless Steel; Statistics as Topic; Statistics, Nonparametric; Titanium

The aim of this study was to evaluate and compare the radiographic quality and sealability of root fillings in extracted human teeth using lateral condensation of gutta-percha or low-temperature thermoplasticized gutta-percha (Ultrafil). One hundred freshly extracted human, mature single-rooted teeth were divided into four identical groups of 25 teeth on the basis of root canal shape. The root canals of two groups were prepared in such a way to produce a relatively parallel shape with little or no flare toward the coronal orifice. The root canals of the other two groups were prepared in such a way as to produce a canal shape that was deliberately more flared to ensure that they were wider at the orifice than at the end point of the preparation. All root canals were flushed with 17% EDTA solution and 2.5% NaOCl to remove the dentinal smear layer. The canals of one flared group and one parallel group were obturated using cold lateral condensation, and the canals of the other two groups were obturated using low-temperature thermoplasticized gutta-percha. The sealability of each technique was assessed by a dye penetration method. The radiographic quality of obturation was determined for each canal using a 4-point scale. Canals filled with thermoplasticized gutta-percha had significantly less apical dye penetration than those obturated by lateral condensation (p < 0.001). Lateral condensation achieved significantly better scores for radiographic quality than thermoplasticized gutta-percha from both the buccolingual (p < 0.005) and mesiodistal views (p < 0.001). Low-temperature thermoplasticized gutta-percha root fillings were associated with significantly more apical extrusion of sealer (p < 0.001) and gutta-percha (p < 0.005). Under laboratory conditions the low-temperature thermoplasticized gutta-percha had better sealability but poorer radiographic quality than lateral condensation.

Topics: Chelating Agents; Cold Temperature; Coloring Agents; Dental Bonding; Dental Leakage; Dental Pulp Cavity; Edetic Acid; Gutta-Percha; Humans; Materials Testing; Oxidants; Radiographic Image Enhancement; Reproducibility of Results; Root Canal Filling Materials; Root Canal Obturation; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Statistics as Topic; Surface Properties

This study used scanning electron microscopy to compare the effectiveness of two new canal lubricants in conjunction with sodium hypochlorite irrigation in removing smear layer. Both lubricants completely removed the smear layer in the coronal and middle thirds of the root canals, but only partially removed the smear layer in the apical thirds. An explanation of the findings is presented and the clinical significance of smear layer is discussed.

Topics: Chelating Agents; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Lubrication; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

The topography of instrumented and uninstrumented canal walls exposed to calcium hydroxide and four different irrigation regimens was observed by scanning electron microscopy. After chemomechanical debridement, one tooth in each matched pair was medicated with calcium hydroxide. One week later, the teeth were irrigated and split longitudinally for evaluation. When no calcium hydroxide was used, predentin and pulpal debris covered the dentinal tubules of the uninstrumented surfaces in specimens irrigated with water or EDTA, but was absent on uninstrumented surfaces in specimens irrigated with NaOCl or NaOCl and EDTA. A typical smear layer was absent in instrumented specimens irrigated with NaOCl and EDTA, but covered the dentinal tubules of the instrumented surfaces of the EDTA irrigated specimens (partially) and the water or NaOCl irrigated specimens (completely). Calcospherites or their remnants were seen on the uninstrumented canal walls of specimens irrigated with NaOCl or NaOCl and EDTA, respectively. Calcium hydroxide use did not alter the surface topography in specimens irrigated with water, EDTA, or NaOCl, but seemed to erode the intertubular dentin in specimens irrigated with NaOCl and EDTA. All irrigants seemed to effectively remove most of the calcium hydroxide.

Topics: Calcium Hydroxide; Dental Pulp Cavity; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

The purpose of this study was to examine the effect of the smear layer on apical microleakage over 16 wk. One hundred and four extracted human teeth were assigned to four groups treated as follows: group A1--smear layer was left intact and canals were obturated with gutta-percha and Roth 811; group A2--smear layer was left intact and canals were obturated with gutta-percha and AH26; group B1--smear layer was removed and canals were obturated with gutta-percha and Roth 811; and group B2--smear layer was removed and canals were obturated with gutta-percha and AH26. Microleakage was measured by the electrochemical method. In parallel, 12 teeth were examined under a scanning electron microscope. The results indicated that the smear layer removal resulted in a statistically significant reduction of microleakage values in groups obturated with AH26. The presence or absence of smear layer had no significant effect on the sealing ability of Roth 811.

Topics: Bismuth; Dental Leakage; Drug Combinations; Edetic Acid; Epoxy Resins; Evaluation Studies as Topic; Gutta-Percha; Humans; Methenamine; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Silver; Smear Layer; Sodium Hypochlorite; Titanium; Zinc Oxide-Eugenol Cement

The purpose of the present scanning electron microscopic study was to investigate the efficacy of a combination of EDTA, NaOCl, and surface-active irrigating solutions during and after root canal preparation with ProFile nickel-titanium rotary instruments. Thirty canals were divided into three groups, instrumented and irrigated as follows: 5% NaOCl and a final flush with 17% EDTA were used for group A; group B specimens were irrigated using 17% EDTA, followed 15 s later by 1% TRITON X-100 (tensioactive agent) and then by 5% NaOCl; and group C specimens were irrigated with the same combination, but once shaping procedures were completed the irrigating sequence was repeated three times. After scanning electron microscopic evaluation, group C specimens exhibited the most effective debridement of the root canals. Results showed that tensioactive agent contributed to enhanced debridement. Cleaning was significantly improved once shaping procedures were completed.

Topics: Chi-Square Distribution; Dental High-Speed Technique; Dental Instruments; Dentin; Edetic Acid; Humans; Microscopy, Electron, Scanning; Nickel; Octoxynol; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Titanium

The aim of this study was to evaluate the effects of NaOCl at removing the demineralized layer by examining the morphology of the hybrid layer and measuring shear bond strengths after different dentin treatments.. Dentin disks were treated with: (1) 35% phosphoric acid (PA) 20 s; (2) PA treatment followed by 1.5% NaOCl, 2 min; (3) PA treatment, followed by a 10% NaOCl immersion for 120 h. SEM was used to analyze the morphology of dentin and its interface with dentin bonding agents (DBAs), while shear bond strength tests were used to measure adhesion. All specimens were then fractured into two halves: One half was inspected under SEM; the other half was sequentially placed in 10% PA followed by 12.5% NaOCl for 70 h, to remove all dentin from the resin replica of the original bonded interface.. SEM observations showed that collagen fibrils were completely removed from the acid-etched surface by NaOCl treatment. The diameter and the size of dentinal tubules and the number of lateral branches of the tubules were increased following NaOCl treatment. NaOCl applied on dentin smear layers did not significantly modify their SEM morphology. Resin tags were larger in diameter after phosphoric acid/NaOCl treatment than after only phosphoric acid treatment. Resin-infiltrated dentin-layers were only observed after the single phosphoric acid (i.e. conventional etching) procedure, and were not observed after combined phosphoric acid/NaOCl treatment. Etched/NaOCl samples showed a lower bond strength using Scotchbond MP and 3M Single Bond, but were higher in Optibond FL and unmodified in Prime & Bond 2.0 groups when compared with acid-etched controls. Treatment of etched dentin with NaOCl for 120 h produced an unusual type of resin infiltration of mineralized dentin that could be called a "reverse hybrid layer" which may explain the mechanism of resin bonding to NaOCl treated dentin.. The use of acidic conditioners for exposure of the collagen matrix exposes a soft delicate mesh that can collapse, thereby interfering with resin infiltration. If acid-etching is followed by NaOCl treatment, high bond strengths can be achieved via "reverse hybrid layer" formation, a proposed new mechanism of micromechanical resin retention. This mechanism is not yet recommended for clinical use but demonstrates a new type of resin retention.

Topics: Adolescent; Adult; Analysis of Variance; Bisphenol A-Glycidyl Methacrylate; Collagen; Composite Resins; Dental Bonding; Dentin; Dentin Permeability; Dentin-Bonding Agents; Humans; Materials Testing; Microscopy, Electron, Scanning; Polymethacrylic Acids; Resin Cements; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties; Tensile Strength

The effect of two different root canal cements and removal of the smear layer on the apical seal in roots obturated with Thermafil obturators was tested. Thirty extracted human mandibular first molars with 60 canals (mesial roots) were instrumented with the use of a step-back technique. Teeth were placed into 6 groups of 10 canals each. The first three groups had the smear layer removed with EDTA and NaOCl, and the other three groups were irrigated with NaOCl only. Canals were obturated using Thermafil without sealer cement or Thermafil with Ketac-Endo or Thermafil with zinc oxide-eugenol cement. All roots were placed in India ink for 4 days. The roots were cleared, and the degree of linear dye penetration was measured. The study showed that root canal cement significantly improved the apical seal of the Thermafil obturation technique (p < 0.05), whether the smear layer was removed or not. The apical seal exhibited by Ketac-Endo was not significantly different from that provided by zinc oxide-eugenol cement (p > 0.05), regardless of the presence or absence of a smear layer.

Topics: Analysis of Variance; Dental Leakage; Edetic Acid; Glass Ionomer Cements; Gutta-Percha; Humans; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite; Zinc Oxide-Eugenol Cement

The aim of the present study was to evaluate the effect of 4% titanium tetrafluoride (TiF4) solution on root canal walls by scanning electron microscopy. Twenty four root canals with or without a smear layer were treated with 4% TiF4 solution. Scanning electron microscopic observation of the smeared canal walls showed that TiF4 solution modified the smear layer and produced a massive structure. In smear-free group, a granular coating was formed on intertubular and intratubular dentin. The stability of this layer was tested further with EDTA and/or NaOCl irrigations on 20 additional specimens. It was observed that none of the solutions was able to remove this modified smear layer. These results may indicate that this extremely stable structure may be advantageous in endodontics, because it can prevent further infection of root canal dentin by sealing off the tubules permanently, and can reduce microleakage by preventing further dissolution and disintegration of the smear layer.

Topics: Cariostatic Agents; Dental Leakage; Dental Pulp Cavity; Dentin; Edetic Acid; Evaluation Studies as Topic; Fluorides; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Titanium; Tooth Root

Blocks of bovine incisor dentin, on the root canal surface of which a smear layer had been formed, were inoculated in vitro with two strains of Prevotella nigrescens, a wild sampled strain and a reference one (NCTC 9336). Half the blocks were pretreated with irrigating solutions: 6% citric acid for 5 min + 6.25% sodium hypochlorite for 10 min. They were compared with the other blocks simply rinsed in distilled water (i.e. the control samples). The bacteria adhering to the dentin surface after an incubation time of 3 h were counted by direct examination using a scanning electron microscope. The adhesion of P. nigrescens was less marked on all of the samples treated with irrigating solutions. Adherence was particularly significant in the case of the wild strain (F = 10.22). The latter was far more active than the reference strain (F = 35.82). The use of a chelating agent at the end of root canal preparation served to remove the smear layer and limited the attachment of P. nigrescens to the dentin.

Topics: Animals; Bacterial Adhesion; Cattle; Citric Acid; Dental Pulp Cavity; Dentin; Microscopy, Electron, Scanning; Prevotella; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

The purpose of this study was to examine the effect of the smear layer on the penetration depth of Sealapex, Roth 811, and CRCS root canal sealers into the dentinal tubules. Forty recently extracted, human single-rooted teeth were used. The crowns were cut and removed at the cemento-enamel junction level and the root canals were prepared to a #60 K-file. The teeth were then randomly divided into two groups of 20, group A and group B. The smear layer was removed from all teeth in group A with EDTA and NaOCl. The smear layer remained in all teeth in group B. Two roots in each group were used as controls. Six roots from each group were obturated with Roth 811 sealer and gutta-percha through lateral condensation. The same process was repeated using sealers CRCS and Sealapex. Each root was then divided in two and prepared for scanning electron microscope observation. The removal of the smear layer allowed penetration of all three sealers into the dentinal tubules to a depth of between 35 microns and 80 microns. Although the CRCS sealer penetrated only up to the 35 mm point, it offered better or complete obturation of the dentinal tubules. The presence of smear layer at the root canal walls obstructed the penetration of all sealers into the dentinal tubules.

Topics: Adult; Analysis of Variance; Calcium Hydroxide; Dentin; Dentin Permeability; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Salicylates; Smear Layer; Sodium Hypochlorite; Zinc Oxide; Zinc Oxide-Eugenol Cement

The study aimed to evaluate intracanal irrigation procedures in eradicating bacteria from surface, shallow and deep layers of root dentine using extracted human teeth. Artificial bacterial smear layer was successfully produced by rubbing a mixture of dental plaque and artificially decalcified dentine or carious dentine on root canal walls. The reservoir holes were 3.5 mm in depth, 1 mm in diameter prepared 1.5 mm apart and parallel to the root canals on the decrowned planes, in which five separate bacterial species were placed (Actinomyces israelii, Fusobacterium nucleatum, Propionibacterium acnes, Streptococcus mutans and Streptococcus sanguis). Bacterial eradication after irrigation of the prepared canals was determined by bacterial recovery (i) from the root canal surfaces and shallow layers where bacteria were smeared artificially and (ii) from deeper layers of root canal dentine reservoir holes. Ultrasonic irrigation with 5.5% and 12% NaOCl eradicated bacteria from artificial smear layer (P < 0.0001), whilst 12% NaOCl irrigation with a syringe was insufficient. Ultrasonic irrigation with water or 15% EDTA-failed to eradicate bacteria from smeared surfaces. Ultrasonic irrigation with 12% NaOCl killed A. israelii, F. nucleatum, P. acnes, S. mutans, and S. sanguis placed in reservoir channels, although for F. nucleatum, a very small number of bacteria remained in five samples out of 12. Ultrasonic irrigation with less concentrated NaOCl failed to eliminate bacteria completely from reservoir channels in most samples. Ultrasonic irrigation with 12% NaOCl appeared to eliminate bacteria efficiently from surface, shallow and deep layers of root dentine.

Topics: Actinomyces; Bacteria; Colony Count, Microbial; Dental Pulp Cavity; Dentin; Dose-Response Relationship, Drug; Edetic Acid; Fusobacterium nucleatum; Humans; Microscopy, Electron, Scanning; Propionibacterium; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Streptococcus; Tooth Root; Ultrasonics

To investigate the effect on shear bond strength of the presence or absence of the demineralized collagen layer on both wet and dried etched dentin surfaces.. Composite cylinders were mounted on dentin surfaces after the following treatments; 37% etch/wet, 37% etch/dry, 37% etch/NaOCl/wet, 37% etch/NaOCl/dry, No-etch/wet, No-etch/dry, No-etch/NaOCl/wet, No-etch/NaOCl/dry. 24-hr shear bond strength data was obtained. SEM examinations of various surfaces were also conducted.. Wet bonded specimens had significantly higher shear bond strengths, with or without the presence of the demineralized collagen layer, whether they were acid-treated or not. Acid-etched specimens had significantly higher shear bond strengths than unetched specimens.

Topics: Acid Etching, Dental; Adhesiveness; Analysis of Variance; Collagen; Dental Bonding; Dentin; Dentin-Bonding Agents; Humans; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Phosphoric Acids; Resin Cements; Smear Layer; Sodium Hypochlorite; Surface Properties; Wettability

Cleansing and shaping result in a smear layer on the instrumented canal wall surfaces. The smear layer may inhibit close contact between sealers and dentin, and inhibits diffusion of medicaments.. This study assessed the effect of doxycycline hydrochloride (DH) on smear layer on intracanal walls.. Scanning electron microscopy was used to evaluate the remaining smear layer using different concentrations of DH. Single-canal palatal roots of extracted maxillary molars were irrigated with saline-15% EDTA; saline-25 mg/ml DH; saline-50 mg/ml DH; saline-100 mg/ml DH; NaOCl-15% EDTA; NaOCl-25 mg/ml DH; NaOCl-50 mg/ml DH; and NaOCl-100 mg/ml DH. The roots were fractured into halves and the amount of smear layer assessed in the middle and apical third.. Doxycycline-HCl of 100 mg/ml was the most effective in removing smear layer. In the saline group, 100 mg/ml of DH was more effective than EDTA. In the hypochlorite group, 50 mg/ml and 100 mg/ml of DH were more effective than EDTA (p < 0.05).. Doxycycline solution may be an effective irrigant.

Topics: Anti-Bacterial Agents; Chi-Square Distribution; Dental Pulp Cavity; Dentin; Doxycycline; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Single-Blind Method; Smear Layer; Sodium Chloride; Sodium Hypochlorite

In this in vitro study, we investigated the efficacy of sodium hypochlorite (NaOCl) and calcium hydroxide (Ca(OH)2) in dissolving necrotic tissue and cleaning root canals. In the first part of the study, 0.5% NaOCl solution and Ca(OH)2 paste and solution were tested with samples of necrotic bovine muscle in different treatment modes and for different periods. The necrotic tissue was weighed before and after the test and the percentage of weight change calculated. In the second part of the study, 40 extracted single-rooted human teeth were hand instrumented and then subjected to different irrigation regimens. The cleansing efficacy in root canals of 0.5% NaOCl with Ca(OH)2 pretreatments and ultrasonics was examined using scanning electron microscopy. A solution of 5% NaOCl was significantly more effective than 0.5% NaOCl as a solvent of necrotic tissue. Calcium hydroxide was an effective solvent for necrotic tissue as a paste but not as a solution. Pretreatment of necrotic tissue with Ca(OH)2 increased its solubility in 0.5% NaOCl. While 5% NaOCl plus ultrasonic irrigation produced cleaner root-canal walls at the middle and apical thirds, 0.5% NaOCl used with the same technique achieved no root-canal cleaning. However, pretreatment of root canals with Ca(OH)2 paste increased the effectiveness of 0.5% NaOCl plus ultrasonic irrigation, except in the coronal third of the root canal.

Topics: Animals; Calcium Hydroxide; Cattle; Dental Disinfectants; Dental Pulp Cavity; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Muscles; Necrosis; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonic Therapy

The purpose of this study was to examine the effect of smear layer on coronal microleakage. Fifty-two single-rooted extracted human teeth with a straight root canal were chemomechanically prepared and equally divided into experimental groups A and B. The teeth in group B were treated with ethylenediamine tetraacetic acid and sodium hypochlorite to remove the smear layer. All teeth in the experimental groups were next obturated with gutta-percha and sealer. Finally they were tested for dye leakage with methylene blue. Linear and volumetric measurement of dye penetration was used to assess leakage. The results of this study suggest that the removal of smear layer significantly improves the tightness of the sealing in the coronal area.

Topics: Coloring Agents; Dental Leakage; Dental Pulp Cavity; Edetic Acid; Humans; Methylene Blue; Microscopy, Electron, Scanning; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Crown

In light of the in vitro S. sanguis bacterial migration observed deep into root dentin, an in vitro system was developed to determine the viability of these bacteria at the end of migration. Also of interest is whether the smear layer formed during root canal instrumentation modifies migration into root dentinal tubules. Forty-eight bovine root dentin samples were randomly split into two groups. Group 1 dentin blocks were not instrumented and were treated with 17% ethylenediamine tetraacetic acid and 2.5% sodium hypochlorite for 4 minutes in an ultrasonic bath Group 2 root canals were conventionally instrumented. The smear layer formed was not removed. Dentin blocks were inoculated with a S. sanguis National Collection of Type Culture 7863 suspension. Each sample was immersed in a receiver broth, incubated at 37 degrees C, and checked daily for 14 days. After a 14-day incubation period, group 1 S. sanguis cells remained viable and capable of inoculating the receiver medium after migration through the tubules. Group 2 cells, where the smear layer was intact, revealed an absence of S. sanguis migration in 88% of the cases. It is therefore plausible that smear layer on canal walls limits S. sanguis penetration of dentinal tubules in vitro.

Topics: Animals; Cattle; Dental Leakage; Dentin; Dentin Permeability; Edetic Acid; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Streptococcus oralis; Tooth Root

Endodontic preparations may induce changes in the permeability of radicular dentin. The aim of this study was to analyze the variation of hydraulic conductance measured in situ after three endodontic preparations (manual K+H files, ultrasonic preparation, and manual with NaOCI and EDTA). Scanning electron microscopic analysis of the canal walls was made to permit correlations between variations of permeability and the amount of surface covered with smear layer or organic debris. There was an inverse relationship between the variations in dentin permeability and the presence of smear layer. The significance of this correlation was variable according to the techniques used. Dentin thickness was as significant a factor in influencing radicular permeability as was the smear layer. The use of EDTA induced a considerable increase in radicular permeability. The use of ultrasonics produced a similar but weaker effect.

Topics: Analysis of Variance; Chelating Agents; Dental Pulp Cavity; Dentin Permeability; Dentinal Fluid; Edetic Acid; Humans; Hydrostatic Pressure; Linear Models; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties; Ultrasonic Therapy

The effect of raising the temperature of the irrigant solution on the smear layer was evaluated in the middle and apical third of 22 human upper incisors. A 5% sodium hypochlorite (NaOCl) solution was used at 21 degrees C and at 50 degrees C. After hand instrumentation and treatment with the irrigant, teeth were fractured into halves and examined by scanning electron microscopy. Characteristics of the smear layer in the two groups of specimens were compared. In the middle third, where NaOCl had been used at 50 degrees C, the smear layer was thinner and made of finer, less well-organized particles than where it had been used at 21 degrees C. In the apical third, the smear layer was of almost the same thickness in the two groups of specimens, although the particles were finer where the NaOCl had been used at 50 degrees C.

Topics: Dental Pulp Cavity; Hot Temperature; Humans; Incisor; Maxilla; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite

Scanning electron microscopy was used to analyze the smear layer removal after root canal preparation by a manual technique and by an automated handpiece, the Canal Finder System (CFS). When 1% sodium hypochlorite was used as the irrigating solution, both manual and CFS techniques showed root canal walls with a dense smear layer obscuring the dentinal tubules entrance plus a large amount of debris. Root canal walls of the group of teeth treated with a chelating agent (EDTA) for 5 min and a final flush, after the preparation, with 1% sodium hypochlorite as an irrigating solution showed the cervical, middle and apical thirds extremely smooth and clear.

Topics: Dental High-Speed Equipment; Dental Pulp Cavity; Edetic Acid; Evaluation Studies as Topic; Humans; Incisor; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Root

The objective of this study was to determine the effect of removal of the smear layer on canal obturation as measured by penetration of bacteria from a coronal direction. Fifty-four extracted human teeth were decoronated and instrumented in a uniform manner. Following instrumentation the root canals of 20 teeth were rinsed with 17% EDTA and 5.25% NaOCl to remove the smear layer before obturation. A second group of 20 teeth were flushed with NaOCl alone. The teeth of both groups were obturated with Thermafil plastic carriers and Roth's sealer. The root canals of another 10 teeth, five rinsed with EDTA and five without, were obturated with Thermafil without sealer. Two teeth serving as positive controls were instrumented but not obturated, while another set of two were sealed coronally and apically to serve as negative controls. The root surface of each tooth was sealed with nail varnish. A small chamber was thoroughly sealed around the coronal aspect of each tooth so that bacteria placed therein could move only through the obturated canal space. Each tooth was placed in a test tube containing sterile trypticase soy broth (TSB). An inoculum of Proteus vulgaris in TSB was placed in each coronal chamber at five day intervals and daily observations were made for bacterial growth in the apical reservoir for 21 days. Both positive control teeth showed bacterial penetration after 24 h. Neither of the two negative control teeth demonstrated penetration for the duration of the study. The frequency of bacterial penetration through teeth obturated with intact smear layer (70%) was-significantly greater than that of teeth from which the smear layer had been removed (30%) P < 0.05. All but one tooth obturated without sealer exhibited bacterial penetration, irrespective of the presence or absence of smear layer. Removal of the smear layer enhanced sealability as evidenced by increased resistance to bacterial penetration.

Topics: Chi-Square Distribution; Dental Leakage; Dental Pulp Cavity; Edetic Acid; Gutta-Percha; Humans; Proteus vulgaris; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite; Zinc Oxide-Eugenol Cement

We investigated oxidative potential water (OPW) for its ability to remove the smear layer using a scanning electron microscope. OPW has been studied mainly in Japan and is known to suppress bacteria and viruses without harming living systems. We found that OPW used as in irrigant during and after root canal instrumentation is as effective as 5% NaOCl or 17% EDTA for opening and keeping patent the dentinal tubules.

Topics: Acid Etching, Dental; Edetic Acid; Humans; Hydrogen-Ion Concentration; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Water

To investigate (1) the tensile bond strengths of four commercial dentin bonding systems to bovine crown and root dentin and (2) the structure of the hybrid layers for each system bonded to the two dentin substrates.. Superficial surfaces were exposed in bovine crown and root dentin. The teeth were embedded in plaster and a 3 mm diameter bonding area was demarcated. The four bonding systems used were All-Bond 2, Super-Bond D-Liner Plus, Clearfil Liner Bond II, and ProBond. Bonding procedures followed the manufacturers' instructions with the exception of Super-Bond D-Liner Plus where the primer was left in situ for 60 seconds. Tensile bond strengths were tested after 24-hour storage in 37 degrees C deionized water. Specimens were also prepared for SEM observation of the hybrid layer, after treatment with 10% phosphoric acid, and 10% phosphoric acid and 5% sodium hypochlorite.. Statistically lower bond strengths to crown dentin when compared with root dentin were observed for All-Bond 2, whereas Liner Bond II showed the opposite (P < 0.01). Both ProBond and Super-Bond D-Liner Plus showed no statistical differences between crown and root dentin (P > 0.05). Hybrid layers could be observed for All-Bond 2, Liner Bond II and Super-Bond D-Liner Plus, with no apparent differences between the hybrid layers of crown and root dentin. In the case of ProBond, where the smear layer was not removed during the priming stage, it appeared that the primer had infiltrated and caused hybridization of the smear layer. The differences in bond strength were thought to be related to the different bonding mechanisms of each material, as well as possible variations in the crown and root dentin substrates.

Topics: Acid Etching, Dental; Animals; Cattle; Composite Resins; Dental Bonding; Dentin; Dentin-Bonding Agents; Humans; Materials Testing; Mechanics; Methacrylates; Microscopy, Electron, Scanning; Phosphoric Acids; Smear Layer; Sodium Hypochlorite; Surface Properties; Tensile Strength; Tooth Crown; Tooth Root

The aim of this study was to determine the structure and the ultrastructure of the organo-mineral coating retained by endodontic reamers. Premolars extracted for orthodontic reasons were instrumented using Rispi Micromega reamers mounted on a counterangle Giromatic. One group of premolars was instrumented without irrigation, a second group was instrumented with irrigation using physiological saline, and a third group was instrumented with irrigation using Dakin. After instrumentation, the specimens were observed by scanning electron microscopy. Two microscopic techniques were used for each specimen. Secondary electron imaging was used to examine the amount of material adhering to the surfaces of the Rispi reamers after instrumentation, whereas backscattered electron imaging was used to determine the variation in the organo-mineral composition of the smear layer adhering to the reamers. The deeper layer adhering to the surface of the reamers was predominantly organic in nature no matter which instrumentation or irrigation technique was used.

Topics: Equipment Contamination; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Chloride; Sodium Hypochlorite; Therapeutic Irrigation

The purpose of this pilot study was to investigate some of the clinical variables in ultrasonic endodontics. forty extracted human teeth with a single, straight root 21-25 mm in length were prepared using combinations of the following variables: hand or ultrasonic instrumentation; apical seat prepared to file sizes 35, 40, 45 or 50; 1 ml of water, 4% sodium hypochlorite or EDTAC as irrigant between each instrument size; three brands of ultrasound generator and inserts; a 'low', 'medium' or 'high' effective power output; a tuned or untuned circuit; post-instrumentation ultrasonic irrigation with either 4% sodium hypochlorite, EDTAC, or the two used in sequence. The specimens were viewed in a scanning electron microscope and scored for the presence or absence of a smear layer at levels < 1 mm, 5 mm and 10 mm from the apical seat. The most effective combination, as tested, was hand instrumentation to file size 40 with 1 ml EDTAC irrigation between each instrument size, supplemented by intermittent flush irrigation with EDTAC with ultrasound then 4% sodium hypochlorite with ultrasound. This technique left a minimum smear layer restricted to the apical seat. Other combinations of instrumentation and irrigation were not consistent in their effectiveness.

Topics: Dentin; Edetic Acid; Evaluation Studies as Topic; Humans; Microscopy, Electron, Scanning; Pilot Projects; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy

This study compared in vitro the debridement ability of a 3% sodium hypochlorite with a new quaternary ammonium derivative, a 0.5% Bardac-22 solution, in the apical third of freshly extracted teeth with straight root canals. Root canals were instrumented sequentially from size 10 to size 35 using alternatively hand and ultrasonic files. When the hand file was loose in the canal, the ultrasonic instrument of the same size was operated at working length for 30 s, delivering 15 ml of the selected solution. Both solutions were able to flush out pulpal debris from the canal space. At the apical end of the preparation, sodium hypochlorite left a thicker smear layer than Bardac-22 did. The quaternary ammonium derivative easily dissolved the inorganic portion of the smear layer, but did not dissolve proteins as well as sodium hypochlorite.

Topics: Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Quaternary Ammonium Compounds; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Surface-Active Agents; Ultrasonic Therapy

The purpose of this study was to investigate the use of 4 per cent sodium hypochlorite and 15 per cent EDTAC, either alone or in conjunction, as irrigants during hand instrumentation and ultrasonic irrigation of the root canal. Thirty-six extracted human teeth, each with a single, straight root 21-25 mm long were hand-instrumented through a clinical access cavity to file size 40. One millilitre of the test irrigant was used after each instrument size. Canal debridement was completed with an intermittent flush irrigation technique with one or both of the test irrigants activated by ultrasound at a medium effective power output. The specimens were sectioned longitudinally, viewed in a scanning electron microscope and scored for the presence or absence of debris and smear layer at levels less than 1 mm, 5 mm, and 10 mm from the apical seat. Under the conditions of this experiment the most effective regime was irrigation with 1 mL EDTAC after each instrument size, followed by two 30 second exposures to ultrasound+EDTAC then four 30 second exposures to ultrasound + 4 per cent sodium hypochlorite. The specimens in this group were free from retained pulp tissue and superficial smear layer, had the lowest debris scores at the < 1 mm and 5 mm levels, and the lowest total debris score. All of the techniques tested produced smear-free canals at the 10 mm level.

Topics: Dental Pulp; Dental Pulp Cavity; Dentin; Drug Combinations; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation; Ultrasonic Therapy

The adhesion of cements to root canal surfaces is a crucial factor for strengthening non-vital teeth--weakened due to extensive loss of tooth structure--by cemented posts. The aim of this study was to determine the tensile strength of a glass ionomer cement (Ketac-Cem) on root canal walls following pretreatment with conditioners. Upon cleaning and shaping, 56 straight root canals--divided into seven groups--were conditioned with one of the following solutions: NaOCl (1%) + EDTA (20%), H3PO4 (37%), HNO3 (2.5%), citric acid (6%), polyacrylic acid (10% and 20%) and NaCl (0.9%) as control. Standardized dentine cylinders were prepared out of the coronal half of each root perpendicular to the root axis and subsequently split. The exposed root canal areas were coated with Ketac-Cem. Using an universal testing machine a tensile force was applied to Ketac-Cem up to fracture. Pretreatment with EDTA-NaOCl provided the strongest bond strength (2.2 MPa). The median values for the other conditioning solutions ranged from 1.2 to 1.9 MPa. The significantly weakest bond (0.5 MPa) was recorded for NaCl. The elimination of the smear layer appeared to be an essential factor in order to improve the adhesion.

Topics: Acid Etching, Dental; Analysis of Variance; Citrates; Citric Acid; Dental Bonding; Dental Pulp Cavity; Dentin; Dentin-Bonding Agents; Edetic Acid; Glass Ionomer Cements; Humans; Magnesium Oxide; Materials Testing; Microscopy, Electron, Scanning; Nitric Acid; Phosphoric Acids; Polycarboxylate Cement; Root Canal Filling Materials; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Tensile Strength; Zinc Oxide

An in-vitro study was designed to compare dentin wall adaptation of Multiphase gutta-percha root canal obturation technique versus high temperature thermoplasticized gutta-percha (Obtura) in the presence and absence of smear layer. Forty single rooted teeth with straight canals were used. After decapitation roots were divided into two equal groups. Group (I) received final irrigation with EDTA and Sodium hypochlorite (NaOCI) to remove the smear layer, while roots in Group (II) were irrigated with NaOCI alone. Each group was then subdivided into two subgroups to represent the two filling techniques. Teeth were sectioned longitudinally and viewed under scanning electron microscope. Multiphase gutta-percha showed excellent adaptation to canal wall, specially in the absence of smear layer and displayed a homogeneous mass with little amount of voids than the Obtura system.

Topics: Dental Marginal Adaptation; Dentin; Disinfectants; Edetic Acid; Glass Ionomer Cements; Gutta-Percha; Hot Temperature; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Random Allocation; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite

The aim of this investigation was to study the influence of three irrigation procedures on the composition, structure, and aspect of the smear layer within root canals. Three homogeneous groups were prepared without irrigation, with physiological serum, or with Dakin (dilute, neutral solution of sodium hypochlorite). Root canals were instrumented with Rispi Reamers mounted on a counterangle Giromatic. The irrigating solution was delivered with an endodontic irrigation needle. Modifications were observed by scanning electron microscope using secondary electron imaging and backscattered electron imaging. Instrumentation without irrigation produced a very thick smear layer that appeared in backscattered electron imaging as a compact assembly or organic and inorganic components. Instrumentation using Dakin produced canal walls that were less smeared, and the pockets of debris remaining were smaller in size than when using physiological serum. When the root canals were irrigated, the smear layer appeared as a double layer, one superficial and the other deep. The layers were predominantly inorganic with Dakin.

Topics: Blood; Dental Pulp Cavity; Dentin; Electron Probe Microanalysis; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Therapy; Scattering, Radiation; Smear Layer; Sodium Hypochlorite

The purpose of this study was to evaluate the influence of six treatments on the dispersive, acid, and base components of the free surface energy of dentin.. Occlusal dentin surfaces were polished with 4000 grit abrasive paper, washed and air dried. Characteristics of the surface energy were calculated by measuring contact angles of the four following liquids:alpha-bromonaphtalene, glycerol, ethylene glycol, and water. The dentin was then treated with aqueous solutions containing: (1) oxalic acid and glycine (OX/GLY),(2) oxalic acid, glycine, and HEMA (OX/GLY/HEMA), (3) phosphoric acid (PA), (4) maleic acid (MA),(5) EDTA, or (6) NaCIO. After treatment, washing and air drying, the energy characteristics of the samples were evaluated again.. Three kinds of wetting behavior were observed: an increase (OX/GLY/HEMA), a stabilization (PA, NaCIO) or a decrease (OX/GLY, MA, EDTA) of the wettability of the dentin surface. The calculations demonstrated that dentin surfaces are basic.. This study of the evolution of the surface energy components gave information on adhesion mechanisms involving hydrophilic and hydrophobic interactions. The results may be helpful in the formulation of conditioners and primers.

Topics: Acid Etching, Dental; Analysis of Variance; Chemical Phenomena; Chemistry, Physical; Dentin; Edetic Acid; Glycine; Hydrogen-Ion Concentration; Maleates; Matched-Pair Analysis; Methacrylates; Oxalates; Oxalic Acid; Phosphoric Acids; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Surface Properties; Surface Tension; Thermodynamics; Wettability

During canal preparation, the repeated passage of instruments provokes the formation of smear on the surface of the dentin. It is advisable to eliminate that, so as to increase antisepsis and filling impermeability. This is obtained by means of an irrigation, using a chelate compound of 6% citric acid for 60 seconds, at the end of the preparation.

Topics: Bacterial Adhesion; Citrates; Citric Acid; Dentin; Edetic Acid; Humans; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

The effect of six endodontic irrigants on smear layers created by hand instrumentation was evaluated in vitro in the middle and apical sections of 53 root canals. The irrigants evaluated were: 1% and 5% sodium hypochlorite, a combination of 24% phosphoric acid and 10% citric acid, 0.2%, 17%, and 3% ethylenediaminetetraacetic acid. After instrumentation and treatment with the respective irrigants, the root canal specimens were examined by scanning electron microscopy to determine the presence or absence of smear layer. The two sodium hypochlorite solutions did not remove the smear layer, even when 5% sodium hypochlorite was scrubbed on the dentinal walls. The 0.2% ethylenediaminetetraacetic acid solution was more effective than sodium hypochlorite, but it did not completely remove the smear layer, especially at the orifices of the dentinal tubules. The other three solutions effectively removed the smear layer, but no significant difference was found between them (p > 0.05). The solution of 3% ethylenediaminetetraacetic acid was as effective as phosphoric-citric acid and 17% ethylenediaminetetraacetic acid. Ethylenediaminetetraacetic acid, however, did not show the marked demineralizing effect on the dentinal walls and tubules as the acidic solution.

Topics: Adult; Chlorhexidine; Citrates; Citric Acid; Drug Combinations; Edetic Acid; Humans; Middle Aged; Phosphoric Acids; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

The adhesion of a strain of Streptococcus sanguis (NCTC 7863) to the root canal dentin of bovine incisors was evaluated. Samples (104) were prepared and smear layer was created on the root canal surface with a tungsten carbide bur. The samples were divided into four groups, one of them serving as a control sample and the other three each receiving a different treatment: 6% citric acid for 2 min (group 3), 6% citric acid for 2 min + 6.25% sodium hypochlorite for 1 min (group 2), 6% citric acid for 10 min (group 4). After sterilization, they were incubated, and adhesion was assessed by direct examination using a scanning electron microscope. The use of irrigation solutions significantly reduced the adhesion in the latter two groups only, with a reduction of 15% (group 2) and 18.7% (group 4) in the number of bacteria.

Topics: Animals; Bacterial Adhesion; Cattle; Citrates; Citric Acid; Colony Count, Microbial; Dental Pulp Cavity; Dentin; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Streptococcus sanguis; Surface Properties; Time Factors

A variety of methods have been used to evaluate the cleanliness of root canals after endodontic preparation and irrigation. Few irrigation agents other than sodium hypochlorite (NaOCl) have been tested in conjunction with endosonics. The purpose of this study was to examine the cleaning ability of water, NaOCl, Hibiscrub and a biological washing liquid when used as intracanal irrigants, with and without endosonics. Two methods of evaluation were employed to assess the root canal cleanliness after endodontic preparation. A total of 56 teeth, divided into eight groups, were prepared manually using the step-down technique. Each irrigating agent was used in two experimental groups, with and without endosonics. Two additional teeth which received neither instrumentation nor irrigation served as the controls. The teeth were split longitudinally and the state of cleanliness of the root canal was assessed by scoring the amount of stained organic debris and smear layer. It was demonstrated that the results of debris and smear layer scoring were significantly influenced by the type of irrigant and whether endosonics had been used. All agents exhibited similar cleaning ability when introduced manually. With endosonics, NaOCl yielded significantly less stainable debris (P < 0.05) than the other groups which showed no significant difference. The ability to remove the smear layer was enhanced, but at some distance short of the working length, by endosonics for all irrigants tested. None of the solutions tested was able to produce a canal wall that was free of smear layer.

Topics: Chi-Square Distribution; Chlorhexidine; Dental Cavity Preparation; Drug Combinations; Humans; Lipids; Observer Variation; Peptide Hydrolases; Polyphosphates; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Surface-Active Agents; Ultrasonic Therapy

The effectiveness of an experimental Nd:YAG laser fiberoptic delivery system was compared with conventional methods for its ability to cleanse and shape the root canal space in vitro. Thirty-two teeth were divided into two groups. In the first group, the canals were instrumented with K files, in the second the initial preparation was done with a K file and completed with a laser beam. Scanning electron microscopic evaluations showed that preparation with a laser beam is possible and results in an improvement in the cleanliness of the canal walls when compared with conventional techniques.

Topics: Dental Pulp Cavity; Dentin; Equipment Design; Humans; Laser Therapy; Lasers, Solid-State; Microscopy, Electron, Scanning; Optical Fibers; Pliability; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Tooth Apex

Sodium hypochlorite (NaOCl) has been recommended for irrigation during root canal preparation. This investigation used scanning electron microscopy to examine instrumented and uninstrumented surfaces in the middle third of root canals following the use of several concentrations of NaOCl (5.25%, 2.5%, 1.0%, and 0.5%). NaOCl was delivered with either an endodontic irrigation needle or an ultrasonic device. All of the concentrations of NaOCl with either delivery system were very effective in flushing out loose debris from the root canals. A smear layer with some exposed dentinal tubules was seen on all instrumented surfaces regardless of concentration of NaOCl or irrigation device. NaOCl in concentrations of 5.25%, 2.5%, and 1% completely removed pulpal remnants and predentin from the uninstrumented surfaces. Although 0.5% NaOCl removed the majority of pulpal remnants and predentin from the uninstrumented surfaces, it left some fibrils on the surface.

Topics: Bicuspid; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite

This study compared the capability of three composite resin cements to sustain a standard endodontic dowel. All of the systems incorporated some form of smear layer removal on the dentin of the endodontic channel. One system that used a methyl ethyl ketone drying agent provided inadequate clinical resistance to dislodgment of 5.4 DaN. A second cementing system that used only smear layer removal resisted loads at 54.7 DaN. The third cementing regimen that included a surface-initiated dentinal adhesive and smear layer removal recorded retention of 77.4 DaN. This study supported the concept that passively cemented dowels with composite resin can be as effective as actively seated dowels.

Topics: Acrylic Resins; Bisphenol A-Glycidyl Methacrylate; Boron Compounds; Butanones; Cementation; Chlorides; Citrates; Citric Acid; Composite Resins; Dental Bonding; Dental Cements; Dental Implantation, Endosseous, Endodontic; Edetic Acid; Ferric Compounds; Humans; Methacrylates; Methylmethacrylates; Polyethylene Glycols; Polymethacrylic Acids; Prosthesis Failure; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Stress, Mechanical

Adaptation of paste filling in primary teeth irrigated with different solutions were studied in vitro. Irrigants being evaluated were EDTA with NaOCl, NaOCl with H2O2 and glutaraldehyde. ZOE paste was used as a root canal filling. Examination was made with SEM. Insufficient adaptations were found in all groups.

Topics: Child, Preschool; Dentin; Edetic Acid; Glutaral; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Obturation; Smear Layer; Sodium Hypochlorite; Tooth, Deciduous; Zinc Oxide-Eugenol Cement

The root canals of 30 extracted human teeth with single canals were prepared biomechanically with hand instruments using a flaring technique. Three different irrigation regimes were used, with and without ultrasonic activation of a root canal file. The six irrigation sequences used in this study were as follows: Savlon, Savlon with ultrasound, EDTAC/NaOCl/EDTAC, EDTAC/NaOCl/EDTAC with ultrasound, NaOCl/EDTAC/NaOCl, and NaOCl/EDTAC/NaOCl with ultrasound. Scanning electron microscopic (SEM) examination of the prepared root canal walls showed a complete smear layer when Savlon was used. Ultrasound reduced the amount of smear with Savlon, but did not do so significantly with the other irrigation regimes. The most effective irrigation regime for removing smear layer and other debris was EDTAC/NaOCl/EDTAC. In all groups there was a significant decrease in cleaning efficiency as the apical end of the canal was approached.

Topics: Cetrimonium Compounds; Chi-Square Distribution; Chlorhexidine; Dental Pulp Cavity; Dentin; Drug Combinations; Edetic Acid; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy

The purpose of this study was to quantitate the sequential effects of endodontic procedures on the permeability of human root dentin in vitro. Forty single-rooted teeth were used. Both the crown and the apical 2 mm of the root were removed. The hydraulic conductance of the root before and after various endodontic procedures was measured using a fluid filtration method. Measurements were also made of dentin thickness, intracanal diameter changes, and changes in intracanal surface area. The results showed that instrumentation by K files alone or in combination with Gates Glidden drills did not alter radicular dentin permeability when the cementum remained intact. After removing the cementum, the creation of a smear layer and smear plugs on the canal surface tended to offset the expected increase in dentin permeability created by increasing the intracanal surface area and decreasing root dentin thickness. EDTA treatment inside the instrumented canal to remove the smear layer did not increase permeability significantly. The use of K files followed by Gates Glidden drills tended to remove more cervical dentin, increased the intracanal surface area, and increased the hydraulic conductance of root dentin more than the use of K files alone.

Topics: Dental Cementum; Dentin Permeability; Dentin, Secondary; Edetic Acid; Humans; Hydrostatic Pressure; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Tooth Root

The purpose of this study was to compare the effect of various irrigating solutions and irrigating debris and the smear layer from the walls of instrumented root canals. 20 single-rooted teeth were biomechanically instrumented to size 40 K-file using sterile saline. And then the teeth were divided into 4 groups and 5 teeth in each group. Groups were irrigated as follows: Group 1: Teeth were irrigated with 20 ml of sterile saline. Group 2: Teeth were irrigated with 10 ml of 3% H2O2 and 10 ml of 2.5% NaOCl using the syringe. Group 3: Teeth were irrigated with 10 ml of 3% H2O2 and 10 ml of 2.5% NaOCl using the ENAC. Group 4: Teleth were irrigated with 10 ml of 17% EDTA and 10 ml of 2.5% NaOCl using the Endo-mate. All specimens were viewed at the cervical, middle, and apical thirds of the root canals for evaluation of the cleaning effect with the scanning electron microscope. The results were as follows: 1. The Endo-mate with EDTA and NaOCl solutions was the most efficient in cleaning the cervical and middle thirds of the root canal. 2. There was no difference between the irrigating solutions and irrigating systems in the cleaning effect at the apical third of the root canal.

Topics: Edetic Acid; Humans; Hydrogen Peroxide; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Therapeutic Irrigation

After giving a brief illustration of the complex morphology of the root canal system, the Authors discuss the use of ultrasound in Endodontics. Following a critical evaluation of the literature and of the mechanisms of ultrasonic instruments, they illustrate their experience through a wide selection of S.E.M. photographs of teeth treated in vitro with sodium hypochlorite at various concentrations and for different lengths of time. They demonstrate the synergistic action between ultrasound and irrigation solutions, and conclude that the best results are with 2.5% hypochlorite for 1 minute.

Topics: Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy

The aim of this paper is to show by means of S.E.M. examination the amount of pulp tissue removed from the root canal walls by two different techniques of irrigation, namely manual and subsonic, employing the same root canal instrumentation technique.

Topics: Dental Cavity Preparation; Dental Pulp Cavity; Dentin; Humans; Microscopy, Electron, Scanning; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Ultrasonic Therapy