sodium-hypochlorite and Tooth-Fractures

The purpose of this in vitro study was to assess the influence of MetaSEAL and AH Plus on the resistance to vertical root fracture of endodontically treated teeth when either the matched-taper single-cone or lateral condensation technique was used.. Ninety extracted single-canal mandibular premolar teeth were sectioned, leaving a standard root length of 13 mm. The buccolingual and mesiodistal diameters were measured, and the teeth were randomly divided into 6 groups (n = 15). There were no statistically significant differences between the groups in terms of the diameters. In group 1, no instrumentation or obturation was performed. The rest of the roots were chemomechanically prepared with nickel-titanium ProTaper rotary instruments up to size F3 at the working length. Group 2 was left unobturated. Groups 3 and 4 were obturated with AH Plus used with the matched-taper single-cone and lateral condensation techniques, respectively. In groups 5 and 6, MetaSEAL was used instead of AH Plus. All of the roots were mounted vertically in self-curing acrylic resin blocks that exposed 8 mm of the coronal part. Then the roots were subjected to a vertical loading force (1 mm/min). The force required to produce a fracture was recorded in newtons. The data were analyzed by using Kruskal-Wallis and post hoc Dunn multiple comparison tests (P < .05).. Although we did not detect statistical significance, there was a substantial difference between the fracture resistance values of the intact and instrumented but not obturated roots. The groups in which AH Plus and MetaSEAL were used with the matched-taper single-cone technique showed significantly higher fracture resistance values than the instrumented but not obturated roots (P < .05). There were no significant differences between the groups submitted to the matched-taper single-cone technique. The force required to fracture the roots in the group treated with AH Plus and the lateral condensation technique was similar to that required to fracture intact roots, whereas the group treated with MetaSEAL and the lateral condensation technique revealed comparable values to the instrumented but not obturated roots.. When used with the matched-taper single-cone technique, MetaSEAL and AH Plus have the potential to reinforce endodontically treated teeth.

Topics: Bicuspid; Dental Stress Analysis; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Humidity; Materials Testing; Methacrylates; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Sodium Hypochlorite; Stress, Mechanical; Temperature; Time Factors; Tooth Fractures; Tooth Root; Tooth, Nonvital

The objective of this study was to evaluate the effect of ethylenediaminetetraacetic acid (EDTA) on root fracture with respect to various concentrations at different time exposures.. A total of 48 mandibular incisors were selected. Eight nonprepared roots were selected as a negative control. The remaining 40 specimens were instrumented with rotary files and randomly assigned to one of the following groups for final irrigation: (1) 10 mL distilled water for 10 minutes (positive control); (2) 10 mL of 17% EDTA for 1 minute + 10 mL of 1% NaOCl for 1 minute; (3) 10 mL of 5% EDTA for 1 minute + 10 mL of 1% NaOCl for 1 minute; (4) 10 mL of 17% EDTA for 10 minutes + 10 mL of 1% NaOCl for 1 minute; (5) 10 mL of 5% EDTA for 10 minutes + 10 mL of 1% NaOCl for 1 minute. Thereafter, the root canals were filled by using AH26 root canal sealer with a single-cone technique. The specimens were loaded vertically at 1 mm/min crosshead speed until vertical root fracture occurred. Results were evaluated statistically with 1-way analysis of variance and Student's t test.. Statistically significant differences were detected among the groups (P < .05). The highest mean fracture resistance was obtained from the group treated with 5% EDTA for 10 minutes. This is about 2 times more than the weakest mean fracture resistance, which was obtained from the 17% EDTA-10 minute group.. The fracture resistances of endodontically treated roots were found to be differently affected by the various concentrations of EDTA at different time exposures.

Topics: Bismuth; Dental Stress Analysis; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Humidity; Incisor; Materials Testing; Microscopy, Electron, Scanning; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silver; Sodium Hypochlorite; Stress, Mechanical; Time Factors; Titanium; Tooth Fractures; Tooth Root; Tooth, Nonvital

The aim of this study was to evaluate the ex vivo effects of root canal preparation, filling techniques, and mechanical cycling (MC) on the incidence of dentin defects and vertical root fractures (VRFs).. Seventy extracted single-rooted teeth were divided into 6 groups. The first 2 groups were the unprepared and unprepared/MC groups. The other groups were prepared by using Gates Glidden drills and ProTaper Universal files up to F3 and were grouped according to the following: prepared teeth and the absence of root canal filling, passive technique, lateral compaction, and Tagger's hybrid technique. All of the groups except the unprepared group were subjected to MC (1,000,000 cycles, 90 N, 4 Hz, 37°C). The roots were then sectioned horizontally at 3, 6, and 9 mm from the apex and observed under a ×10 stereomicroscope. The defects were categorized as no defect, vertical root fracture, and other defects. The differences between the groups were analyzed by using the Fisher exact and χ(2) tests.. MC by itself did not influence the incidence of dentinal defects (P > .05, between the unprepared and unprepared/MC groups). The filled groups presented a similar incidence of other defects (P > .05), although VRFs were observed only when the MC was associated with pressure filling techniques (the lateral compaction and Tagger's hybrid groups).. MC by itself did not induce VRF. When associated with apical pressure filling techniques, however, VRF occurred in 13.3% (lateral compaction) and 33.3% (Tagger's hybrid) of the cases.

Topics: Bisphenol A-Glycidyl Methacrylate; Composite Resins; Dental Materials; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Edetic Acid; Epoxy Resins; Equipment Design; Gutta-Percha; Humans; Humidity; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Sodium Hypochlorite; Stress, Mechanical; Temperature; Time Factors; Tooth Apex; Tooth Fractures; Tooth Root

Unresolved controversy exists concerning the optimum restorative material to reinforce the thin-walled roots of endodontically treated teeth to improve their fracture resistance under occlusal load. This study evaluated the effectiveness of irrigant, dowel type, and root-reinforcing material on the fracture resistance of thin-walled endodontically treated teeth.. The root canals of 140 maxillary central incisors were enlarged and equally divided into seven groups according to the canal irrigant: no irrigant (control), 5% hydrogen peroxide, 5% sodium hypochlorite, a combination of 5% hydrogen peroxide and sodium hypochlorite, 15% ethylenediaminotetraacetic acid (EDTA), 10% lactic acid, or 20% lactic acid. Within each group, root canals were lined with composite resin (PermaFlo) or glass ionomer cement (Fuji II LC). A light-transmitting plastic dowel (Luminex) was used to create space for a quartz fiber-reinforced dowel (Aestheti Post) or a titanium alloy dowel (ParaPost XH) and to cure the restorative materials. Following dowel cementation and restoration of the roots with composite core, the teeth were submitted to fracture resistance testing, and data were analyzed with 3-way ANOVA followed by Ryan-Einot-Gabriel-Welsch Multiple Range Test (α= 0.05).. Fracture resistance values were significantly different among irrigants, restorative materials, and their interaction (p < 0.001); however, the dowel type was not significantly different (p= 0.51).. Thin-walled roots that had the smear layer removed with lactic acid and that were then lined with composite resin had a higher fracture resistance.

Topics: Biomechanical Phenomena; Composite Resins; Dental Alloys; Dental Materials; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Edetic Acid; Glass Ionomer Cements; Gutta-Percha; Humans; Hydrogen Peroxide; Incisor; Lactic Acid; Materials Testing; Microscopy, Electron, Scanning; Post and Core Technique; Quartz; Resins, Synthetic; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Sodium Hypochlorite; Stress, Mechanical; Titanium; Tooth Fractures; Tooth, Nonvital

There have been varied results from studies comparing postendodontic fracture resistance between teeth obturated with Resilon or gutta-percha. This study was performed to evaluate the fracture resistance of roots obturated by using Resilon (RealSeal system) or gutta-percha (with AH Plus sealer).. Eighty extracted human mandibular single-rooted premolars stored in 10% formalin were used in the study. They were prepared by using a crown-down technique, debrided with NaOCl, ethylenediaminetetraacetic acid, and sterile water and divided into 4 groups. Obturation was performed by using the lateral condensation method. The negative control group consisted of unfilled specimens, and the positive control group consisted of those obturated with flowable, dual-cure composite resin. All root specimens were stored for 2 weeks in 100% humidity to allow complete setting of the sealer. Each specimen was mounted in acrylic in a polyvinyl ring and tested for fracture resistance with the Universal testing machine. The loading fixture of the machine was mounted with its spherical tip aligned with the center of the canal opening of each root. A vertical loading force was applied until it fractured the root. The force values were subjected to statistical analysis including analysis of variance and Fisher least significant difference testing.. Teeth obturated with Resilon were more resistant to fracture than those obturated with gutta-percha. The difference was found to be highly significant (P=.00001).. Resilon increased the resistance to fracture of single-rooted teeth in vitro.

Topics: Bicuspid; Composite Resins; Dental Stress Analysis; Edetic Acid; Epoxy Resins; Gutta-Percha; Humans; Humidity; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Sodium Hypochlorite; Stress, Mechanical; Time Factors; Tooth Fractures; Tooth Root

To evaluate 1% NaOCl treatment and two resin luting agent effects on compressive strength recovery in composite onlays on primary teeth and to analyze the fractures type.. Forty sound primary molars crowns were prepared in the standard machine and randomly divided into four groups (n=10): G1 (1% NaOCl/ 30 min+EnForce); G2 (without 1% NaOCl EnForce); G3 (1% NaOCl/ 30 min+Rely X); G4 (without 1% NaOCl+Rely X). The onlays were made using Z250 composite on plaster models. Ten sound teeth were used as control group (CG). All groups were submitted to compression mechanic test in a universal test machine INSTRON at 1mm/min cross-head speed. After that, the data (kgf) were submitted to ANOVA test (alpha=0.05). Finally, the fracture types were classified in a crescent scale (1-5) related with severity degree and submitted to Fisher's Exact Test (p<0.05). Scanning electronic microscope analysis was done in order to illustrate the fractures sites.. The values of compressive strength of experimental groups did not differ each others neither from control group (p>0.05). The results from fracture type showed that types 5 and 4 fractures (most severe) present the highest percentage to experimental groups. Conversely, the CG showed higher percentage of fracture types 2 and 3.. This research found that the composite onlays recovered the compressive strength compared to sound teeth, regardless of the substrate treatment and cement agent used. Nevertheless, no group showed similar type of fractures to CG, which had more frequency of less severe fracture types.

Topics: Acetone; Acid Etching, Dental; Bisphenol A-Glycidyl Methacrylate; Composite Resins; Compressive Strength; Dental Cavity Preparation; Dental Cements; Dental Materials; Dental Stress Analysis; Dentin-Bonding Agents; Disinfectants; Glass Ionomer Cements; Humans; Inlays; Microscopy, Electron, Scanning; Molar; Polymethacrylic Acids; Resin Cements; Sodium Hypochlorite; Tooth Crown; Tooth Fractures; Tooth, Deciduous

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

Continuous chelation involves the simultaneous use of sodium hypochlorite and a chelating agent. Given the combination of a proteolytic agent and a demineralising chelator, this study aimed to investigate whether mixtures containing the weak chelators etidronate or clodronate and sodium hypochlorite could adversely affect the mechanical strength of teeth compared to the sequence sodium hypochlorite/EDTA/sodium hypochlorite. Matching pairs of bovine teeth were tested on a universal testing machine, and the compressive load at fracture was recorded. One root from each pair was prepared with the sequence, and the matching tooth was prepared with either water, the clodronate mixture or the etidronate mixture. No differences in load at fracture were seen between either mixture and the sequence. However, loads were higher in the teeth irrigated with water compared to the sequence. The results indicated that the continuous chelation mixtures did not alter tooth mechanical properties compared to the standard sequence.

Topics: Animals; Cattle; Chelating Agents; Dental Stress Analysis; Root Canal Irrigants; Sodium Hypochlorite; Tooth Fractures

The aim of the present work was to measure the fracture resistance of endodontically treated teeth that were apicoected with different procedures. Seventy-two extracted human maxillary anterior teeth were included in this study. The specimens were randomly assigned to three main groups according to the apical surgery procedures and then two subgroups according to the irrigation protocols during root canal treatment and total of six groups were obtained (n = 12). Group 1: served as a control and apical surgery process was not performed in this group. Group 2: apical surgery process was performed with tungsten carbide fissure bur Group 3: apical surgery process was performed with Er:YAG laser. Subgroup a: In this group, the specimens were irrigated with %5 NaOCl. Subgroup b: 15% EDTA solution was filled into the root canal and then agitated using a 1.5 W/100 Hz diode laser. The specimens were filled and mounted in acrylic resin blocks and compression strength test was performed. Statistical analysis was performed using two-way ANOVA. The statistical analysis revealed that there were no statistical significant differences between apical surgery procedures (groups 1, 2, and 3) (p < 0.05). Apical resection procedures did not affect the fracture resistance Significant differences were determined between the subgroups (p < 0.05). Agitation of the EDTA with the diode laser reduced the fracture resistance of the specimens. The different canal irrigation techniques altered resistance to fracture; however, apical surgery procedures did not altered the resistance to fracture when compared with the control group.

Topics: Adult; Apicoectomy; Dental Pulp Cavity; Edetic Acid; Humans; Lasers, Solid-State; Middle Aged; Root Canal Irrigants; Root Canal Therapy; Sodium Hypochlorite; Tooth Fractures; Tooth Root; Tooth, Nonvital

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

This study aimed to evaluate the effects of different synthetic and natural-derived root canal irrigants (6% sodium hypochlorite [NaOCl], 6% calcium hypochlorite [Ca(OCl)

Topics: Calcium Compounds; Dental Stress Analysis; Dentin; Grape Seed Extract; Humans; Materials Testing; Mechanical Phenomena; Root Canal Irrigants; Sodium Hypochlorite; Stress, Mechanical; Tensile Strength; Tooth; Tooth Fractures

The aim of the study was to assess the influence of external root anatomy, time of irrigation and the rate of mechanical enlargement of root canals on root fracture resistance. Thirty six bovine teeth were decoronated and divided into 2 groups: with round and oval forms of axial root slices. The root canals were mechanically enlarged according to standard protocol and prepared for post placement. Individual cast posts were made for each tooth, the diameter of posts comprised 1/2 or 1/3 of the root diameter in different subgroups. After mechanical enlargement, the canals were irrigated with 3% sodium hypochlorite for 10 or 60 minutes in different subgroups. The teeth with posts were subjected to static vertical load by universal testing machine with the speed of 1 mm per minute. The load that had led to fracture initiation was noted. Analysis of variances was used to assess the statistical significance of the. No statistically significant differences were found between the groups with different protocols of mechanical preparation and irrigation. Teeth with round axial root slice were significantly less susceptible to fractures than ones with oval shape of axial root slice taking into consideration the protocols of mechanical preparation and irrigation.. Цель исследования: оценить влияние механической и медикаментозной обработки корневых каналов, а также формы поперечного сечения корней на их устойчивость к возникновению вертикальных трещин. В исследовании были использованы 36 бычьих зубов. Зубы были декоронированы и разделены на две группы: с овальной формой поперечного сечения и с круглой формой поперечного сечения. Корневые каналы были механически обработаны по стандартному протоколу и затем расширены стандартными развертками для изготовления индивидуальных литых штифтов таким образом, чтобы в половине корней диаметр канала составлял 1/3 ширины корня, в другой половине - 1/2 ширины корня. После механической обработки корневых каналов проводили ирригацию 3% раствором гипохлорита натрия в течение 10 или 60 мин в различных подгруппах. С помощью испытательной машины производили нагружение штифтов по вертикальной оси со скоростью 1 мм в минуту. Фиксировали нагрузку (Н), при которой происходило образование трещины корня. Для определения статистической достоверности полученных результатов применяли дисперсионный анализ. Не было обнаружено статистически достоверных различий между группами с различной продолжительностью медикаментозной обработки и различной степенью расширения корневых каналов. Различия между группами с овальной и круглой формами поперечного сечения корней с учетом варианта механической и медикаментозной обработки были достоверны.

Topics: Animals; Cattle; Dental Stress Analysis; Pilot Projects; Root Canal Preparation; Sodium Hypochlorite; Therapeutic Irrigation; Tooth Fractures; Tooth Root

Recently, we reported that in mandibular molars contracted endodontic cavities (CECs) improved fracture strength compared with traditional endodontic cavities (TECs) but compromised instrumentation efficacy in distal canals. This study assessed the impacts of CECs on instrumentation efficacy and axial strain responses in maxillary molars.. Eighteen extracted intact maxillary molars were imaged with micro-computed tomographic imaging (12-μm voxel), assigned to CEC or TEC groups (n = 9/group), and accessed accordingly. Canals were instrumented (V-Taper2H; SSWhite Dental, Lakewood, NJ) with 2.5% sodium hypochlorite irrigation, reimaged, and the proportion of the modified canal wall determined. Cavities were restored with bonded composite resin (TPH-Spectra-LV; Dentsply International, York, PA). Another 28 similar molars (n = 14/group) with linear strain gauges (Showa Measuring Instruments, Tokyo, Japan) attached to mesiobuccal and palatal roots were subjected to load cycles (50-150 N) in the Instron Universal Testing machine (Instron, Canton, MA), and the axial microstrain was recorded before access and after restoration. These 28 molars and additional 11 intact molars (control) were cyclically fatigued (1 million cycles, 5-50 N, 15 Hz) and subsequently loaded to failure. Data were analyzed by the Wilcoxon rank sum and Kruskal-Wallis tests (α = 0.05).. The overall mean proportion of the modified canal wall did not differ significantly between CECs (49.7% ± 12.0%) and TECs (44.7% ± 9.0%). Relative changes in axial microstrain responses to load varied in both groups. The mean load at failure for CECs (1703 ± 558 N) did not differ significantly from TECs (1384 ± 377 N) and was significantly lower (P < .005) for both groups compared with intact molars (2457 ± 941 N).. In maxillary molars tested in vitro, CECs did not impact instrumentation efficacy and biomechanical responses compared with TECs.

Topics: Biomechanical Phenomena; Composite Resins; Dental Cavity Preparation; Dental Pulp Cavity; Dental Restoration, Permanent; Dental Stress Analysis; Humans; Materials Testing; Maxilla; Molar; Root Canal Irrigants; Root Canal Preparation; Sodium Hypochlorite; Stress, Mechanical; Tooth Apex; Tooth Crown; Tooth Fractures; Tooth Root; X-Ray Microtomography

The purpose of this study was to investigate the incidence of apical crack initiation and propagation in root dentin after several endodontic procedures.. Sixty intact mandibular premolars were sectioned perpendicular to the long axis at 1 mm from the apex, and the apical surface was polished. Thirty teeth were left unprepared and served as a control, and the remaining 30 teeth were instrumented with ProTaper Universal instruments (Dentsply Maillefer, Ballaigues, Switzerland) up to size F5. The root canals were filled with the single-cone technique. Gutta-percha was removed with drills of the Rebilda post system (VOCO, Cuxhaven, Germany). Glass fiber-reinforced composite fiber posts were cemented using a dual-cure resin cement. The fiber posts were removed with a drill of the post system. Retreatment was completed after the removal of the gutta-percha. Crack initiation and propagation in the apical surfaces of the samples were examined with a stereomicroscope after each procedure. The absence/presence of cracks was recorded. Logistic regression was performed to analyze statistically the incidence of crack initiation and propagation with each procedure.. The initiation of the first crack and crack propagation was associated with F2 and F4 instruments, respectively. The logistic regression analysis revealed that instrumentation and F2 instrument significantly affected apical crack initiation (P < .001). Post space preparation had a significant effect on crack propagation (P = .0004). The other procedures had no significant effects on crack initiation and propagation (P > .05).. Rotary nickel-titanium instrumentation had a significant effect on apical crack initiation, and post space preparation with drills had a significant impact on crack propagation.

Topics: Bicuspid; Dentin; Gutta-Percha; Humans; Mandible; Retreatment; Root Canal Filling Materials; Root Canal Obturation; Root Canal Preparation; Sodium Hypochlorite; Tooth Apex; Tooth Fractures; Tooth Root

In some parts of the world, revascularization may not be the most feasible treatment option for necrotic immature teeth. Therefore, apexification remains the most widely utilized treatment option for these cases. This study aimed to evaluate the fracture resistance of weakened bovine tooth roots treated with various irrigant solutions as well as long-term application of calcium hydroxide intracanal medication (ICM).. One hundred seventy bovine teeth were randomly divided into three experimental groups (n = 50) and two control groups (n = 10). Group SS was irrigated with physiologic solution; group CHX was treated with 2% chlorhexidine gel and group NaOCl was irrigated with 1% sodium hypochlorite. After instrumentation, root canals were dressed with calcium hydroxide and evaluated at different periods (15, 60, 90, 180, and 360 days). The specimens were loaded at a 45° angle to measure fracture resistance through the use of an EMIC test machine.. A decrease in fracture resistance was observed during the time of ICM dressing. The highest values of fracture resistance were observed in group SS with 15 days of ICM, not differing from the control group. Irrigation with NaOCl associated with ICM for 15 days presented the lowest fracture resistance; however, a statistically significant difference was not observed when compared with SS and CHX in the same time period. In longer periods of exposure to ICM (180 and 360 days), root canals irrigated with NaOCl and CHX showed significantly lower fracture resistance than SS (P < 0.05).. Apexification with periodic changes of calcium hydroxide medicament leads to weakness of the teeth independent of the irrigation solution used.

Topics: Animals; Apexification; Calcium Hydroxide; Cattle; Chlorhexidine; Dental Stress Analysis; In Vitro Techniques; Random Allocation; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Sodium Hypochlorite; Tooth Fractures

The purpose of this study was to evaluate the fracture strength of roots instrumented with the Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel) and the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) and filled with the cold lateral compaction technique.. In total, 50 mandibular premolar teeth were sectioned at or below the cementoenamel junction to obtain roots 13 mm in length. The roots were balanced with respect to buccolingual-mesiodistal diameters and weight. They were distributed into 4 experimental groups and 1 control group (n = 10): no instrumentation (control group), instrumentation with ProTaper rotary files but no filling (PT), instrumentation with ProTaper rotary files and filling with cold lateral compaction (PT filling), instrumentation with SAF but no filling (SAF), and instrumentation with SAF and filling with cold lateral compaction (SAF filling). AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) was used along with gutta-percha points. One week later, a vertical load was applied to the specimen's canal until fracture occurred. Data were statistically analyzed using 1-way analysis of variance (P = .05).. The mean fracture load was 244 ± 51 N for the control group, 226 ± 21 N for the PT, 242 ± 45 N for PT filling, 233 ± 14 N for the SAF, and 271 ± 44 N for SAF filling. However, the differences were not statistically significant (P > .05).. Instrumentation with the SAF or the ProTaper rotary system did not change the fracture strength of standardized roots with respect to cross-sectional diameter and weight.

Topics: Bicuspid; Biomechanical Phenomena; Dental Stress Analysis; Epoxy Resins; Equipment Design; Gutta-Percha; Humans; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Sodium Hypochlorite; Tooth Fractures; Tooth Root

Vertical root fracture is a common finding in endodontically treated teeth, notably oval roots. The aim of the present study was to determine the effect of instrumentation kinematics and the material of instrument construction of single-file systems on dentin walls and fracture resistance of oval roots.. Sixty-five roots with oval canals were allocated into a control group (n = 5) and 3 experimental groups of 20 roots each. Group WO was instrumented with the WaveOne primary file (Dentsply Maillefer, Baillagues, Switzerland), group PT-Rec was prepared with F2 ProTaper files (Dentsply Maillefer, Baillagues, Switzerland) used in a reciprocating motion, and group PT-Rot was prepared with F2 ProTaper files used in a rotation motion. For crack evaluation, half of the samples (n = 30) were embedded in acrylic resin, and the blocks were sectioned at 3, 6, and 9 mm from the apex. The sections were examined under a stereomicroscope and scored for crack presence. The other half of the specimens (n = 30) were obturated using lateral condensation of gutta-percha and AdSeal sealer (Meta Biomed Co, Ltd, Chungbuk, Korea). The specimens were then subjected to a load of 1 mm/min to determine the force required to fracture the roots.. WaveOne instruments induced the least amount of cracks and exhibited greatest resistance to fracture compared with ProTaper F2 files whether used in reciprocating or rotating motions.. The alloy from which the material is manufactured is a more important factor determining the dentin damaging potential of single-file instruments than the motion of instrumentation.

Topics: Dental Alloys; Dental Pulp Cavity; Dentin; Epoxy Resins; Equipment Design; Gutta-Percha; Humans; Motion; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Rotation; Sodium Hypochlorite; Stress, Mechanical; Tooth Apex; Tooth Fractures; Tooth Root; Tooth, Nonvital; Torque

Conservative endodontic cavity (CEC) may improve fracture resistance of teeth but compromise the instrumentation of canals. This study assessed the impacts of CEC on both variables in 3 tooth types.. Extracted human intact maxillary incisors, mandibular premolars, and molars (n = 20/type) were imaged with micro-computed tomographic imaging (20-μm resolution) and assigned to CEC or traditional endodontic cavity (TEC) groups (n = 10/group/type). Minimal CECs were plotted on scanned images. Canals were prepared with WaveOne instruments (Dentsply Maillefer, Ballaigues, Switzerland) using 1.25% sodium hypochlorite and post-treatment micro-computed tomographic images obtained. The proportion of the untouched canal wall (UCW) and the dentin volume removed (DVR) for each tooth type was analyzed with the independent-samples t test. The 60 instrumented and 30 intact teeth (negative control, n = 10/type) were loaded to fracture in the Instron Universal Testing machine (Instron, Canton, MA) (1 mm/min), and the data were analyzed with 1-way analysis of variance and the Tukey test.. The mean proportion of UCW was significantly higher (P < .04) only in the distal canals of molars with CEC (57.2% ± 21.7%) compared with TEC (36.7% ± 17.2%). The mean DVR was significantly smaller (P < .003) for CEC than for TEC in incisors (16.09 ± 4.66 vs 23.24 ± 3.38 mm(3)), premolars (8.24 ± 1.64 vs 14.59 ± 4.85 mm(3)), and molars (33.37 ± 67.71 mm(3)). The mean load at fracture for CEC was significantly higher (P < .05) than for TEC in premolars (586.8 ± 116.9 vs 328.4 ± 56.7 N) and molars (1586.9 ± 196.8 vs 641.7 ± 62.0 N). In both tooth types, CEC did not differ significantly from the negative controls.. Although CEC was associated with the risk of compromised canal instrumentation only in the molar distal canals, it conserved coronal dentin in the 3 tooth types and conveyed a benefit of increased fracture resistance in mandibular molars and premolars.

Topics: Bicuspid; Biomechanical Phenomena; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Humans; Incisor; Materials Testing; Molar; Root Canal Irrigants; Root Canal Preparation; Sodium Hypochlorite; Stress, Mechanical; Tooth Apex; Tooth Crown; Tooth Fractures; X-Ray Microtomography

Stabilizing sodium hypochlorite (NaOCl) at an alkaline pH is proposed to increase solution stability and tissue dissolution ability; however, a reduction on the flexural strength of dentin discs has been found to be a side effect. This study sought to determine whether a stabilized alkaline NaOCl reduces the fracture resistance of root canal-treated bovine teeth after root canal preparation compared with a neutral solution counterpart.. The 4 anterior incisors were removed from 20 mandibular bovine jaws, and each 1 was randomly assigned to 1 of 4 groups (20 teeth each). Teeth were prepared with a sequence of 6 K-type files. The following experimental groups received a different irrigation regimen: G1: distilled water (negative control), G2: 5% NaOCl at a pH of 7.2, and G3: 5% NaOCl at a pH of 12.8; in the positive control group (G4), teeth remained untreated. The time of contact and volume of solution were carefully standardized. After bone and periodontal ligament simulation, teeth were subjected to a fracture resistance test.. A significant difference was observed among the 4 groups tested (analysis of variance, P < .05). The 5% NaOCl groups (G2 and G3) presented significantly lower resistance to fracture than the control (G1 and G4) (Tukey test, P < .05). Both NaOCl solutions similarly reduced the fracture resistance at approximately 30% (Tukey test, P > .05). No differences were observed between positive and negative control groups (Tukey test, P > .05).. Stabilized alkaline and neutral NaOCl solutions similarly reduced the fracture resistance of root canal-treated bovine teeth by about 30%.

Topics: Alkalies; Animals; Cattle; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Hydrogen-Ion Concentration; Materials Testing; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Sodium Hypochlorite; Stress, Mechanical; Therapeutic Irrigation; Time Factors; Tooth Fractures; Tooth, Nonvital; Water

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

Regenerative endodontic treatment (RET) has been used in treating nonvital immature permanent tooth whose root formation ranged from approximately two-thirds of the full root length to almost completely developed root with open apex at least 1.1 mm in diameter according to the reported cases. However, this case report was to introduce RET in an affected tooth at an early stage of root development.. The premolar #29 in an 8-year-old girl had pulpal necrosis and apical periodontitis caused by the fracture of dens evaginatus. Its root was at the beginning of formation. Copious hemorrhagic drainage was observed after preparing of an access cavity. The canal was irrigated with 3% NaOCl solution, sterile normal saline, and chlorhexidine. Root dressing with triple antibiotic was then performed and left for 4 weeks. We used a K-file to create bleeding into the canal after flushing and drying the root canal. Mineral trioxide aggregate was carefully placed over the formed blood clot.. Clinical examination at 1, 3, 6, 9, and 12 months revealed an asymptomatic tooth. Radiographic examination revealed resolution of periapical radiolucency, increased thickening of the canal wall, and lengthening of the root, which demonstrated the continual development of the tooth root. Noticeably, the first-month postoperative radiograph showed radiopaque image in the root canal like an isolated island, which was gradually obvious during follow-up. Cone-beam computed tomography revealed that the calcification was attached with dentin wall in buccolingual direction, and the root canal was not completely obliterated.. RET is feasible for a tooth at an early stage of root development that has necrotic pulp and periapical lesion.

Topics: Aluminum Compounds; Anti-Bacterial Agents; Apexification; Bicuspid; Calcium Compounds; Calcium Hydroxide; Child; Chlorhexidine; Cone-Beam Computed Tomography; Dental Pulp Cavity; Dental Pulp Necrosis; Drug Combinations; Female; Follow-Up Studies; Humans; Odontogenesis; Oxides; Periapical Periodontitis; Regeneration; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Silicates; Sodium Hypochlorite; Tooth Fractures; Tooth Root

Inflammatory root resorption is a serious complication of dental trauma, which leads to progressive loss of the root structure. This report describes the treatment a previously traumatized young maxillary lateral incisor, severely affected by inflammatory root resorption. An 11-year-old boy presented with pain and mobility in his maxillary incisors which experienced fall trauma 2 years earlier. Radiographic examination revealed incomplete root development of the right central incisor, associated with advanced inflammatory root resorption and a periapical lesion. Following removal of a prior long-term calcium hydroxide dressing, the root canal was submitted to a 2-week irrigation regimen involving 1.25% sodium hypochlorite and 2% chlorhexidine gluconate. Thereafter, the entire root was filled with mineral trioxide aggregate. The radiographic follow up at 6 months showed arrest of root resorption and initiation of periapical healing in the absence of clinical symptoms and mobility. This was followed by advanced osseous regeneration and re-establishment of the periodontal space at 12 and 24 months. From the present case, it can be concluded that mineral trioxide aggregate obturation can be a viable option that can improve the healing outcomes in cases of severe inflammatory root resorption in young permanent teeth.

Topics: Aluminum Compounds; Bone Regeneration; Calcium Compounds; Child; Chlorhexidine; Dental Fistula; Dental Pulp Necrosis; Drug Combinations; Follow-Up Studies; Humans; Incisor; Male; Oxides; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Resorption; Silicates; Sodium Hypochlorite; Tooth Crown; Tooth Fractures; Tooth Mobility; Treatment Outcome

To evaluate ex vivo the incidence of defects in root dentine before and after root canal preparation and filling.. Eighty extracted mandibular premolars were divided equally in four groups. Group 1 was left unprepared. All other root canals were prepared using Gates Glidden drills and System GT files up to size-40, 0.06 taper at the working length. Group 2 was not filled while the canals of the other groups were filled with gutta-percha and AH26, either with a master cone and passive insertion of secondary gutta percha points (group 3) or lateral compaction (group 4). Roots were then sectioned horizontally 3, 6, and 9 mm from the apex and observed under a microscope. The presence of dentinal defects (fractures, craze lines or incomplete cracks) was noted and the differences between the groups were analysed with the Fisher's exact test.. No defects were observed in the roots with unprepared canals. The overall difference between the groups was significant (P < 0.05). Canal preparation alone created significantly more defects than unprepared canals (P < 0.05). The total number of defects after lateral compaction was significantly larger than after noncompaction canal filling.. Root canal preparation and filling of extracted teeth created dentine defects such as fractures, craze lines and incomplete cracks.

Topics: Bicuspid; Bismuth; Dental Pulp Cavity; Dentin; Drug Combinations; Epoxy Resins; Equipment Design; Gutta-Percha; Humans; Materials Testing; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Root Canal Preparation; Silver; Sodium Hypochlorite; Titanium; Tooth Fractures

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

This case report describes the treatment of a horizontal root fracture in a maxillary central incisor (tooth #8) using a triple antibiotic paste and mineral trioxide aggregate. A nonsurgical endodontic treatment was performed to a coronal root canal fragment of tooth #8. During the treatment procedure, 1% sodium hypochlorite solution was used for irrigation and a triple antibiotic paste was used as an intracanal medicament. The coronal part of the canal was obturated with mineral trioxide aggregate totally. At follow-up examination after 12 months, the tooth was asymptomatic and radiographically showed repair of the fracture region. Healing was achieved without any need for further interventions.

Topics: Aluminum Compounds; Anti-Bacterial Agents; Calcium Compounds; Chlorhexidine; Ciprofloxacin; Drug Combinations; Follow-Up Studies; Fracture Healing; Humans; Incisor; Male; Metronidazole; Minocycline; Oxides; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Obturation; Silicates; Sodium Hypochlorite; Tooth Fractures; Tooth Root; Young Adult

The present study evaluated the long-term microtensile bond strength of collagen-depleted dentin followed by cyclic loading. Bovine flat, midcoronal dentin received one of the following surface treatments: acid-etch or acid-etched + 5% NaOCl for 2 min. The teeth were restored with Single Bond, Scotchbond Multi-purpose, One-Step Plus, or All-Bond 2 adhesive systems. Half of the specimens were randomly assigned to receive 200,000 cycles (50 N force). Teeth were sectioned into 1 x 1 mm thick slices and stored for 24 h, 1 month, 3 months, or 6 months. Specimens were subjected to tensile testing after elapsed storage time. Samples were analyzed by three-way ANOVA and Fisher's PLSD (p < 0.05). The results showed that the deproteinized groups without cyclic loading presented lower bond strength when compared with the control group, but the difference was only statistically significant for Single Bond and All-Bond 2 (p < 0.05). All adhesives presented a decrease in bond strength over time, regardless of the dentin treatment. When cyclic loaded, the decrease in bond strength for the deproteinized group was even greater when compared with the control group (p < 0.05). The results suggest that the hybrid layer is important as a stress-buffering layer when loading is applied, and thus the presence of collagen is essential.

Topics: Adhesives; Animals; Biocompatible Materials; Cattle; Dental Restoration, Permanent; Dentin; In Vitro Techniques; Microscopy, Electron, Scanning; Oxidants; Sodium Hypochlorite; Stress, Mechanical; Tensile Strength; Tooth Fractures

The purpose of this study was to determine if calcium hydroxide, mineral trioxide aggregate, or sodium hypochlorite caused a change in the force required to fracture root dentin. Ten bovine central and lateral incisors were machined using various saws and drills to produce a cylinder of dentin with a 6.0-mm outer diameter 3.5-mm inner diameter and a length of 10 mm. The cylinders were cut lengthwise into four symmetrical pieces. The canal sides of the sections were then placed into Petri dishes containing a 1-mm depth of calcium hydroxide, mineral trioxide aggregate, sodium hypochlorite, or physiologic saline (control). The samples remained in the dishes for 5 weeks and were then shear tested by using an Instron machine. Data were analyzed using an ANOVA test for comparison of the groups as a whole, and a t test was used to compare each quarter section with its control from the same tooth. A 32% mean decrease in strength was discovered for calcium hydroxide, a 33% decrease in strength for mineral trioxide aggregate, and a 59% decrease for sodium hypochlorite. All decreases in strength were statistically significant: p < 0.001 for calcium hydroxide, p = 0.027 for mineral trioxide aggregate, and p < 0.001 for sodium hypochlorite. Results indicated that root dentin was weakened after 5 weeks of exposure to calcium hydroxide, mineral trioxide aggregate, or sodium hypochlorite.

Topics: Aluminum Compounds; Analysis of Variance; Animals; Calcium Compounds; Calcium Hydroxide; Cattle; Dental Stress Analysis; Dentin; Drug Combinations; Hardness; Hydrogen-Ion Concentration; Oxides; Root Canal Filling Materials; Root Canal Irrigants; Shear Strength; Silicates; Sodium Hypochlorite; Tensile Strength; Tooth Fractures; Tooth Root

Topics: Acid Etching, Dental; Anti-Infective Agents, Local; Child; Chlorhexidine; Composite Resins; Dental Bonding; Dental Cements; Dental Restoration, Permanent; Dentin; Drug Combinations; Female; Glycine; Humans; Incisor; Methacrylates; Resin Cements; Sodium Fluoride; Sodium Hypochlorite; Tooth Fractures