maleic-acid and Smear-Layer

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

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

The use of disinfectants on the dentin surface contributes to superficial cleaning and removal of remaining microorganisms of the carious process. However, the effect of these agents on the adhesion of resin materials to the dentin surface of primary teeth has not been established. This study evaluated the dentin micromorphological effects due to the use of antimicrobial agents in the different depths of dentin. Twenty-five buccal surfaces of primary molars were prepared from the sectioned teeth, ground flat and polished with silicon carbide paper of different grits. The surfaces were treated with 32% phosphoric acid with benzalkonium chloride (Bisco), 35% phosphoric acid gel (3 M), 3% benzalkonium chloride solution by itself or 10% maleic acid. All agents were applied for 15 seconds on the dentin surface. The samples were washed with distilled water, dried and coated with gold for observation of the dentin surface with the scanning electron microscope. The samples were subdivided according to the dentin depth in upper, middle and lower areas. The following was observed: presence of smear layer, opening of the dentin tubules, and inter and intratubular dentin morphology. The effects of the antimicrobial agents were compared in the different depths of the dentin. The results demonstrated that the surface conditioned with 3% benzalkonium chloride solution presented few disclosed dentin tubules. The use of the 32% phosphoric acid with benzalkonium chloride completely removed the smear layer and increased the diameter of the dentin tubule openings. The 35% phosphoric acid totally exposed the tubules in the upper area of the analyzed surface but partially exposed them in the middle and lower areas. The 10% maleic acid totally removed the smear layer, left all the tubules opened and conditioned the intertubular dentin. It was concluded that in the different depths of the dentin surface, conditioning with 10% maleic acid in primary teeth showed the most consistent micromorphological characteristics compared to the other agents used in this study.

Topics: Acid Etching, Dental; Anti-Infective Agents, Local; Benzalkonium Compounds; Carbon Compounds, Inorganic; Child; Dental Bonding; Dental Polishing; Dentin; Humans; Maleates; Microscopy, Electron, Scanning; Microtomy; Phosphoric Acids; Resins, Synthetic; Silicon Compounds; Smear Layer; Surface-Active Agents; Tooth, Deciduous

Topics: Ceramics; Citric Acid; Dental Pulp Cavity; Edetic Acid; Humans; Microscopy, Confocal; Root Canal Filling Materials; Smear Layer

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

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 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

To compare the effect of QMix (Dentsply Sirona), 7% maleic acid (MA), and 17% ethylenediaminetetraacetic acid (EDTA) on the microhardness, flexural strength and microstructure of mineral trioxide aggregate (MTA; ProRoot MTA, Dentsply Sirona).. Forty MTA specimens were divided into four groups: [I] QMix [II] 7% MA [III] 17% EDTA and [IV] distilled water (control). After treatment with 5mL of the respective solution for 1min, the specimens were tested for microhardness using a Knoop hardness tester. Forty additional specimens were similarly treated and evaluated for the flexural strength using a universal testing machine. For microstructure evaluation, MTA specimens were treated in a similar manner and examined by X-ray diffractometry and scanning electron microscopy (SEM).. For microhardness, there were no differences between distilled water, QMix and EDTA groups. However, MTA exposed to distilled water had higher microhardness than MA. When compared with QMix and EDTA, MA had lower microhardness; there was no difference between EDTA and QMix. For flexural strength, distilled water group had higher flexural strength than the other agents. There were no differences between EDTA vs MA and EDTA vs QMix. Specimens treated with QMix had higher flexural strength than MA. X-ray diffraction indicated that EDTA inhibited hydration of MTA. For SEM, all the tested agents altered the microstructure of MTA when compared to distilled water.. MA had more detrimental effect on the physical properties of MTA and EDTA was more detrimental to the hydration of MTA.. The present study highlights the effect of newer chelating agents on the physical properties and microstructure of MTA. Preventing the deterioration of MTA is important for its long term success in endodontic procedures.

Topics: Aluminum Compounds; Biguanides; Calcium Compounds; Compressive Strength; Dental Cements; Drug Combinations; Edetic Acid; Hardness; Hardness Tests; Maleates; Materials Testing; Oxides; Polymers; Root Canal Filling Materials; Root Canal Irrigants; Silicates; Smear Layer; Stress, Mechanical; Surface Properties; Water; X-Ray Diffraction

To evaluate the effect of maleic acid (MA) on the cleaning efficacy and mechanical properties of root canal dentine with respect to different time exposure.. One hundred and eighty single-canal premolars were instrumented with rotary-files and then randomly assigned to test groups receiving 7% MA for 30 s, 45 s, 1 min, or 3 min or to control groups treated with 0.9% saline or 17% ethylenediaminetetraacetic acid for 45 s. The micro-hardness, nano-hardness and elastic modules were measured before and after treatment, while the amount of smear and erosion in the coronal, middle and apical thirds in root canal were evaluated by scanning electron microscopy, finally, the fracture strength was assessed by vertical root fracture testing.. The efficacy of smear layer removal increased with increasing MA application time. The largest effect was observed at 45 s, even in the apical third, whereas the treatment for 1 min resulted in irreversible erosion of the dentine surface. The micro-hardness and nano-indentation testing confirmed that the micro- and nano-scale mechanical properties were significantly decreased after MA application for 1 min. Furthermore, the specimens treated with MA for 3 min presented the lowest fracture resistance among all groups. In contrast, the 45 s treatment appeared to increase the fracture resistance of the tooth.. The cleaning efficacy and mechanical properties of root canal dentine varied with MA exposure time. The application of MA for 45 s was found to be the most promising for clinical use.

Topics: Bicuspid; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Edetic Acid; Elastic Modulus; Hardness; Humans; Maleates; Materials Testing; Microscopy, Electron, Scanning; Random Allocation; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Stress, Mechanical; Time Factors; Tooth Apex

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

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 evaluated the ultra-morphological effects of maleic and citric acid on human dentin by means of a field emission in-lens scanning electron microscope (FEISEM). Both acids were tested on human dentin at pH 0.7 and 1.4 in aqueous solutions.. Each of 12 dentin disks were divided into four groups and exposed to either maleic acid at pH 0.7, maleic acid at pH 1.4, citric acid at pH 0.7 and citric acid at pH 1.4. All samples were then fixed and dehydrated in a critical point drying apparatus. Observations were carried out by means of a FEISEM (JEOL 890) after coating with a carbon-platinum film.. Both acids removed smear layer and partially removed smear plugs. Details of fine structures measuring from 5 to 15 nm were shown on the intertubular demineralized dentin. Maleic acid at pH 0.7 showed the highest depth of demineralization of all the tested samples; citric acid, showed a higher depth of demineralization values when tested at pH 1.4 than at pH 0.7.. The FEISEM reveals ultra-structural aspects of the demineralization process of the dentin tissue of the both acids tested. Differences related to the pH of the acids were found. Images obtained at high magnification clarify the dentin collagen structure of both peritubular and intertubular dentin. Small periodic structures associated with collagen fibrils were also imagined.

Topics: Acid Etching, Dental; Analysis of Variance; Carbon; Citric Acid; Collagen; Dentin; Humans; Hydrogen-Ion Concentration; Maleates; Microscopy, Electron, Scanning; Minerals; Platinum; Smear Layer; Statistics, Nonparametric

In an attempt to compare the morphology of the resin-dentin interface in areas where the dentinal tubules run perpendicularly or at an angle to the cavity surface with that of areas where they run parallel to it, we studied a dentin adhesive system using transmission electron microscopy and fluorescence confocal laser scanning microscopy. The design of the study included the simulation of the normal hydrostatic pressure within the pulp and the dentinal tubules. Following acid etching of the dentinal surface with maleic acid/HEMA, the smear layer was removed, and a superficial zone was demineralized in such a way that the exposed collagenous dentin matrix retained its integrity. Confocal laser scanning microscopal investigations using primer labeled with rhodamine B showed that the penetration of the primer occurred not only vertically via surface porosities, but mainly laterally, via the dentinal tubules. The adhesive resin labeled with fluorescein completely infiltrated the demineralized layer, thereby forming a hybrid layer. The orientation of the dentinal tubules had a profound effect on the formation of the hybrid layer. In areas with perpendicular tubule orientation, the layer was 3.2 +/- 0.8 microns thick, showing solid 27.2 +/- 0.8 microns long resin tags in the dentinal tubules, and a network of tiny tags in their side-branches. In areas with parallel tubule orientation the layer was significantly thinner (1.3 +/- 0.6 microns) and resin tags were absent.

Topics: Acid Etching, Dental; Adhesives; Collagen; Dental Bonding; Dental Cavity Preparation; Dental Pulp; Dentin; Dentin-Bonding Agents; Fluorescein; Fluorescent Dyes; Humans; Hydrostatic Pressure; Maleates; Methacrylates; Microscopy, Confocal; Microscopy, Electron; Microscopy, Fluorescence; Porosity; Resin Cements; Rhodamines; Smear Layer; Surface Properties

The aim of the study was to evaluate the effect of some acidic conditioners on dentin morphology, molecular composition and collagen conformation in situ.. Smear layer-covered dentin specimens prepared from third molars immediately after extraction were imaged by tapping made AFM and analyzed by MIR-FTIR spectroscopy. The same specimens were subjected to conditioning treatments with CA Agent (Kuraray), Scotchbond Etchant (3M Dental Products) and Scotchbond MP Etchant (3M Dental Products) gels and then imaged and analyzed again. The extent of dentin decalcification at the uppermost 2 microns region was calculated from the percentage reduction in the-PO4/amide I peak area ratio of conditioned specimens relative to their individual smear layer-covered references. These results were compared by ANOVA and Scheffé statistical analyses. The conformational changes of dentin type I collagen at the region were studied qualitatively by deconvoluting the amide I bands of MIR-FTIR spectra and assigning the band components to carbonyl hydrogen bonding states related to the alpha-helix structure.. All the conditioners removed the smear layer, funneled the tubules, increased the intertubular roughness and contaminated the dentin surfaces with residues from irreversibly adsorbed thickening agents. Conditioned dentin surfaces showed a reduction in orthophosphates and carbonates and an increase in amide I, II and III groups. CA Agent manifested a significantly lower extent of dentin decalcification than Scotchbond etchants (p < 0.05). Collagen conformational changes involved a decrease in intermolecular hydrogen bonded amide I carbonyls associated with the alpha-helix structure and enhancement of imide carbonyls hydrogen bonded to water, which suggest collagen denaturation.. Apart from dentin decalcification, the acidic conditioners induced considerable changes on dentin collagen conformation mostly associated with denaturation processes. In addition, irreversibly adsorbed residual thickeners substantially modified the morphology and composition of dentin surfaces. These findings show the complex interaction pathways between conditioners and dentin surfaces and the great potential of modern in situ imaging and analysis techniques in probing these interactions.

Topics: Acid Etching, Dental; Amides; Analysis of Variance; Citric Acid; Collagen; Dentin; Hydrogen-Ion Concentration; Maleates; Phosphoric Acids; Protein Conformation; Regression Analysis; Smear Layer; Spectroscopy, Fourier Transform Infrared; Surface Properties; Tooth Demineralization

The aim of this in vitro study was to evaluate, using scanning electron microscopy (SEM), the effects of acid solutions on dentin surface, and to analyze the depth of demineralization that the acid solutions cause on dentin, using different acids. Fifteen 3-mm thick dentin discs were prepared from the middle third of human molars. Standard smear layer was prepared on the dentin surface using 600 grit sandpaper, for 1 minute. The acids used were 10%, 35% and 37.5% phosphoric acid and 10% maleic acid, for 15 seconds, washed and dried. The control group received no treatment. Dentin discs were fractured, observed on the horizontal surface and also on the fractured surface to evaluate the depth of demineralization. Specimens were immersed in 4% glutaraldehyde in phosphonate buffer, and prepared for SEM examination at 2000X and 4000X magnification. Acid etching of dentin, regardless of the concentration of phosphoric acid, caused removal of the smear layer, exposing the apertures of dentinal tubules. This was not observed when 10% maleic acid was used. At the fractured surface, one could observe an increase in demineralization of the width of dentinal tubules, to a specific depth of about 8.19 to 11 mm, except for 10% maleic acid.

Topics: Acid Etching, Dental; Dentin; Humans; In Vitro Techniques; Maleates; Microscopy, Electron, Scanning; Osmolar Concentration; Phosphoric Acids; Smear Layer; Surface Properties

The shear bond strengths of a dental bonding system used in conjunction with a composite resin bonded to dentin were determined 1 minute after irradiation and after storage in saline at 37 degrees C for 24 hours, 1 week without and with temperature cycling, and 4 weeks without and with temperature cycling. The quantitative microleakage of class V preparations in cementum (dentin) restored with the system was determined by a spectrophotometric dye-recovery method. Excellent shear bond strengths ranging from 13.9 MPa (1 minute) to 19.5 MPa (1 week) were obtained. The shear bond strengths and quantitative microleakage of the multipurpose dental adhesive system compared favorably with the data obtained from other dental bonding systems under similar experimental conditions.

Topics: Analysis of Variance; Dental Bonding; Dental Leakage; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Humans; Least-Squares Analysis; Maleates; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Resin Cements; Smear Layer; Tensile Strength; Wettability

Since dentin permeability ultimately affects bond strength, the purpose of this study was to compare the effects of different concentrations of maleic acid, and different exposure times on dentin permeability.. One hundred and thirty freshly extracted human non-carious third molars were used. Hydraulic conductance was determined after various treatments. The teeth were divided into five groups. In the first group, the smear layer was untreated. In three other groups, 0.10, 0.25, or 0.5 M aqueous solution of maleic acid was applied on dentin slices for 15, 30, or 60 s. In the last group, the Scotchbond Multi-Purpose dental adhesive system (3M Dental Products) conditioner was applied for 15, 30, or 60 s.. After a 60 s exposure time, the Scotchbond Multi-Purpose dentin conditioner or the 0.1 M solution of maleic acid was as effective at increasing dentin permeability as the 0.25 M and 0.5 M maleic acid solutions. The maximum dentin permeability was reached after 15 s with 0.25 M and 0.5 M solutions of maleic acid, after 30 s with Scotchbond Multi-Purpose and after 60 s with the 0.1 M solution of maleic acid. During the first 30 s, the 0.1 M solution of malic acid did not increase dentin permeability and did not completely remove the smear layer; a SEM examination of the dentin slices corroborated the functional results.. The manufacturer's recommendation of 15 s of etching using Scotchbond Multi-Purpose conditioning gel produced a moderate amount of etching which increases dentin permeability to about one-half its maximum value.

Topics: Acid Etching, Dental; Analysis of Variance; Dentin; Dentin Permeability; Dentin-Bonding Agents; Dose-Response Relationship, Drug; Gels; Humans; Hydrostatic Pressure; Maleates; Microscopy, Electron, Scanning; Resin Cements; Smear Layer; Time Factors

Nine noncarious human molars were extracted and stored in saline solution. Three standard occlusal cavities with beveled enamel margins were prepared on each tooth and etched with the etching solutions of three dentinal adhesive systems: (1) 37% phosphoric acid solution, (2) 4.3% oxalic acid and 2.6% aluminum salts solution, and (3) 10% maleic acid solution. Scanning electron microscopic analysis revealed that all the etching solutions affected the enamel surface morphology. The solution of oxalic acid and aluminum salts removed primarily the prism core material and partially the periphery of the prisms, but did not affect the nonbeveled enamel surface. Phosphoric and maleic acids removed both prism core materials and prism periphery; these specimens also showed areas in which no prism morphology could be detected. These two acids also removed apatite crystals from the prism core of the intact enamel surface.

Topics: Acid Etching, Dental; Dental Enamel; Dentin; Humans; Maleates; Microscopy, Electron, Scanning; Molar; Oxalates; Oxalic Acid; Phosphoric Acids; Smear Layer

Recently many researchers have become interested in the adhesion of composite resin to the dentinal surface. Because it is easier to obtain good composite resin adhesion when a surface is free from smear plug, several chemical agents (acids or linking agents) have been suggested for surface preparation. Nevertheless, the pretreatment of dentin leads to an increase of pulpal outflow, which can interfere with the bonding agent's adhesion. Thus, new-generation dentinal bonding agents appeared on the market. They use a pool of highly absorbent primers to facilitate the scattering of the agent in the dentin substratum under humid conditions. The present study shows the results, obtained with the help of scanning electron microscopy, of resinous penetration into the tubular structures of dentin using a latest-generation bonding system. The in vivo and in vitro tests showed a deep scattering of intermediate fluid resin into tubules, even in the presence of physiologic outflow of dentinal fluids.

Topics: Acid Etching, Dental; Bisphenol A-Glycidyl Methacrylate; Composite Resins; Dental Bonding; Dentin; Dentin-Bonding Agents; Humans; Maleates; Materials Testing; Microscopy, Electron, Scanning; Resin Cements; Smear Layer; Surface Properties

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

The purpose of this study was to compare the structure of acid-conditioned dentin in its wet and dry state.. Using conventional and environmental scanning electron microscopy, conditioned dentin was examined in a wet, air-dried and critical point-dried state. Six different treatments were used including citric, maleic, nitric, oxalic and phosphoric acids in their commercial formulations and applied in accordance with manufacturer's instructions.. Loss of moisture from acid-conditioned dentin through simple air drying and drying under controlled conditions of environmental scanning microscopy resulted in morphological alteration of the fibrous, collagenous structure. Critical point drying preserved the fibrous integrity of the outer mineral-depleted zone. This observation was true for all the acids used.. While the ultrastructure of dentinal collagen may be chemically stabilized or relatively unaltered by acid conditioning, it is nonetheless subject to morphological degradation and collapse during water loss. Only critical point drying can control the interfacial stress accompanying water transport and loss at the fiber boundary. Confirming previous observations, this study supports the concept of maintaining the moist state of dentin and the morphological integrity of the collagen so as to facilitate optimal resin infiltration in the bonding procedure.

Topics: Acid Etching, Dental; Citrates; Citric Acid; Collagen; Dental Bonding; Dentin; Dentin Permeability; Desiccation; Maleates; Microscopy, Electron, Scanning; Nitric Acid; Oxalates; Oxalic Acid; Phosphoric Acids; Smear Layer; Surface Properties; Water

This study used scanning electron microscopy (SEM) to evaluate the effects of various acid conditioners (etchants) on dentine surfaces. The conditioners completely removed the smear layer from dentine and opened the dentinal tubules, but some also left debris or a reaction product on the surface. The study also evaluated the resin-dentine interfaces produced by five new-generation dentine bonding systems: All-Bond 2, Amalgambond, Gluma 2000, OptiBond, and Scotchbond Multi-Purpose. All-Bond 2, Amalgambond, OptiBond, and Scotchbond Multi-Purpose formed acid-resistant hybrid layers and intra-tubular resin tags when they were applied to visibly moist dentine.

Topics: Acid Etching, Dental; Adhesives; Aluminum Compounds; Bisphenol A-Glycidyl Methacrylate; Chlorides; Citrates; Citric Acid; Composite Resins; Dentin; Dentin-Bonding Agents; Ferric Compounds; Glutaral; Humans; Maleates; Methacrylates; Microscopy, Electron, Scanning; Nitrates; Oxalates; Oxalic Acid; Phosphoric Acids; Polymethacrylic Acids; Resin Cements; Smear Layer; Surface Properties

Research into polymer systems capable of bonding to dentin and enamel have resulted in improved bond strengths that allow more conservative restoration and strengthening of teeth. However, pretreatment of the dentin and enamel of various sorts, including exposure to laser energy, have been espoused to enhance this bonding. This study investigated the effects of two pretreatments, acid and CO2 laser exposure, both alone and in combination, on the surface topography of prepared dentin specimens as observed by scanning electron microscopy. Eighteen dentin specimens were flat-sanded with 600 grit sandpaper and exposed to 10% maleic acid and CO2 laser both alone and in combination. SEM observation suggested that laser treatment prior to acid etching could increase the resistance of the smear layer to acid removal, that laser exposure after acid treatment could expose a porous topography suggestive of the underlying dentin inorganic structure by way of vaporization of the collagen surface left after acid demineralization, and that these effects varied in degree with the laser exposure energy.

Topics: Acid Etching, Dental; Dentin; Humans; In Vitro Techniques; Lasers; Maleates; Microscopy, Electron, Scanning; Molar; Smear Layer

The aim of the present study was to evaluate the surface morphology and the permeability of dentine after different acid treatments: polyacrylic acid, maleic acid, phosphoric acid and saline solution as control. Dentine permeability was expressed as hydraulic conductance. All the acid treatments removed the smear layer and increased the dentine permeability.

Topics: Acid Etching, Dental; Acids; Acrylic Resins; Adult; Dental Cavity Lining; Dentin Permeability; Humans; Maleates; Microscopy, Electron, Scanning; Phosphoric Acids; Smear Layer