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The aim of this study was to evaluate the deproteinization of primary enamel by analyzing etching pattern types, with and without the application of 5% NaOCl before acid etching with 37% H3PO4. Fifteen extracted human primary molars were randomly selected for the present in vitro study; 1mm x 1mm blocks were prepared and divided into two groups (n = 21). These groups were treated as follows: Group A- Acid Etching with 37% H3PO4 gel for 15 s; Group B- 5% NaOCl for 60 s + Acid Etching with 37% H3POfor 15 s. The specimens were prepared for scanning electron microscopy analysis. The images were evaluated for quality types I and II etching of the enamel surface using ImageJ software. Datasets were checked for normality by Kolgomorv-Smirnov test and the nonparametric unpaired Mann-Whitney test was applied. The mean surface area of type I and II etching pattern values was 1922.314 µm2for Group A and 3840.473 µm2Group B. We conclude that deproteinization with 5% NaOCl prior to acid etching can be used to increase the area of adhesion and the quality of the etching pattern., (Sociedad Argentina de Investigación Odontológica.)

Purpose: To evaluate the influence of enamel condition and etching strategy on bond strength of a universal adhesive in primary teeth., Materials and Methods: Thirty-six primary molars were randomly assigned to six groups (n = 6) according to the enamel condition (sound [S] and demineralized [DEM]/cariogenic challenge by pH cycling prior to restorative procedures) and adhesive system (Scotchbond Universal Adhesive [SBU]) used in either etch-and-rinse (ER) or selfetching (SE) mode, with Clearfil SE Bond as the self-etching control. The adhesives were applied to flat enamel surfaces and composite cylinders (0.72 mm2) were built up. After 24-h storage in water, specimens were subjected to the microshear test. Bond strength (MPa) data were analyzed using two-way ANOVA and Tukey's post-hoc tests (α = 0.05)., Results: Significant differences were found considering the factors adhesive system (p = 0.003) and enamel condition (p = 0.001). Demineralized enamel negatively affected the bond strength, with μSBS values approximately 50% lower than those obtained for sound enamel. SBU performed better in etch-and-rinse mode, and the bond strength found for SBU applied in self-etching mode was similar to that of CSE., Conclusions: Enamel etching with phosphoric acid improves the bond strength of a universal adhesive system to primary enamel. Demineralized primary enamel results in lower bond strength.

Background: To investigate the influence of chemical and microbiological methods of caries induction on bond degradation of adhesive systems to primary dentin., Methods: Flat dentin surfaces from 36 primary molars were assigned to three groups (n = 12) according to method to induce caries-affected dentin: (1) control (sound dentin); (2) pH-cycling; and (3) microbiological caries induction model. Teeth were submitted to caries induction for 14 days for both methods, and the sound dentin was stored in distilled water during the same period. Specimens from each experimental group were then randomly reassigned to two subgroups (n = 6) according to the adhesive system tested: two-step etch-and-rinse adhesive (Adper Single Bond 2 - SB) or two-step self-etch system (Clearfil SE Bond - CSEB). Composite buildups were constructed and sectioned to obtain bonded sticks to be subjected to microtensile (μTBS) testing immediately or after 12 months of water aging. The μTBS means were analyzed by three-way repeated measures ANOVA and Tukey's tests (α = 0.05)., Results: The μTBS values obtained to artificially-created caries-affected dentin were lower compared with sound dentin, but were not affected by method of caries induction. Water storage for 12 months reduced bond strengths, except to CSEB bonded to sound dentin., Conclusion: Chemical and microbiological methods affect similarly the stability of resin-dentin bonds in primary teeth.

Purpose: To investigate the bonding of a new universal adhesive applied using different etching strategies on sound and caries-affected dentin of primary teeth., Materials and Methods: Flat dentin surfaces from 50 primary molars were randomly assigned to 10 groups according to substrate (sound dentin [SD] vs caries-affected dentin [CAD] pH cycled for 14 days) and bonding approach (Scotchbond Universal Adhesive: self-etching, vs dry or wet-bonding etch-and-rinse strategies; Adper Single Bond Plus [two-step etch-and-rinse adhesive] and Clearfil SE Bond [two-step self-etching system] as controls). After 24 h of water storage, bonded sticks with cross-sectional areas of 0.8 mm2 were tested for microtensile bond strength (μTBS). Two sticks from each tooth were immersed in silver nitrate solution in order to evaluate nanoleakage (NL) with SEM. The μTBS means were analyzed using two-way ANOVA and Tukey's tests. For NL, the Kruskal-Wallis and Mann-Whitney tests were used (α = 0.05)., Results: The influence of the etching strategy on the bonding performance of the universal adhesive was substrate dependent. The self-etching approach resulted in lower μTBS values and higher silver nitrate uptake into hybrid layers for Scotchbond Universal Adhesive on SD, while no difference among experimental groups was observed in CAD., Conclusion: It is preferable to use the universal adhesive following either a dry- or wet-bonding etch-and-rinse approach on both sound and caries-affected primary dentin.

Aim: The aim of this study was to evaluate the flexural and μTBS of bulk-fill materials., Study Design: Bulk-fill materials SDR, X-trabase (XTR) and TetricEvoCeramBulkFill (EVO) were used in this study. To test flexural strength, 25x2x2mm samples were prepared and tested with three point bending test. To test the microtensile bond strength (μTBS), two blocks (4x4x4mm) were prepared for each material. In Group A+B, acid-etching was applied to the surface of one of these blocks and no acid-etching was applied in Group B. After applying bonding agent, two blocks were placed into the mold and composite resin (COMP; Tetric N-Ceram) was applied with incremental layering. To evaluate the μTBS of primary dentin, the bulk-fill materials were applied to flat dentin up to 4mm. The new blocks and the teeth were sectioned to obtain sticks and the sticks were loaded in tension until failure. Flexural and microtensile bond strength was calculated based on failure load., Results: The ranking of materials with regards to flexural strength values were SDR>XTR>EVO>COMP,respectively. In GroupA+B, the μTBS values were XTR>SDR>EVO and were XTR>EVO>SDR in GroupB (p>0.05). The μTBS values of these materials to dentin were XTR>EVO>SDR (p>0.05)., Conclusion: Within the limitations of this study, the use of a bonding agent without acid-etching showed positive interactions between base materials and composite resin and there were no significant differences in μTBS of these materials to dentin.

Aim: The aim of this study was to evaluate the effects of a smear layer generated by a high-speed diamond or carbide bur on the durability of microtensile bond strength (μTBS) of a self-etching adhesive to primary dentin., Study Design: Flat occlusal dentin surfaces of 105 human primary molars were exposed using 600 grit silicon carbide paper before being divided into 2 groups for further grinding with either a highspeed diamond or carbide bur. Ten prepared dentin surfaces treated by each bur were evaluated for the characteristics of the smear layer using a scanning electron microscope (SEM). Seventy-five specimens from each bur-prepared group were applied with a 2-step self-etching adhesive (Clearfil SE Bond(®)) then built up with a resin composite. Each bonded specimen was sectioned into a 1-mm thick slab and trimmed to a dumbbell shape with a cross-sectional area of approximately 1 mm(2). All slabs were divided into 3 groups (n=25) according to 3 storage times of 24 hrs, 3 months, and 6 months, in distilled water at 37°C. After storage, the μTBS was determined using a universal testing machine. All fracture specimens were prepared for observation of failure modes. Ten bonded specimens of each bur group were prepared for observation of the resin-dentin interface using an SEM. Smear-layer thickness, μTBS, and failure mode distributions were statistically analyzed., Results: The high speed carbide bur created a significantly thinner smear layer than the diamond bur (p < 0.05). Dentin surfaces treated with a high-speed carbide bur generally obtained significantly higher μTBS than the diamond bur group (p < 0.05). The μTBS gradually decreased over time such that specimens stored for 6 months had significantly lower bond strength than those stored for 24 hrs (p < 0.05). Self-etching adhesive created a hybrid layer of the same thickness when prepared with either a carbide bur or diamond bur, but the carbide bur group had longer and more resin tags., Conclusion: Highspeed carbide bur groups had a higher μTBS than diamond bur groups for all storage times, and bond strengths decreased over time in both substrate groups. The use of a carbide bur produced a thinner smear layer and therefore is recommended when using this 2-step self-etching adhesive to bond the resin composite to primary dentin.

Aim: This study was designed to compare the bond strength of composite resin restorations on the buccal surface of primary human canine after conditioning by conventional acid etching and Er,Cr:YSGG laser., Methods: Twenty sound primary canines were cut buccolingually into two halves and each half was randomly placed in Er,Cr:YSGG laser or acid etch group. The samples in the acid etch group were etched with 37% phosphoric acid for 30 s. The samples in the laser group were prepared by Er,Cr:YSGG laser. The G6-Tips and 600 µm diameter were used with a 1.5 W of power output, pulse duration of 140 µs and repetition rate of 20 Hz. The bonding agent was applied on the buccal surface of each sample and layers of resin composite were placed. The samples' bond strengths were evaluated by a microtensile test instrument., Results: The mean of microtensile bond strength was 18.55±6.41 in the laser group and 24.62±5.56 in acid etch group. Microtensile bond strength achieved by laser conditioning was significantly lower than microtensile bond strength achieved by the conventional acid etching. Statistics To compare the results between the acid etch and laser group, the paired t test was performed (p value<0.001)., Conclusion: Conditioning enamel in primary teeth by Er,Cr:YSGG laser, cannot be used as an alternative method for acid etching and cannot substitute this conventional method.

Purpose: To evaluate the effects of human saliva contamination and two decontamination procedures at different stages of the bonding procedure on the bond strength of two one-step self-etching adhesives to primary and permanent dentin., Materials and Methods: Extracted human primary and permanent molars (210 of each) were ground to mid-coronal dentin. The dentin specimens were randomly divided into 7 groups (n = 15/group/molar type) for each adhesive (Xeno V+ and Scotchbond Universal): no saliva contamination (control); saliva contamination before or after light curing of the adhesives followed by air drying, rinsing with water spray/air drying, or by rinsing with water spray/air drying/reapplication of the adhesives. Resin composite (Filtek Z250) was applied on the treated dentin surfaces. The specimens were stored at 37°C and 100% humidity for 24 h. After storage, shear bond strength (SBS) was measured and data analyzed with nonparametric ANOVA followed by exact Wilcoxon rank sum tests., Results: Xeno V+ generated significantly higher SBS than Scotchbond Universal when no saliva contamination occurred. Saliva contamination reduced SBS of Xeno V+, with the reduction being more pronounced when contamination occurred before light curing than after. In both situations, decontamination involving reapplication of the adhesive restored SBS. Saliva contamination had no significant effect on Scotchbond Universal. There were no differences in SBS between primary and permanent teeth., Conclusion: Rinsing with water and air drying followed by reapplication of the adhesive restored bond strength to saliva-contaminated dentin.

Purpose: To evaluate the effect of cariogenic challenge on the bond strength of adhesive systems to sound and artificially demineralized enamel of primary and permanent teeth., Materials and Methods: Eighty molars (40 primary, 40 permanent) were randomly assigned to 16 groups (n = 5) according to the type of tooth (primary [PRIM] or permanent [PERM]), enamel condition (sound [S] or demineralized [DEM]), treatment after the restorative procedure (control [C] or cariogenic challenge [pH]), and adhesive system (Adper Single Bond [SB] or Clearfil SE Bond [SE]). Teeth from the DEM group were subjected to cariogenic challenge by pH cycling prior to restorative procedures and pH group specimens were subjected to cariogenic challenge before the microshear test. One of two adhesive systems was applied to the flat enamel surfaces and composite cylinders (0.45 mm2) were built. The microshear bond test was performed. The data (MPa) were subjected to ANOVA and Tukey's test (α = 0.05)., Results: No statistically significant differences were detected between the adhesive systems. The S groups exhibited higher bond strength values than the DEM groups, as did C groups compared to pH groups. PERM groups also had higher bond strength values than PRIM groups, excluding PRIM S and PERM S, which had similar values., Conclusion: The bond strength to demineralized enamel of primary teeth was lower than to the demineralized enamel of permanent teeth. Cariogenic challenge negatively influenced enamel bond strength, regardless of the type of tooth and adhesive system.

Purpose: The purpose of this study was to evaluate the influence of prior etching on the sealing of silorane composite restorations in Class V cavity preparations prepared with an Er,Cr:YSGG laser compared to bur preparation in primary teeth., Methods: Standard Class V cavity preparations were prepared on the buccal surfaces of 56 extracted primary canines and randomly divided into four groups of 14 teeth each, according to laser or bur preparation and the use of prior acid etching in the preparation. All cavity preparations were restored with silorane adhesive and silorane composite. After water storage and thermocycling, the specimens were placed in 0.5 percent basic fuchsin dye solution. Dye penetration was evaluated with a stereomicroscope. The data were analyzed with nonparametric tests (P=.05)., Results: Laser preparation and prior etching in bur-prepared cavity preparation had no significant effect on enamel sealing (P>.05), but significantly increased microleakage at the dentin margin (P<.001 and P=.001, respectively). Prior etching in laser-prepared cavity preparations significantly improved sealing at the enamel and dentin margins (P=.009 and P=.003, respectively)., Conclusions: Prior acid etching may be necessary to ensure good marginal sealing when laser preparation is used. However, this step is not required when bur cutting is used in primary teeth.

Purpose: Bioactive glass air abrasion is a conservative technique for removal of initial decalcified enamel superficial layer and caries vs alumina air abrasion. This study evaluated shear bond strength of composite resin to sound and decalcified deciduous enamel using etch-and-rinse and self-etch adhesives after alumina and bioactive glass air abrasion., Materials and Methods: Ninety-six fat enamel surfaces, mounted in acrylic resin, were prepared from 48 deciduous molars. Half of the specimens were decalcified with a demineralizing solution. Both intact and decalcified specimens were assigned to two groups for alumina and bioactive glass air abrasion. In each group, the specimens were subdivided into two groups for application of Clearfil SE Bond or Optibond FL adhesives (n = 12). After composite resin bonding, the specimens underwent shear bond test. Data were analyzed using three-way analysis of variance (ANOVA), linear regression model and independent-sample t-test (α = 0.05)., Results: No significant differences were noted in bond strength of composite resin after alumina or bioactive glass air abrasion (p = 0.272). Optibond FL adhesive and enamel decalcification produced higher bond strength (p = 0.000, p = 0.001 respectively)., Conclusion: In this study, bioactive glass air abrasion produced bond strength comparable to the conventional method. This technique might be an alternative method for preparation of normal and/or decalcified enamel of deciduous teeth for resin bonding.

Purpose: The purpose of this study was to test the hypothesis that the pulp medication ferric sulphate (FS) may remain on primary dentin, affecting its microchemical structure and the bond strength of adhesives to primary dentin., Materials and Methods: The effects of FS and pre-bonding conditioning (37% phosphoric acid [PA] for 15 s or a self-etching primer, with or without the use of 2% chlorhexidine [CHX]) on FS-treated primary dentin were characterized using optical microscopy with Masson's and Perls' stains, variable-pressure SEM/energy-dispersive x-ray spectroscopy (VP-SEM/EDS), Fourier transform infrared spectroscopy (FT-IR), and x-ray diffraction. Ferric sulphate was applied for 30 s or 1 h for microchemical analysis. The adhesive interface and the bond strength were studied by VP-SEM/EDS and the μTBS test (1 mm2 bars, crosshead speed 0.5 mm/min), respectively. The study groups were: etch-and-rinse (E&R, Excite) adhesive (group 1); FS+E&R (group 2); FS+CHX+E&R (group 3); self-etching (SE, Adper Scotchbond) adhesive (group 4); FS+SE (group 5); FS+CHX+SE (group 6)., Results: Ferric sulphate application produced demineralization, gypsum formation, and adsorption of Fe on the dentin surface, and it modified the collagen structure of primary dentin. There were no effects of FS on bond strength of the tested etch-and-rinse adhesive system. FS slightly reduced the bond strength between the primary dentin and the SE adhesive, and the values were not restored by CHX (group 4 = 17.58 ± 5.52 MPa > group 5 = 14.26 ± 7.08 MPa = group 6 = 13.96 ± 4.87 MPa)., Conclusions: Ferric sulphate alters the microchemical structure of primary dentin and can impair the adhesive strength of some self-etching adhesives.

Purpose: The purpose of this study was to examine in vitro the effect of cure mode on the shear bond strength (SBS), failure mode (FM), microleakage (ML), and resin tag penetration (RTP) of two resin composite (RC)/adhesive systems: (1) Clearfil Majesty Esthetic/Clearfil SE Bond (CME/SEB); and (2) TPH 3 Micro Matrix Restorative/Prime&Bond NT (TPH/P&B)., Methods: Paired RC samples (10 CME/SEB; 10 TPH/P&B) were precured or postcured with adhesive on primary molar dentinal substrates and tested for SBS (10 per group); debonded surfaces were examined. Cavities (Class V) in extracted primary molars were restored (20 CME/SEB; 20 TPH/P&B), following precuring or postcuring the adhesive, and examined for ML (eight per group) and RTP (two per group)., Results: Mean SBS (MPa) values differed: precured CME/SEB exceeded postcured CME/SEB (20.16±2.70 versus 10.97±4.39; P<.001), and postcured TPH/P&B exceeded precured TPH/P&B (14.17±3.73 versus 11.10±2.62; P=.007). The FM differed between systems: CME/SEB: precured (four adhesive-dentin; six mixed), postcured (10 adhesive-dentin); TPH/P&B: precured (10 adhesive-dentin), postcured (nine adhesive-dentin; one mixed). Only one specimen showed true ML (postcured TPH/P&B). The RTP was greater in postcured than precured specimens., Conclusion: Precured CME/SEB was deemed superior for restoration of primary teeth, despite extra time required clinically to precure the adhesive.

Objectives: The present study compared the efficacies of the self-etching Teeth Primer (TP: 4-META), and the etchants Red Activator (RA; 65% phosphoric acid) and Green Activator (GA; 10% citric acid with 3% ferric chloride), for bonding to enamel and dentine of human primary and permanent teeth, when used with 4-META/MMA-TBB resin (Bondfill SB)., Methods: Forty-eight non-carious primary canines and third molars were used. Eight groups were prepared: Group 1 (primary enamel with RA), Group 2 (permanent enamel with RA), Group 3 (primary enamel with TP), Group 4 (permanent enamel with TP), Group 5 (primary dentine with GA), Group 6 (permanent dentine with GA), Group 7 (primary dentine with TP) and Group 8 (permanent dentine with TP). Micro-tensile bond strengths (MTBS) were measured and analyzed statistically using ANOVAs and Tukey HSD tests at α=0.05. Efficacy of etching/priming and the morphology of bonded interfaces were observed with SEM., Results: Etching/priming efficacy of TP on enamel was low. The MTBS of Group 2 was significantly higher than the other groups (Groups 1, 3 and 4). For dentine, significant differences in MTBS were observed, in the order of Groups 6>8>7=5 (p<0.05). The MTBSs of permanent dentine were significantly higher than primary dentine. For primary teeth, there was no significant difference in the MTBSs between enamel and dentine, irrespective of primer or etchant (p>0.05)., Conclusion: TP primer/Bondfill SB may be used as an alternative to other adhesive/resin composite systems for bonding to enamel and dentine of primary teeth., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Purpose: To compare the bond strength to human primary dentin of a self-adhesive light-curing resin composite, a self-etch adhesive and a glass-ionomer cement by means of microshear bond strength (pSBS) test and scanning electron microscopic (SEM) observations., Methods: 75 human primary molars were sectioned to obtain a 2 mm-thick slab of mid-coronal dentin, randomly divided into three groups (n=25). Nine conical frustum-shaped buildups were constructed on the occlusal surface of each dentin slab using a self-adhesive light-curing resin composite (Vertise Flow; Group 1), bonding agent (Optibond All-in-One; Group 2) combined with resin composite (Premise Flow) and a glass-ionomer cement (Ketac-Fil; Group 3). After thermocycling, specimens were subjected to microSBS test. All debonded specimens were observed at SEM. Data were analyzed by a mixed model and chi-square test., Results: The bond strength measured in Group 1 (9.0 +/- 4.5 MPa) was significantly lower than that one recorded in Group 2 (20.2 +/-12.5 MPa) although it was significantly higher than the one recorded in Group 3 (4.8 +/- 2.3 MPa). Failures were mainly adhesive in all groups.

Objective: The aim of this study was to evaluate the shear bond strength to dentin of primary molars of a new self-adhering flowable resin composite with two ionomer-based cements and one flowable resin composite in combination with two different adhesive systems., Study Design: Fifty primary molars were grinded on the occlusal surface to obtain flat dentin substrate and randomly divided into 5 groups (n = 10): OFL:Phosphoric Acid/Optibond FL/Premise Flow; OAO:Optibond All-In-One/Premise Flowable; II:Polyacrylic Acid/Fuji II; IX:Polyacrylic Acid/Fuji IX; V:Vertise Flow. Cylinders (3mm diameter - 5mm height) of restorative material were built-up in three increments over the dentin surfaces. A shear load was applied until failure. Bond strength values were statistically analysed with Kruskall-Wallis ANOVA followed by Dunn's test (P < .05). Differences in failure mode distribution were assessed with Chi-square (P < .05)., Results: OFL and OAO recorded significantly higher bond strengths than the other groups. Adhesive failures were evident in all groups except OFL and OAO, in which also cohesive failures in dentin were observed., Conclusions: Vertise Flow established on primary dentin bond strengths values similar to those of glass ionomer cements routinely used for restorations of primary teeth. The combination of flowable resin with etch-and-rinse or all-in-one adhesives obtained higher bond strength values, thus involving a more complex handling.

Aim: The aim of this in vitro study is to evaluate the effects of three different caries removal techniques on the microtensile bond strength of adhesive materials to caries-affected dentin., Materials and Methods: Thirty primary molar teeth were used. The teeth were randomly divided into three groups according to the caries removal technique employed: conventional steel bur (group 1); Er:YAG laser (group 2); chemomechanical method (group 3). Each group was divided into two subgroups according to bonding agents: one-step self-etch adhesive and etch-and-rinse adhesive. The teeth were restored with composite resin. Vertical sticks were obtained and subjected to tensile stress. Data were analyzed by two-way analysis of variance (ANOVA), Tukey's test and an independent samples t-test., Results: The values for the laser groups were significantly lower than those of the bur groups for both bonding agents (p<0.05). There were no significant differences between the bur and chemomechanical groups (p > 0.05)., Conclusion: Bur and chemomechanical techniques in primary teeth were found more successful. Similar results were found according to the adhesives used for each caries removal techniques.

Aim: To compare changes in pulpal chamber temperature during the visible-light curing of direct pulp capping compounds and various modes of diode laser irradiation without prior placement of a pulp capping compound and the resultant seals., Materials and Methods: Pulp exposure holes were made in 100 extracted human primary first molars, which were randomly assigned to ten equal groups. The holes were sealed by (a= Group 1, 2, 3, 4, 5, 6 and 7) different pulp capping compounds which were cured using various types of visible-light curing units or (b=Group 8, 9 and 10) diode laser irradiation without prior application of a pulp capping compound. Pulpal chamber temperatures were recorded during the procedure, and the resultant seals were examined under a scanning electron microscope., Results: Visible-light curing of the pulp capping compounds and diode laser irradiation at a 0.7 W output power can cause non-injurious temperature rises in the pulpal chamber. At higher output powers of the diode laser, the temperature rises are sufficient to cause thermal injury. The seals were complete when pulp capping compounds were used for direct pulp capping, but were incomplete when laser irradiation without prior placement of a pulp capping compound was used for the identical purpose., Conclusion: The visible-light curing of pulp capping compounds is not harmful to vital pulp, and provides an effective seal of the pulp exposure hole. Laser irradiation is not an effective sealant, and can cause thermal injury to vital pulp at high output powers.

Objectives: To determine effect of ageing on deciduous dentine-resin interfaces bond strength and the metalloproteinases (MMPs) activity at the hybrid layer compared to permanent dentine., Methods: Microtensile bond strength (MTBS) tests were performed in human deciduous and permanent dentine after 24h, 3 and 6 months using an etch and rinse adhesive. C-terminal telopeptide concentrations (ICTP) were calculated, in order to determine MMPs mediated collagen degradation at the hybrid layer., Results: The highest MMPs-mediated collagen degradation values occurred in phosphoric acid demineralized dentine, ICTP values were similar for deciduous and permanent dentine after 1 week. Resin infiltration decreased collagen degradation in both dentins and ICTP values were similar to those attained by for untreated dentine. In resin infiltrated and untreated dentine specimens collagen degradation was always higher for deciduous dentine. At 24h, MTBS was higher in permanent dentine. After ageing MTBS decreased and performed similarly in both dentins., Conclusions: Higher collagenollytic activity is found in deciduous than in permanent dentine. At 24h, collagen cleavage by MMPs at the hybrid layer is higher in deciduous dentine leading to a lower MTBS., Clinical Significance: The presence of resin monomers reduced collagen degradation when applied on demineralized dentine, but exerted protection was lower in deciduous dentine., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Purpose: The purpose was to evaluate the effect of acid etching time on the bond strength of a simplified etch-and-rinse adhesive system to noncarious and caries-affected dentin of primary and permanent teeth., Methods: Twenty-four extracted primary and permanent teeth were divided into three groups, according to the acid etching time. Four teeth from each group were exposed to a microbiological caries-inducing protocol. After caries removal, noncarious and caries-affected dentin surfaces were etched with 37 percent phosphoric acid for five, 10, or 15 seconds prior to the application of Prime & Bond NT adhesive. Crowns were restored with resin composite and prepared for microtensile testing. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05)., Results: Higher bond strengths were obtained for noncarious dentin vs. caries-affected dentin for both primary and permanent teeth. Reducing the acid etching time from 15 to five seconds did not affect the bond strength to caries-affected or noncarious dentin in primary teeth. For permanent teeth, lower bond strength values were observed when the noncarious dentin was etched for five seconds, while no difference was seen between 10 and 15 seconds., Conclusions: For Prime & Bond NT, the etching of dentin for five seconds could be recommended for primary teeth, while 10 seconds would be the minimum time for permanent teeth.

Aim: Self-etch bonding systems have been introduced recently and have the advantage of reduced operating time. Because of patient management and isolation difficulties in children, the present study aimed to evaluate microtensile bond strength of two self-etch bonding systems (AdheSE and Xeno® III) on cleaned only, ground and sandblasted enamel., Materials and Methods: Thirty intact primary molars were selected and randomly divided into two groups according to the type of bonding used (Xeno® III and AdheSE). The teeth were divided into three subgroups according to enamel surface conditioning method: prophylaxis with pumice, grinding with coarse finishing and polishing disc, and sandblasting with aluminum oxide particles. Tetric Ceram composite then was applied. Samples were sectioned coronally and axially. The interface area of dental sticks was measured and specimens were subjected to a tensile force of 0.5 mm/min until failure., Results: Microtensile bond strength of Xeno® III-sandblasting, AdheSE-sandblasting, AdheSE-grinding, and AdheSE- cleaned only were 25.5±7.7, 21.2±2.3, 12.9±2.2, and 9.1±1.1, respectively. During sectioning, all specimens of Xeno® III-cleaned only and Xeno® III-grinding groups were fractured., Conclusions: Two step AdheSE yields higher mTBS in comparison to one step Xeno ® III. In regard to surface conditioning, sandblasting increases the mTBS relative to grinding with finishing and polishing disc, and the cleaned-only enamel has the lowest mTBS.

Objective: To compare the effect of the pulpotomy medicaments glutaraldehyde, ferric sulfate, and formocresol on the structure and shear bond strength of a self-etch adhesive to the dentin of primary teeth., Method and Materials: Forty human primary molars were sectioned mesiodistally and divided into four groups: group I (control group), dentin specimens were soaked in distilled water for 48 hours; group II, dentin specimens were soaked in 2% glutaraldehyde; group III, dentin specimens were soaked in formocresol; and group IV, dentin specimens were soaked in 15.5% ferric sulfate. All specimens were rinsed with tap water and dried with air. AdheSE One (a self-etch adhesive) and Valux Plus composite resin were applied to the dentin surfaces. The molecular structure of the adhesive itself and adhesive with composite resin were tested using an FTIR spectrometer. Shear bond strength was tested with a universal testing machine. Failure modes analyses were performed with a scanning electron microscope (SEM)., Results: Glutaraldehyde showed little changes in the molecular structure of the adhesive itself and adhesive with composite. However, ferric sulfate and formocresol affected the molecular structure of the adhesive alone and the adhesive with composite. The highest mean value of shear bond strength was for the glutaraldehyde group (11.17 ± 4.87 MPa). Ferric sulfate and formocresol significantly reduced shear bond strength after the application of pulpotomy medicaments (7.45 ± 3.73 and 5.31 ± 3.30 MPa, respectively). SEM analysis revealed that most of the specimens failed in cohesive and mixed modes., Conclusion: This study revealed that formocresol and ferric sulfate adversely affect the shear bond strength and molecular structure of the adhesive system to primary dentin.

The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate (CHX) on immediate bond strength of etch-and-rinse adhesive to sound (SD) and caries-affected (CAD) primary dentin compared with permanent dentin. Flat dentin surfaces from 20 primary molars (Pri) and 20 permanent molars (Perm) were assigned to 8 experimental groups (n=5) according to tooth type (Pri or Perm), dentin condition (SD or CAD - pH-cycling for 14 days) and treatment (control - C or 60 s application of 2% CHX solution after acid etching - CHX). The bonding system (Adper Single Bond 2) was applied according to manufacturer's instructions followed by resin composite application (Filtek Z250). After 24 h water storage, specimens with cross-section area of 0.8 mm² were prepared for being tested under microtensile test (1 mm/min). Data were submitted to ANOVA and Tukey's post hoc test (α=0.05). Failure mode was evaluated using a stereomicroscope at ×400. Treatment with CHX did not result in higher bond strength values than no pre-treatment (C groups), independently of tooth type. Primary teeth and caries-affected dentin showed significantly lower (p<0.05) bond strength means compared with permanent teeth and sound dentin, respectively. Predominance of adhesive/mixed failure was observed for all groups. CHX did not influence the immediate bond strength to sound or caries-affected dentin of primary and permanent teeth.

This controlled, randomized, in vitro study evaluated the shear bond strength of several seventh generation bonding agents on the dentin of primary teeth. Six different adhesives were used: Xeno IV, Clearfil S3 Bond, Adper Prompt-L-Pop, AdheSE One, Bond Force, and Optibond (control). Ninety primary teeth were prepared by wet grinding with a 320-grit silicon carbide paper on a polishing wheel running at 110 RPM. After 24 hours of storage in water, shear bond strengths of each group were determined. The mean shear bond strength of the tested adhesive systems to primary dentin was 12.27 MPa. One-way ANOVA testing showed a statistically significant difference between adhesive products (P < 0.001). Tukey HSD post hoc tests were used to assess which means were significantly different from one another. There was no statistically significant difference between the fifth generation adhesive system (Optibond) and the two seventh generation systems (Xeno IV and Bond Force), with Optibond exhibiting a lower mean shear bond strength compared to Bond Force. Within the limitations of this study, there is a significant difference between seventh generation bonding materials. Bond Force and Optibond appear to exhibit higher shear bond strengths than the other products.

Purpose: To evaluate the influence of dentin moisture on bond strengths of an etch-and-rinse bonding agent to primary dentin clinically and in the laboratory., Methods: The sample consisted of two groups of 20 caries-free primary second molars: molars in exfoliation period (clinical group) and extracted molars (laboratory group). Class I cavities were prepared in all specimens leaving a flat dentin surface on the pulpal floor. A two-step etch-and-rinse adhesive was vigorously rubbed on either dry (n = 5) or wet demineralized dentin (n = 5) under clinical or laboratory conditions. After restorative procedures, the teeth from the clinical group were extracted after 20 minutes. All samples were processed and underwent microtensile bond strength test and silver nitrate uptake evaluation under scanning electron microscopy., Results: Statistically higher bond strength values were observed when the bonding was performed under laboratory conditions and on a wet demineralized dentin. Most of the failures were adhesive and mixed irrespective of the experimental condition. Silver nitrate uptake occurred in all groups irrespective of the experimental condition. Resin-dentin bond strengths produced in the laboratory in primary teeth may overestimate those produced under clinical circumstances.

Objective: The purpose of this study was to compare the immediate microtensile bond strength (microTBS) of two-step etch-and-rinse adhesive systems to the dentin of primary and permanent teeth., Study Design: Non-carious human teeth (12 primary molars and 12 premolars) were assigned to 3 groups according to the adhesive system. The adhesive systems were applied to flat superficial coronal dentin surfaces etched with phosphoric acid and composite resin blocks were built up. The teeth were sectioned to produce beam-shaped specimens with 0.81 mm2 cross-sectional area subjected to microTBS testing. MicroTBS data were analyzed statistically by ANOVA and Tukey's test (a = 0.05)., Results: The adhesive systems produced statistically similar mean microTBS to each other (p > 0.05) and no significant differences (p > 0.05) were found when the same material was applied to primary or permanent tooth dentin. The mean microTBS values (MPa) obtained were: Prime & Bond NT: 41.7 +/- 14.4 (permanent) and 40.8 +/- 13.4 (primary); Single Bond: 42.9 +/- 8.6 (permanent) and 41.4 +/- 11.9 (primary); Excite DSC: 46.3 +/- 11.3 (permanent teeth) and 43.4 +/- 12.0 (primary)., Conclusion: There was no difference in the immediate microTBS of two-step etch-and-rinse adhesive systems when applied to the dentin of primary and permanent teeth.

The aim of this in vitro study was to evaluate the tensile bond strength of a self-etching adhesive system to three different dentinal substrates. Primary molar teeth that had been recently exfoliated (RE), with unknown time of exfoliation (UT), and extracted due to prolonged retention (PR) were used for this investigation. Ten primary molar teeth of each group were cut in the middle following the mesio-distal direction, creating a total of twenty specimens per group. The specimens were included in acrylic resin and had a flat dentin surface exposed. The self-etching adhesive system was applied to this surface and a 3-millimeter high cone with diameter of 2 mm in the adhesion area was constructed using composite resin. The specimens were stored in distilled water at 37ºC for 24 hours. Fifteen specimens of each substrate were used for the tensile bond test (n = 15) and 5 had the interface analyzed by scanning electron microscopy (SEM). The data was examined by one-way ANOVA and presented no significant differences between groups (p = 0.5787). The mean values obtained for RE, UT and PR were 18.39 ± 9.70, 19.41 ± 7.80, and 23.30 ± 9.37 MPa, respectively. Any dentinal substrates of primary teeth studied are safe for tensile bond strength tests with adhesive systems.

Purpose: The purposes of this study were to: (1) examine the shear bond strengths (SBSs) of orthodontic brackets bonded to primary teeth with conventional, self-etching, and moisture-insensitive primers; and (2) evaluate the mode of bracket failure., Methods: Seventy-eight human primary teeth were divided equally into 6 groups: (1) the enamel surface was etched, and a conventional primer was applied under dry conditions; (2) the enamel surface was dried, and a self-etching primer was applied; (3) the enamel surface was etched, and a moisture-insensitive primer was applied under dry conditions; (4-6) the same adhesives were used as those in groups 1 to 3, but before priming, each tooth was moistened. Metal brackets were bonded with adhesive. SBSs were measured using a universal testing machine, and the bracket/adhesive failure modes were evaluated with the adhesive remnant index., Results: A notable drop in bond strength and a high incidence of bond failure at the enamel-adhesive interface were found in group 4. There was no significant difference in mean SBSs among the other groups., Conclusion: These adhesive systems under specific conditions enable us to use a primary tooth in the sectional bracket appliance as the anchor tooth, thus helping improve the outcome of early treatment for malocclusion.

Purpose: To examine the ultrastructure and silver nanoleakage of the resin-dentin interfaces in sound and caries-affected primary tooth dentin bonded with a 4-META one-step self-etch adhesive., Methods: Each of five sound and carious primary molars was bonded with Hybrid Bond. Resin-dentin interfaces were observed with TEM micrographs obtained from silver-impregnated, unstained and undemineralized sections of bonded sound and caries-affected primary dentin, and stained and demineralized sections of bonded sound and caries affected primary dentin without silver impregnation., Results: For sound dentin, silver nanoleakage was observed extensively in the patent dentin tubules, within the dentin beneath the hybrid layer, within the hybrid layer in some specimens, and as water trees that partially protruded into the overlying adhesive layer. The hybrid layer was about 1 microm thick. Smear plugs in the dentin tubules and smear on the ground dentin protruded in the hybrid layer. Remnants of demineralized smear were observed overlying the adhesive layer. For caries-affected dentin, the hybrid layer was obscure. Dentin tubules were occluded with mineral deposits. There were no water trees or nanoleakage in the adhesive layer or hybrid layer. However, smear remnants were observed in the adhesive layer and large silver deposits were observed in the highly porous underlying caries-affected dentin.

Objectives: This in vitro study compared the bonding performance of four adhesive luting agents to dentin and enamel of human and bovine primary teeth, in order to evaluate the suitability of primary bovine hard tissues for replacement of those of human origin for bond testing., Methods: A composite (Clearfil AP-X) was bonded to specimens from 167 extracted human (n=88) and bovine (n=88) primary teeth using the following adhesive systems: Syntac Assortment (SY), Adaper Prompt L-Pop (PLP), iBond Gluma inside (IB) and Clearfil Protect Bond (PB). After 24h storage in distilled water, shear bond strength was determined according to ISO/TS 11405:2003. The data (n=11 per group) were statistically analyzed with the Mann-Whitney U-test and the error-rates method (ERM). The fracture modes were analyzed with the chi2-test., Results: Bond strength data (ERM) and fracture modes (chi2-test) using human primary teeth were, in general, not statistically different from those of bovine origin. With few exceptions, pair wise comparisons showed the same results. The bond strength data for SY, PLP and PB bonded to primary human and bovine enamel were higher than those to primary human and bovine dentin, for IB vice versa., Significance: Bovine teeth may be considered as a suitable alternative to human teeth in bond strength tests for primary dentition.

Purpose: To assess in vitro the shear bond strength at the resin/dentin interface in primary teeth after contamination with fresh human blood., Methods: 75 crowns of primary molars were embedded in acrylic resin and mechanically ground to expose a flat dentin surface. The specimens were randomly assigned to five groups (n=15), according to the surface treatment. Group 1 (control) had no blood contamination. The other groups were blood-contaminated and subjected to different post-contamination protocols: in Group 2, the surfaces were rinsed with water; in Group 3, the surfaces were air-dried; in Group 4, the surfaces were rinsed and air-dried; and in Group 5, no post-contamination treatment was done. In all groups, a 3-mm dentin bonding site was demarcated, Single Bond adhesive system was applied and resin composite cylinders were bonded. After 24 hours in distilled water, shear bond strength was tested at a crosshead speed of 0.5 mm/minute., Results: Means (in MPa) were: Group 1: 7.1 (+/- 4.2); Group 2: 4.0 (+/- 1.8); Group 3: 0.9 (+/- 0.7); Group 4: 3.9 (+/- 2.2) and Group 5: 1.3 (+/- 1.5). Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. Groups 2 and 4 were similar to each other (P > 0.05) and both ware similar to Group 1 (P > 0.05). These groups (2, 3 and 4) had statistically significantly higher bond strengths than Groups 3 and 5 (P < 0.05). Blood contamination negatively affected the shear bond strength to primary tooth dentin. Among the blood-contaminated groups, water-rinsed specimens had higher bond strengths than those that were exclusively air-dried or not submitted to any post-contamination protocol before adhesive application.

Purpose: This study compared the effectiveness of self-etch and total-etch adhesive systems in bonding to the beveled and nonbeveled margins of primary and permanent teeth., Methods: This in vitro, factorial-designed study allowed evaluation of 3 factors: (1) tooth type; (2) presence of a bevel; and (3) adhesive type. Two preparations, each including a beveled and nonbeveled margin, were completed on buccal surfaces of 60 extracted molars (30 primary and 30 permanent). Preparations were randomly assigned to self-etch or a total-etch adhesive system and restored with resin composite. After thermocycling, teeth were stained with silver nitrate, sectioned, and measured for microleakage. Statistical analysis used a repeated measures analysis of variance., Results: Beveled margins had less microleakage than nonbeveled margins for primary and permanent teeth (P < .001). Total-etch had less microleakage than self-etch adhesives on primary (53% less, P < .001) and on permanent teeth (22% less, P = .01). Self-etch had considerably more microleakage when enamel margins were not beveled. Comparably less microleakage, however, was found for total-etch and self-etch in restorations with beveled margins., Conclusions: Total-etch adhesive and beveled margins resulted in the least microleakage. Margin beveling has a greater effect in minimizing microleakage than the type of adhesive used.

Aim: As bond strength of currently available adhesive systems in caries-affected teeth dentin on primary tooth dentin was not well known, the bond strength of two bonding systems (PQI and OptiBond Solo Plus) was evaluated on caries-affected and sound primary molar tooth dentin and observed the micromorphology of the adhesive-dentin interfaces., Methods: By grinding both the sound (n = 30) and caries-affected (n = 30) approximal surfaces of teeth, flat dentin surfaces were obtained. The prepared surfaces were bonded with one of the each adhesive systems and a composite resin. After storing the bonded specimens in water at 37 degrees C for 24 h, the samples were sectioned and the bond strength of the adhesive systems was tested by the microshear test method. The data were statistically analysed., Results: Microshear bond strengths of PQI group for caries-affected and sound primary tooth dentin were 9.43 +/- 2.44 (MPa) and 9.32 +/- 2.95 (MPa) (P > 0.05), respectively, and the bond strengths of OptiBond Solo Plus group for caries-affected and sound primary tooth dentin were 15.33 +/- 3.59 (MPa) and 11.96 +/- 2.30 (MPa) (P < 0.05), respectively. Micromorphological features between sound and caries-affected dentin were similar in both PQI and OptiBond Solo Plus groups., Conclusion: Both the adhesives showed significantly different bond strengths in caries-affected dentin but showed similar bond strengths in sound dentin.

This in vitro study sought to evaluate the bond strength and interfacial morphology of composite restorations in primary and permanent teeth that utilized different adhesive systems. In this study, 180 samples (n = 15 per subgroup) were submitted to shear bond strength tests while 72 samples were analyzed with scanning electron microscopy (n = 6 per subgroup). Fifty-four blocks of permanent enamel, 54 blocks of permanent dentin, 54 blocks of primary enamel, and 54 blocks of primary dentin were randomly assigned to three groups for bonding. All of the blocks received a resin composite restoration made with a matrix after the application of the dental bonding systems, according to the manufacturer's instructions. The shear bond strength test found no statistical differences among the tissues or the adhesive systems used. However, a difference in quality of the interfacial seal was observed when Single Bond restorations were compared to restorations bonded with AdheSE and Prompt-L-Pop. The Single Bond system formed an authentic hybrid layer that can ensure adequate adhesion. The other adhesive systems showed an interface with inadequate sealing and even with no sealing. The self-etching systems must be used with caution in composite restorations because the quality of the hybrid layer formed is as important as the bond strength when determining the efficacy of the adhesive.

Purpose: Laser pretreatment of dental hard tissues prior to preventive or restorative procedures has been a subject of research. Unground primary enamel bears a prismless superficial layer which is known to be acid resistant. This in vitro study was conducted in order to evaluate the potential use of Er,Cr:YSGG laser in the pretreatment of occlusal surfaces of primary teeth prior to bonded fissure sealant application., Materials and Methods: Occlusal surfaces of human primary mandibular molars were used (n =140). After pretreatment with Er,Cr:YSGG laser (group A) or not (group B), occlusal fissures were treated with one of the following in each of 7 subgroups (n = 10): 1. phosphoric acid-etch only; 2. Clearfil SE Bond; 3. FL Bond; 4. Adper Prompt L-Pop; 5. NRC+Prime & Bond NT; 6. One-Up Bond F; 7. Xeno III. All teeth were sealed with Fissurit F. The specimens were thermocycled (1000 times) and stored thereafter in distilled water at 37 degrees C for 8 months. Following immersion in 0.5% basic fuchsin solution, three bucco-lingual sections were made from each tooth. They were digitally photographed and the extent of dye penetration along the enamel-sealant interface was measured (in mm) with image analysis software., Results: There was no difference between the Er,Cr:YSGG laser pretreated group (group A) and the nonlased grou (group B) (p > 0.05). The lowest microleakage values were observed in subgroups A1 and B1. Within the laser pretreated group, subgroups A1, A4, and A5 showed lower microleakage scores when compared to subgroups A2, A3, A6, and A7 (p < 0.05). As for the nonlased group, subgroups B1, B3, B4, and B5 demonstrated significantly lower microleakage scores than subgroups B2, B6, and B7 (p < 0.05)., Conclusion: Er,Cr:YSGG laser pretreatment was not found to influence the resistance to microleakage of bonded fissure sealant application in primary teeth.

Purpose: Fatigue resistance of post and cores is critical to the long term behavior of restored nonvital teeth. The purpose of this in vitro trial was to evaluate the influence of the post material's physical properties on the adaptation of adhesive post and core restorations after cyclic mechanical loading., Materials and Methods: Composite post and cores were made on endodontically treated deciduous bovine teeth using 3 anisotropic posts (made of carbon, quartz, or quartz-and-carbon fibers) and 3 isotropic posts (zirconium, stainless steel, titanium). Specimens were submitted to 3 successive loading phases--250,000 cycles at 50 N, 250,000 at 75 N, and 500,000 at 100 N--at a rate of 1.5 Hz. Restoration adaptation was evaluated under SEM, before and during loading (margins) and after test completion (margins and internal interfaces). Six additional samples were fabricated for the characterization of interface micromorphology using confocal microscopy., Results: Mechanical loading increased the proportion of marginal gaps in all groups; carbon fiber posts presented the lowest final gap proportion (7.11%) compared to other stiffer metal-ceramic or softer fiber posts (11.0% to 19.1%). For internal adaptation, proportions of debonding between dentin and core or cement varied from 21.69% (carbon post) to 47.37% (stainless steel post). Debonding at the post-cement interface occurred only with isotropic materials. Confocal microscopy observation revealed that gaps were generally associated with an incomplete hybrid layer and reduced resin tags., Conclusion: Regardless of their rigidity, metal and ceramic isotropic posts proved less effective than fiber posts at stabilizing the post and core structure in the absence of the ferrule effect, due to the development of more interfacial defects with either composite or dentin.

Currently, there is little information regarding the bonding efficacy of single-step self-etch systems to primary tooth dentin. This study examined the microtensile bond strength of single-step self-etch systems (Clearfil tri-S Bond and One-Up Bond F Plus) to sound primary and permanent tooth dentin. Adhesives were applied to flat samples of primary and permanent tooth dentin, and resin composites were bonded according to the manufacturers' instructions. After 24 hours of storage in distilled water at 37 degrees C, hour glass-shaped specimens were produced. They were subjected to microtensile testing at a crosshead speed of 1.0 mm/minute. The results were analyzed using 2-way analysis of variance (ANOVA) followed by the Tukey HSD post-hoc test (alpha=0.05). Field-emission scanning electron microscopy (FE-SEM) observations of the adhesive-treated dentin surfaces and the resin/dentin interface were also conducted. The bond strengths of primary tooth dentin were significantly lower than that of permanent tooth dentin for both self-etch systems: 44.7 +/- 10.4 versus 54.3 +/- 9.0 MPa for Clearfil tri-S Bond and 40.6 +/- 9.9 versus 50.0 +/- 8.7 MPa for One-Up Bond F Plus (p<0.001). There was no statistically significant interaction between the type of adhesive system and the dentin substrate (p=0.957). Although there was no statistically significant difference in the mean values among the different adhesive systems (p=0.094), there was a statistically significant difference in mean values among the different dentin substrates (p<0.001), which were lower for primary tooth dentin than for permanent tooth dentin. The failure modes were also independent of the type of dentin but dependent on the adhesive systems, an equal distribution among the 3 types of failure for Clearfil tri-S Bond and cohesive failures in adhesives for One-Up Bond F Plus. FE-SEM observations of dentin to which adhesive had been applied revealed that the smear layer had been removed and the collagen fibers exposed. Though the bond strengths to primary tooth dentin were lower than to permanent tooth dentin, excellent adaptation of the single-step self-etch systems to both dentin substrates was observed by FE-SEM. Further studies are required to determine the long-term clinical performance of these adhesive systems when applied to primary tooth dentin.

The aims of this study were to evaluate the shear bond strength (SBS) off our adhesive systenms applied to primary dentin and enamel and verify, after SBS testing, the failure mode of the adhesive interface. Sixty extracted sound primary molars were selected and crowns were sectioned in a mesial-distal direction. Specimens were randomly assigned into two groups (adhesion to enamel and adhesion to dentin) and then subdivided into four subgroups according to the adhesive system (n=15). Scotchbond Multi-Purpose (SMP)--Single Bond (SB)--Clearfil SE Bond (and Adper Prompt L-Pop (APL)--SBS tests were performed and the obtained values were statistically analyzed using ANOVA and Tukey tests (p < 0.05). The failure mode analysis was performed with a Scanning Electron Microscope (XL-30, Philips). SBS mean values on enamel were [MPa (SD)]: SMP--2789 (749); SB--23.92 (8.8); CSB--24.36 (6.69), APL--25.96 (4.08); and on dentin: SMP--17.29 (4.25) SB--18.2 (8.74); CSB--16.13 (714); APL--6. 04 (3.35). The predominant failure mode was cohesive (primarily of the bonding agent). On enamel SBS was statistically similar for all four adhesives. On dentin SBS ofAPL was lower than the other tested adhesives.

Purpose: To investigate the effects of saliva contamination on the bond strengths of two compomers applied to primary teeth dentin during different bonding stages., Methods: 30 extracted human non-carious primary molars were prepared for shear bond-strength testing. Specimens were randomly divided into three groups of 10. Prime & Bond NT (acetone-based) and Futura Bond A & B (water-based) adhesives were tested under the following conditions: (a) non-contaminated conditions; (b) after contamination of the dentin surface with fresh whole saliva for 20 seconds and removal of excess saliva before adhesive application; and (c) contamination of the dentin surface with fresh whole saliva for 20 seconds and removal of excess saliva after adhesive curing. Following adhesive application Dyract AP or Glasiosite was applied via a polytetrafluroethylene split mould and light-cured to the dentin surface. Shear bond strengths were measured using an Instron Universal testing machine running at a crosshead speed of 1 mm/minute. After measuring shear bond strengths, specimens were prepared for SEM evaluation and identification of failure type. Results were analyzed by two-factor experiment with repeated measures as one factor., Results: No statistically significant differences were found among the shear bond strengths (P > 0.05) of the groups. The results revealed that saliva contamination of dentin surfaces before or after adhesive application did not affect the shear bond strength of either compomer.

Background: The objec tives of this study were to determine microtensile bond strengths of two dentin adhesives and to compare the micromorphological structure of the resin/dentin interface in caries-affected dentin with that of intact dentin., Methods: The authors randomly divided 40 proximal dentinal carious primary teeth and 40 noncarious anterior primary teeth into two groups (self-etching and total-etching). They used a caries-detecting dye as an indicator of the need to remove the outer carious dentin. The authors restored the teeth with a hybrid resin-based composite. After 24 hours' storage in 37 C water, specimens were sectioned and shaped to form a curved section with a cross-sectional area of 1 square millimeter, then tension was applied until they fractured. The authors prepared the resin/dentin interfaces for the two bonding systems and examined them in 10 occlusal carious and 10 noncarious teeth., Statistical Analysis: The bond strengths for intact and caries-affected dentin within the same group were analyzed via a t test. The authors compared the remaining dentin thickness (RDT) and dentin hardness using analysis of variance and the least significant difference test at the .05 level of significance., Results: The self-etching adhesive demonstrated no statistical difference in bond strength between intact and caries-affected dentin. However, the total-etching adhesive demonstrated different bond strengths for intact and caries-affected dentin. Moreover, the RDT of specimens with intact and caries-affected dentin was not significantly different, whereas the dentin hardness of caries-affected dentin was significantly lower than that of intact dentin. The authors found a thicker hybrid layer in intact and caries-affected dentin of specimens in the total-etching group., Conclusion: The adhesives exhibited significantly different bond strengths in intact dentin of primary teeth. However, they exhibited similar bond strengths in caries-affected dentin.

Objective: This study evaluated the influence of Carisolv (Medi Team) for resin adhesion to sound human primary and young permanent dentin., Methods: The buccal surfaces of 28 primary molars and 64 premolars were used. Two adhesive systems and resin composites were used; SE: Clearfil SE (Kuraray) and Clearfil APX (Kuraray), and SB: Single Bond (3M) and Z250 (3M). Six groups were prepared. Groups 1-2 were primary dentin and Groups 3-6 were permanent dentin. Groups 1 and 3: SE was used. Groups 2 and 4: treated with Carisolv and then primed, SE was used. Group 5: SB was used. Group 6: treated with Carisolv and then etched, SB was used. The microstructural effects of primer or etchant, and Carisolv plus primer or etchant applied to dentin were evaluated by SEM. In addition, the microstructure of the resin-dentin interfaces of each group was studied using SEM. Shear bond strengths (SBS) were tested, and the failed surfaces were observed using SEM. Data was statistically analyzed using ANOVA with subsequent application of Fisher's PLSD at p<0.05., Results: The mean SBS (unit: MPa) of Groups 1-6 were: 27.8, 19.2, 21.3, 21.7, 6.7 and 7.6. The SBS of Group 2 was significantly lower than that of Group 1. There was no significant difference of the SBS among Groups 1 and 4, 2, 3 and 4, and 5 and 6. In SE groups, the hybrid layer for primary dentin was thicker than that for permanent dentin., Conclusions: Carisolv treatment before priming significantly decreased the SBS to primary dentin in SE groups, but did not influence the SBS to permanent dentin in both SE and SB groups.

The aim of this study was to evaluate the micro-tensile bond strength of adhesive systems (OptiBond Solo, Kerr; Prime & Bond NT, Dentsply) on occlusal surface of primary molars. The adhesives were tested under manufacturers' specifications and after contamination of the bonding site with saliva. Hourglass cylindrical-shaped samples were obtained and subjected to a tensile force. No significant difference was observed among the groups. OptiBond Solo and Prime & Bond NT showed similar values of bond strengths when applied on occlusal enamel of primary molar under either saliva contamination or not.

Purpose: The objective of this study was to compare the effect of phosphoric acid and a self-etching adhesive on the short and long-term bond strength of a light-curing sealant to unground primary and permanent enamel., Methods: A light-curing resin sealant (Delton Light Curing Pit & Fissure Sealant-CLEAR) was bonded to the flattest, peripheral surface of 40 primary and 40 permanent molars following conditioning of the cleaned enamel with 38% phosphoric acid or with the self-etching adhesive Prompt L-Pop (N=10/group). After either 1 week or 1 year in water, shear bond strengths were measured. Failure mode was determined in a stereo microscope., Results: There was no significant difference in bond strengths between the phosphoric acid-etch and the self-etching adhesive groups, nor between the 1-week and 1-year results (P>.05). However, the bond strengths to primary enamel were lower than those to permanent enamel (P=.0021). The number of pure adhesive failures in each of the 8 groups varied between 0 and 3 (0-30%), and the remaining teeth displayed mixed adhesive-cohesive failures., Conclusions: The self-etching adhesive studied seems an attractive alternative to the acid-etch technique for sealant application in young children where simplifications in the clinical procedure are warranted.

Purpose: This study measured the microtensile bond strengths of 2 tooth-colored restorative materials with and without conditioning of primary teeth dentin, and examined the micromorphology of the debonded surfaces and material-dentin interfaces., Methods: Cylindrical specimens of packable composite resin (PCR) and resin-modified glass ionomer cement (RMGIC) bonded to dentin of primary teeth were ground to an hourglass shape and tested for microtensile bond strength. The debonded surfaces and material-dentin interfaces were prepared and examined under a scanning electron microscope (SEM)., Results: The microtensile bond strength values (mean +/- SD, in MPa) of PCR (Filtek P60 with Single Bond) and RMGIC (Fuji II LC), with or without the application of Cavity Conditioner (14.8 +/- 5.36, 12.01 +/- 4.43, 11.94 +/- 4.60, respectively), did not differ significantly (P > .05). Partial adhesive and partial cohesive failures within the restorative material predominated. The distributions of failure modes did not differ significantly between groups (P > .05). Under SEM, each material was seen to be closely adapted to dentin. Dentinal tubules were enlarged with etching, and the depth of penetration of resin tags of PCR was greater than for RMGIC. Smear plugs were incompletely removed by cavity conditioning., Conclusions: The bond strength of the PCR, Filtek P60 with Single Bond, to dentin of primary teeth was comparable to that of the RMGIC, Fuji II LC. Conditioning of the cavity preparation with Cavity Conditioner did not improve the bond strength of Fuji II LC. The distribution of failure modes did not differ between materials.

Purpose: To evaluate the bond strengths of three polyacid-modified resin composites and one resin-modified glass-ionomer cement to caries-simulated primary dentin after 18-months' water immersion., Methods: Dyract AP, Compoglass F, F2000 and Vitremer were used as test materials. Standardized preparations cavities with a C-factor of 5 were prepared in primary molars. Half of the cavities were stored in a demineralizing media for 7 days to simulate caries-affected dentin. Thereafter, all preparations were restored with the test materials, after which the specimens were stored in water for 18 months, changing the water every week. The specimens were subjected to a microtensile test and all bond strength data (in MPa) were statistically analyzed using one-way analysis of variance (ANOVA) and Tukey HSD tests at P < 0.01., Results: The mean microtensile bond strength to normal primary dentin specimens were 11.2 +/- 1.5 (Dyract AP), 10.6 +/- 2.1 (Compoglass F), 10.8 +/- 1.1 (F2000) and 7.3 +/- 1.6 (Vitremer), while those to the caries-simulated dentin were 4.1 +/- 0.7 (Dyract AP), 3.0 +/- 0.6 (Compoglass F), 2.3 +/- 0.9 (F2000) and 1.9 +/- 0.5 (Vitremer). SEM evaluation of the unfractured specimens revealed evidence of gap formation in the adhesive interface in all samples.

Purpose: The purpose of this in vitro study was to determine the shear bond strengths (SBS) of Non-Rinse Conditioner (NRC, Dentsply) combined with Prime & Bond NT (PBNT, Dentsply), a 1-bottle adhesive. The null hypothesis tested was that the use of NRC with PBNT would not result in SBS different from those obtained with conventional phosphoric acid (PA) etching and bonding application to permanent and primary dentin., Methods: Extracted human third molars and primary molars were mounted length-wise in acrylic resin. The occlusal surfaces were ground to expose a flat dentin surface, and then polished to 600 grit silicon carbide paper to create smear layers similar to those created with high-speed burs. The teeth were randomly assigned to 4 groups (N = 10) according to the etchant/conditioner (PA vs NRC) and dentin (permanent vs primary) used: (Group I: permanent dentin, PA, PBNT; Group II: primary dentin, PA, PBNT; Group III: permanent dentin, NRC, PBNT; Group IV: primary dentin, NRC, PBNT). Specimens were then secured in a split mold, having a 5 mm diameter opening and a polyacid-modified resin composite (Dyract AP, Dentsply) were inserted and light cured incrementally onto the treated dentin surfaces. All specimens were stored in water for 24 hours prior to shear strength testing using a Franell testing machine at a crosshead speed of 0.8 mm/minute., Results: The mean dentin SBS values (MPa) for the groups were: Group I (13.32 +/- 6.6); Group II (15.21 +/- 5.25); Group III (8.87 +/- 3.12); and Group IV (7.42 +/- 2.98). Analysis of variance and Duncan's multiple range tests indicated significant differences among groups at P < 0.05., Conclusions: In general, the SBS were remarkably greater in the 2 groups etched with PA in comparison with the 2 groups conditioned with NRC. However, the type of dentin tissue did not influence SBS.

Direction of dentin tubules is an important factor that affects bond strength of contemporary adhesive materials. Because conservative proximal cavity preparations in primary teeth contain more dentin tubules running oblique or parallel to the cavity walls, this study was conducted to evaluate the influence of tubule orientation on the bond strength to primary dentin. A polyacid-modified resin composite material was used as the test material. A microtensile test was utilized to enable evaluation of bond strengths in three different tubule orientations (perpendicular, oblique, parallel) following aging of the resindentin bonds by long-term immersion of the test samples in water. Samples bonded parallel to the dentin tubules showed the highest microtensile bond strength, followed by the oblique and perpendicular groups. Statistical analysis of the data showed no significant difference between the bond strength of parallel and oblique groups. Independent of the tubule orientation, all samples revealed cohesive fracture within dentin.

Purpose: The aim of this study was to determine the effect on shear bond strength of chlorhexidine used as a cavity disinfectant on primary tooth dentin., Methods: Thirty specimens were randomly divided into 3 groups (N = 10) and treated as follows: (1) in Group I, the dentin was acid etched with a 37% phosphoric acid for 15 seconds, washed and dried; (2) in Group II, a 2% commercial chlorhexidine solution (Cav Clean) was applied for 40 seconds, washed and dried following acid etching for 15 seconds; and (3) in Group III, dentin was treated with a 37% phosphoric acid gel containing 2% digluconate of chlorhexidine (Cond AC) for 15 seconds. In all specimens, the adhesive Single Bond (3M) was applied, and composite cylinders (Filtek Z 250) were built. The specimens were sheared with a universal testing machine (Instron) running at a crosshead speed of 0.5 mm/min, and the results calculated in MPa. The specimens were also observed to record the failure mode., Results: ANOVA analysis revealed that the shear bond strength of Group II (17.99+1.15 MPa) was significantly lower than Group I (19.88+1.02 MPa) and Group III (19.57+1.02 MPa). After debonding, 63% of the specimens presented cohesive failure of the material, 24% adhesive failure and 10% cohesive failure of dentin., Conclusions: The commercial cavity disinfectant containing 2% chlorhexidine had an adverse effect on Single Bond and produced significantly lower shear bond strength than the etch gel with chlorhexidine and the acid etch alone.

The bonding performance of current adhesive systems to primary enamel has not been thoroughly researched. This study compared the micro-shear bond strength of two adhesive systems to primary and permanent tooth enamel. Two commercially available resin adhesives, a self-etching primer system (Clearfil SE Bond) and a single-bottle adhesive system (Single Bond) used with a total-etch wet bonding technique were tested. A micro-shear bond test was used to examine the adhesive systems on mid-coronal buccal enamel of extracted primary or permanent teeth. In addition, etched enamel surfaces and etched-bonded enamel interfaces were examined using scanning electron microscopy (SEM). No statistically significant differences of shear bond strength values were found between the primary and permanent enamel or the adhesive systems used (p>0.01). The SEM observations showed that both adhesive systems etched the primary enamel deeper than the permanent enamel, suggesting that the action of acid etch seemed to be more intense on primary enamel than on permanent enamel. Bonding of the adhesive systems to primary enamel was almost identical to permanent enamel.

Objectives: Limited information exists with regard to the adhesive ability of glass ionomer cements (GIC) and recently developed resin-based dentin bond systems to primary dentin. The aim of this study was to compare the microtensile bond strength of a conventional GIC (Fuji IX), a resin-modified GIC (Fuji II LC), and two resin-based dentin adhesives (Prime and Bond NT with NRC and Single Bond). The bonded interfaces were also observed using field emission electron microscopy(FE-SEM)., Methods: Microtensile bond test specimens were prepared on superficial dentin of primary and permanent molars. The specimens were bonded according to each manufacturer's instructions except for Prime and Bond NT/NRC which used Silux Plus resin composite instead of Dyract. Hour-glass shaped specimens were created (diameter of 1.2+/-0.02 mm) and stressed in tension at a crosshead speed of 1mm/min. Results were analyzed using two-way ANOVA and LSD test, fracture modes were analyzed using the Mann-Whitney U-test and Kruskall-Wallis test. Twelve specimens were prepared for each material on primary and permanent dentin. Samples were prepared in the same manner, then critical point dried, fractured and sputter-coated for the FE-SEM observations., Results: Two-way ANOVA showed the overall bond strengths were greater for the permanent dentin compared with primary dentin. However, for individual material comparisons no differences among the bond strengths to primary and permanent dentin for Fuji IX (9.7, 12.2 MPa), Fuji II LC (16, 20.1 MPa), Prime & Bond NT/NRC (18.1, 21.6 MPa) and Single Bond (18.2, 21.6 MPa), were detected. However, Fuji IX bond strengths were significantly lower than the other systems tested when bonded to either primary or permanent dentin (p<0.05). Failure mode showed cohesive failure of GIC and mostly adhesive failure for the resin-based adhesives. The FE-SEM observations showed hybrid-like layer formation for the GIC materials and hybrid layer formation for the resin-based adhesives., Significance: The materials tested would be suitable for bonding to either primary or permanent dentin, but the resin-modified GIC or resin-based systems are likely to provide a stronger bond than the conventional GIC, Fuji IX.