Single Bond 2 Research Articles

Comparison of bond strength of a composite resin with two different adhesive systems and a resin modified glass ionomer to calcium enriched mixture.

Context:It is necessary to have a proper bond between pulp-capping agent and composite materials to maintain effective coronal seal.Aims:This study aims to compare the shear bond strength of a composite resin with two different adhesive systems and a resin-modified glass ionomer (RMGI) to calcium-enriched mixture (CEM).Methods:In this study, 30 acrylic blocks (with a central hole 4 mm diameter and 2 mm height) were prepared and filled with CEM. The blocks were divided into three groups: single bond2 (SB) with Filtek Z250, single bond universal (SBU) with Filtek Z250, and RMGI. The restorative materials were placed on the CEM, and shear bond strength was measured. Data were analyzed using one-way ANOVA and games Howell tests. P < 0.05 was considered statistically significant.Result:Bond strength of both composite groups to CEM showed significantly higher values than RMGI-CEM group (both P < 0.001). The type of the adhesive system( total etch or universal) had no significant effect on the bond strength of composite to CEM (P > 0.05). All the failures in composite groups were as cohesive in CEM and in RMGI group was as adhesive.Conclusions:Shear bond strength of composite resin to CEM cement was higher than RMGI irrespective of the type of the adhesive system. The universal bonding system is recommended for bonding of composite to CEM for ease of use.

PERBANDINGAN KEBOCORAN MIKRO PADA RESTORASI KOMPOSIT DENGAN PEMAKAIAN BONDING GENERASI KELIMA DAN BONDING GENERASI KETUJUH

Composite resin is the most frequently material used for restoring teeth but still failure cases are seen which leading to microleakage. Microleakage might be attributed to various factors, one of them is bonding agent. Various generations of bonding agents have been introduced to overcome the microleakage. The aim of this study was to evaluate the microleakage of composite restorations using the fifth and seventh bonding agent. Class I cavities (3X2X2 mm) were prepared on the occlusal surfaces of 32 human upper premolars. Teeth were classified into two groups according to the type of bonding agent used (n =16). Group I: Fifth Generation of Bonding Agent-Adper Single Bond2. Group II: Seventh Generation of Bonding Agent-Single Bond Universal. All cavities were restored with Filtek Z250 XT composite resin, stored in sterile aquades water at 370C for 24 h. The root apices were sealed with sticky wax, and all the surfaces, except for 2 mm from the margins, were coated with nail varnish. The teeth were immersed in a 1% methylene blue dye solution for 24 h, and then rinsed in running water, blot-dried and sectioned longitudinally through the center of restorations from the buccal to palatal surface. The sections were blindly assessed for microleakage of dye penetration by using a stereomicroscope. Data were collected and statistically analyzed by independent t -test. There was no significant difference (p&gt;0,05) between two groups. The conclusion is fifth generation of bonding agent revealed less leakage compared to the seventh generation even statistically there was no significant difference.&#x0D; Keywords:Microleakage, fifth generation of bonding agent, seventh generation of bonding agent.

SHEAR BOND STRENGTH OF UNIVERSAL-ADHESIVE TO DIFFERENT FIXED PROSTHODONTIC MATERIALS

Objectives: To evaluate the shear bond strength (SBS) of Universal adhesive (Single Bond Universal SBU), that contain silane and MDP adhesive molecules, to different fixed prosthodontic materials (High-Leucite ceramics, Zirconia ceramics and base metal alloys).Methods: Twenty high-leucite based ceramics IPS Empress (Ivoclar) and twenty Ni-cr alloys Remanium-CSe(Dentaurum) specimens were constructed in discs of 5mm diameter and 3mm thickness. Twenty Zirconia based ceramics INcoris-TZI (Sirona) specimens were prepared of 19X15X3mm blocks. All specimens were embedded into acrylic resin blocks of 2x2X2cm. Composite discs 3mm in diameter Z-350(3M ESPE) were prepared and bonded to each material, divided into 2 groups according to the bonding procedures (N=10). High-Leucite ceramics etched with 5%HF acid then for Group1 composite discs were bonded with Single Bond2 SB2 and RelyX ultimate resin-cement RXU, after Silane Si application (Si+SB2+RXU), for Group 2 composite discs were bonded with Single Bond Universal adhesive and RelyX Ultimate without separate Silane application (SBU+RXU). Metal and zirconia specimens were air abraded 50µm AL2O3 then for Group 1; composite discs were bonded with Panavia cement only (Pa). For Group 2, composite discs were bonded with Single Bond Universal and RelyX Ultimate (SBU+RXU). All the specimens were thermo-cycled in water baths 5-55°C for 5000 cycles. The SBS was tested in a universal testing machine (Tira) using a chisel-edge blade. The results were statistically analyzed using Mann-Whitney test.Results: bThe mean (SBS±SD) in MPa were: In high leucite ceramics (23.1±2.5), (23.6± 1.9) for (Si+SB2+RUX) and (SBU+RUX) respectively. In Zirconia ceramics: (7.96± 3.1) and (16.8± 5.4) for (Pa) and (SBU+RXU) respectively. In Base metal alloys: (14.8±5.4) and (20.9±2.7) for (Pa) and (SBU+ RXU) respectively. Statistical analysis using Mann-Whitney test showed no significant difference for the high leucite and base metal groups (P>0.05) while there was significant difference for the zirconia groups (P<0.05). Conclusion: The Universal-adhesive SBU produced bond strength to high leucite-ceramics comparable to that of resin cement with separate Silane application. It produced higher bond strength to zirconia ceramics and base metal alloys in comparison to Panavia adhesive-resin cement.

SHEAR BOND STRENGTH OF DIFFERENT ADHESIVE RESIN CEMENTS TO DENTIN

Objective: This study investigated the shear bond strength SBS of different adhesive resin cements [self-adhesive resin cement RelyX Unicem(RXU), adhesive resin cement with self-etch adhesive RelyX Ultimate with Single bond Universal adhesive (RXUT) and adhesive resin cement that utilize etch and rinse technique RelyX ARC with Single bond2 adhesive (ARC)] to dentin. Methods: Sixty extracted molars embedded in epoxy resin were prepared by sectioning the buccal surface to expose flat Buccal dentin and were ground with 400-grit SiC paper. The samples were divided into 3 groups (N=20) based on the adhesive resin cements used. Sixty composite discs 3mm in diameter Z 350 (3M ESPE)) were constructed & bonded to the prepared dentin surfaces according to manufacturer instructions. For each group half the samples were thermo-cycled (TC) between 5-55˚C for 2500 cycles and then all samples were tested using a universal testing machine using chisel blade. The results were statistically analyzed using Mann-Whitney &Wilcoxon Signed Ranks tests.Results: The mean SBS (± standard deviation) were: 6.95±1.5 MPa for RXU, 0 for RXU(TC), 22.58±5.45 for RXUT, 15.20±3.98 for RXUT (TC), 25.9±5.3 for ARC, and 19.5±4.3 for ARC(TC). RXU had significant lower bond strength than both RXUT &ARC (P 0.05).Conclusions: (1) The self-adhesive resin cement (RXU) had significant lower bond strength to dentin than that of RXUT & ARC. (2) No significant difference was found between the used adhesive resin cements that utilized self-etch adhesive and that utilized etch & rinse adhesive.

Effects of Epigallocatechin-3-gallate (EGCG) on the bond strength of fiber posts to Sodium hypochlorite (NaOCl) treated intraradicular dentin

This study was to evaluate the effect of Epigallocatechin-3-gallate (EGCG) on the bond strength of two adhesive systems to the Sodium hypochlorite (NaOCl) treated intraradicular dentin. The roots were accepted regular root canal treatments and post space preparations, and further divided into eight groups according to the four post space pretreatments and two dentin adhesives [Single Bond 2 (SB2) and Clearfil SE Bond (CSB)] used. The push-out strength before and after thermocycling in different root region (coronal and apical), DC of the adhesive and morphologic patterns of treated post space were evaluated. NaOCl + EGCG groups showed the highest push-out strength regardless of the adhesive type, root region and time (P < 0.05). NaOCl pretreatment significantly decreased the push-out strengths and DC of CSB (P < 0.05). EGCG could improve the bonding properties of both SB2 and CSB to NaOCl treated intraradicular dentin. The effect of NaOCl on bonding of a fiber post depended on the type of the adhesive.

Effects of epigallocatechin-3-gallate modification on the bonding stability of an etch-and-rinse adhesive to intraradicular dentin

Objective: To evaluate the effects of epigallocatechin-3-gallate (EGCG) modification on the bonding stability of an etch-and-rinse adhesive to intraradicular dentin, and to find a new strategy to improve the stability of bonding interface. Methods: EGCG was incorporated into Single Bond 2 (SB2) with the concentration of 200 mg/L and 400 mg/L respectively to fabricated experimental adhesives group A and group B, while Single Bond 2 without EGCG was used as control group. Laser scanning confocal microscope (LSCM) and scanning electron microscope (SEM) were used to observe the bacterial biofilm adherent to the surface of the cured adhesive. Micro-Raman spectrum was used to test the degree of conversion (DC) of adhesives. The push-out bond strength of instant testing and aging with thermocycling for 5 000 times were also tested. Results: Group A and group B showed inhibiting effect on the biofilm formation of Enterococcus faecalis and performed better with higher concentration. No significant differences were detected in DC among group A ([69.73±0.68]%), group B ([69.03±1.65]%) and control group ([70.06±1.62]%) (P>0.05), and the immediate push-out bond strength of control group ([10.45±2.00] MPa) was not compromised compared to group A ([10.02±2.03] MPa) and group B ([9.95±3.03] MPa) (P>0.05). After thermocycling for 5 000 times, group A ([7.01±1.39] MPa) and group B ([7.62±1.88] MPa) showed significantly higher push-out bond strength than control group did ([5.08±1.56] MPa) (P<0.05). Conclusions: EGCG modified etch-and-rinse adhesives showed anti-bacterial effect and enhanced bonding stability of intraradicular dentin-adhesive interfaces.

Effect of different gutta-percha solvents on the microtensile bond strength of various adhesive systems to pulp chamber dentin.

The aim of this study was to evaluate the effect of different endodontic solvents on the microtensile bond strength (μTBS) of various adhesives to pulp chamber dentin. A total of 120 human third molars were selected. Canals were prepared with the ProTaper Universal system and obturated. The access cavities were then restored with resin composite. After 1week, a retreatment procedure was applied as follows: control, no solvent was applied to the pulp chamber and experimental groups, three different solvents (chloroform, eucalyptol, and orange oil) were applied to the pulp chamber for 2min. The canal filling was removed and calcium hydroxide (Ca[OH]2) was placed into the canals. After 7days, the Ca(OH)2 was removed from the canals and the canals were re-obturated. Teeth were then divided into three subgroups according to the adhesive used. The samples were restored with a nanohybrid resin composite using three different adhesives: Clearfil SE Bond (CSE), Adper Easy One (AEO), and Single Bond 2 (SB2). The samples were aged with thermocycling. Teeth were sectioned, and a total of 20 dentin sticks were obtained for each subgroup. μTBS testing was then performed. The debonded surfaces were evaluated using scanning electron microscopy (SEM) analysis. Data were analyzed using two-way ANOVA and Tukey's post hoc tests. Chloroform showed statistically lower mean μTBS values (14±7.2MPa) than control group did (19.2±6.1MPa) (p<0.05). Orange oil (18.1±6.3MPa) and eucalyptol (16.9±6.8MPa) did not reduce the mean μTBS statistically (p>0.05). Chloroform showed significantly lower bond strength for all adhesives (p<0.05). Whereas orange oil did not reduce the mean μTBS values of all adhesive systems significantly (p>0.05), eucalyptol reduced the μTBS values of all the groups, but the results were only statistically significant for SB2 (p<0.05). CSE showed statistically higher bond strength (20.4±6.8MPa) than AEO (14.6±5.3MPa) and SB2 (16.3±7.2MPa) did (p<0.05). There were no statistical differences between AEO and SB2 (p>0.05). According to the SEM analysis of the debonded surfaces, adhesive failures were the most common type in all the groups, followed by mixed failures. While chloroform reduced the mean bond strength of the adhesive resins, orange oil did not affect the bond strength of the adhesives. The effect of eucalyptol on bond strength depended on the type of adhesive system. This study shows that endodontic solvents could affect the microtensile bond strength of adhesives to pulp chamber dentin.

Correlation between bond strength and nanomechanical properties of adhesive interface.

The aims of this study were to evaluate the nanohardness and Young's modulus of the adhesive-dentin interface and to correlate them with the microtensile bond strength (μTBS) after storage in water for 24h and 6 months. Eighty human third molar teeth were bonded to composite resin with the Adper Scotchbond Multipurpose (SBMP), Adper Single Bond 2 (SB2), Clearfil SE Bond (CSE) or Clearfil S3 Bond (CS3) adhesive systems and stored in water for 24h and 6months. Three bonded teeth were selected for each group for nanoindentation methodology to obtain the nanohardness and modulus values (n=3), while seven bonded teeth each group were used for μTBS (n=7). Data were analyzed by two-way ANOVA and Tukey's test (α=0.05). Spearman correlation between nanohardness and modulus and μTBS values was also calculated. Nanohardness and Young's modulus values for the dentin and hybrid layer were not significantly different regardless of the adhesive system or water storage periods (p>0.05). Nanohardness and Young's modulus values for the adhesive layer were significantly higher for SB2 than for SBMP, CSE, and CS3 systems in both water storage periods. The μTBS values for SBMP and CSE were significantly higher than for SB2 and CS3 in both storage periods. An inverse correlation between Young's modulus and μTBS was observed for the adhesive layer. The water storage periods did not alter nanohardness, Young's modulus, and μTBS of adhesives. The adhesive layer of SB2 showed the highest nanohardness and Young's modulus, but the highest dentin bond strength was obtained with SBMP and CSE. Thus, a lower Young's modulus yielded high bond strength. The inverse correlation between the Young's modulus of adhesive systems and dentin bond strength suggests adequate resistance of the adhesive to elastic deformation under stress, which are important properties to predict the success of the dental restoration.

Microleakage of Composite Resin Restorations Using a Type of Fifth and Two Types of Seventh Generations of Adhesive Systems: A Comparative Study

Introduction: In recent dentin adhesive systems etching of enamel/dentin are achieved simultaneously. The objective was to evaluate the microleakage of composite restorations using Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). Methods: Class V cavities were prepared on 45 extracted intact premolars with gingival margins at the cementoenamel junction and they were randomly divided into 3 groups (n=15) based on the type of adhesives: Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). After applying the adhesives, the cavities were filled with Z250 composite resin. The occlusal and gingival microleakage was evaluated using 2% basic fuchsin staining technique. Data were analyzed using Kruskal-Wallis and Bonferroni corrected Mann-Whitney U tests. Results: The mean rank of occlusal microleakage exhibited significant differences by comparison of G Bond, Clearfil S3 Bond and Single Bond2 (21.07, 30.67) and 17.27, respectively) (P=0.005). There was a significant difference in gingival microleakage of different bonding agents (34.40, 17.83 and 16.77 for G Bond, Clearfil S3 Bond and Single Bond2, respectively) (P<0.001). There was a significant difference in occlusal microleakage of Clearfil S3 Bond and Single Bond2 (P= 0.003), but no significant difference was found between Clearfil S3 Bond and G Bond (P=0.025). No significant difference was observed between occlusal microleakage by G Bond and Single Bond2 (P=0.238). The difference in gingival microleakage was significant by G Bond compare with Single Bond2 and Clearfil S3 Bond (P<0.001and P<0.001, respectively). Conclusion: The microleakage of class V composite restorations in permanent teeth using the Single Bond2 was lower than that with the use of G Bond in gingival margins. The sealing ability with Single Bond2 was superior to Clearfil S3 Bond in occlusal margin but they were equally effective at gingival margin.

Effect of water storage on ultimate tensile strength and mass changes of universal adhesives.

Background The aim of the present study was to evaluate the influence of water storage on micro tensile strength (µTS) and mass changes (MC) of two universal adhesives. Material and Methods 10 disk-shaped specimens were prepared for each adhesive; Scotchbond Universal (SCU) All-Bond Universal (ABU) and Adper Single Bond 2 (SB2). At the baseline and after 1 day and 28 days of water storage, their mass were measured and compared to estimate water sorption and solubility. For µTS test, 20 dumbbell shaped specimens were also prepared for each adhesive in two subgroups of 1 day and 28 days water storage. Results MC was significantly lower for SCU and ABU than SB2 (P < 0.05) at both time intervals. In all three adhesives, the MC was significantly lower at 28 days compared to that at 1 day (P < 0.05). Similarly, µTS was significantly higher for SCU and ABU than SB2 at both storage intervals (P < 0.05). After 28 days, µTS increased significantly for universal adhesives (P < 0.05). Conclusions MC and µTS of adhesives were both material and time dependent when stored in water; both universal adhesives showed less water sorption and higher values of µTS than the control group. Key words:Absorption, dental adhesives, dentin-bonding agents, solubility, tensile strength.

Two-year clinical performance of four adhesive strategies

Objective: To assess the clinical performance of four adhesive strategies; 3-step etch-and-rinse Adper Scotchbond Multi-Purpose (SM), 2-step etch-and-rinse (Adper Single Bond-2 [S2]), 2-step self-etch Adper Scotchbond SE (SE) and 1-step self-etch (Adper Single Bond Universal [SU]). Materials and Methods: Eighty cervical cavities exhibiting dentin carious lesions were used. Four adhesives from the same manufacturer (3M ESPE, St. Paul, MN, USA) representing different bonding strategies were used; SM (3-step etch-and-rinse), Adper S2 (2-step etch-and-rinse), SE (2-step self-etch) and SU (1-step self-etch). Cavities were restored with a nanohybrid composite resin (Z-350XT - 3M ESPE, St. Paul, MN, USA), and clinically followed up for 24 months using the modified United States Public Health Service criteria. Results: The outcome of Wilcoxon signed rank test showed no significant difference among the groups for each adhesive material at different evaluation periods ( P > 0.05). Furthermore, the Friedman test revealed that there was no significant difference between all materials in all evaluation criteria, except for marginal discoloration at 24-month evaluation period. At 24-month evaluation period, teeth restored with self-etch adhesives showed more marginal staining. Conclusions: The four bonding strategies used in the current study showed an acceptable 2-year clinical performance.

Effects of photopolymerisation on genotoxicity of composite adhesives in the comet assay

Certain in vivo studies have shown that the application of adhesives directly onto the open pulp or on a thin layer of dentin causes inflammation and pulpal abscesses. This reaction is related to toxic effects of monomers from adhesives. It has been confirmed that after proper illumination the adhesives become less toxic. The aim of the study was to examine genotoxicity of non-polymerised, partly polymerised and polymerised adhesives on isolated human lymphocytes using the alkaline Comet assay. Adper Single bond2 and Adper Easy One/3M ESPE adhesive photopolymerisation was performed by Elipar Highlight 3M ESPE halogen lamp for 0, 10 and 40 sec, at final concentrations of 100, 200, 500 and 1000 ?g/mL. With both adhesives, photopolymerisation at 0 and 10 seconds showed statistically significant increase in DNA damage in comparision to the negative control (solvent). On the other hand, after 40 seconds of photopolymerisation of both adhesives in all tested concentrations, the degree of DNA damage in Comet assay had no significant difference (P&gt;0.05, ?2 test) compared to the negative control. Therefore, only the 40 seconds of photopolymerisation prevented genotoxic effects of both adhesives in the Comet assay.

Experimental etch-and-rinse adhesive systems containing MMP-inhibitors: Physicochemical characterization and resin-dentin bonding stability

ObjectivesTo evaluate the degree of conversion (DC%), water sorption (WS), solubility (SO) and the resin–dentin bonding stability (μTBS) of experimental (EXP) etch-and-rinse adhesive systems containing MMP-inhibitors: Galardin-GAL, Batimastat-BAT, GM1489-GM1 and chlorhexidine diacetate-CHX. MethodsDC% was measured using FT-IR spectroscopy, while WS and SO were calculated based on ISO4049. Thirty-six human molars were wet ground until the occlusal dentin was exposed. The adhesive systems were applied and resin composite buildups were incrementally constructed. After 24h immersion in distilled water at 37°C, the specimens were cut into resin-dentin beams with a cross-sectional area of 1mm2. The μTBS was evaluated after 24h, 6 months and 12 months of water storage at 37°C. Adper Single Bond 2 (SB2) was used as a commercial control. The data were analyzed using ANOVA and Tukey’s HSD test. ResultsSB2 presented the highest DC% (p<0.05). CHX presented the lowest WS (p<0.05). GM1, GAL and BAT presented similar WS when compared with SB2 (p>0.05). SO was found to be not significant (p>0.05). All adhesive systems maintained μTBS stability after 6 months of water storage. Only BAT, GM1 and CHX maintained μTBs stability after 12 months of water storage. ConclusionsThe experimental adhesive systems with GM1489 and chlorhexidine diacetate presented the best physicochemical properties and preserved resin–dentin bonding stability after 12 months of water storage. Clinical significanceGM1489 could be suitable for inclusion as an MMP-inhibitor in etch-and-rinse adhesive systems to maintain resin-dentin bonding stability over time.

Effect of Restorative System and Thermal Cycling on the Tooth-Restoration Interface - OCT Evaluation.

The present study evaluated the tooth/noncarious cervical lesion restoration interface when using different adhesive systems and resin composites, submitted to thermal cycling (TC), using optical coherence tomography (OCT). Noncarious cervical lesion (NCCL) preparations (0.7 mm depth × 2 mm diameter) were performed on 60 human third molars and randomly divided into six groups, according to the adhesive system and resin composite used: group 1 = Adper Single Bond 2 (SB2) + Aelite LS Posterior (AP); group 2 = SB2 + Venus Diamond (VD); group = SB2 + Filtek Z250XT (Z250); group 4 = Clearfil SE Bond (CSE) + AP; group 5 = CSE + VD; group 6 = CSE + Z250. Selective enamel etching was performed for 30 seconds on groups 4, 5, and 6, while groups 1, 2, and 3 were etched for 30 seconds in enamel and 15 seconds in dentin. All groups were evaluated using OCT before and after TC (n=10). Images were analyzed using Image J software; enamel and dentin margins were separately evaluated. Data from OCT were submitted to PROC MIXED for repeated measurements and Tukey Kramer test (α = 0.05). No marginal gaps were observed in etched enamel, either before or after TC, for all adhesive and resin composite systems. A significant interaction was found between adhesive system and TC for the dentin groups; after TC, restorations with CSE showed smaller gaps at the dentin/restoration interface compared with SB2 for all resin composites. Increased gap percentages were noticed after TC compared with the gaps before TC for all groups. In conclusion, TC affected marginal integrity only in dentin margins, whereas etched enamel margins remained stable even after TC. Dentin margins restored with CSE adhesive system showed better marginal adaptation than those restored with SB2. Resin composites did not influence marginal integrity of NCCL restorations.

Marginal Seal of Water-Based Formulation of Light Activated Bonding Agent for Use in Combination with Adhesive Restorations

Aim: The purpose of the study was to investigate effect of water-based solvent adhesive system on micro-leakage of composite resinrestorations. Materials and methods: Class V cavities were prepared on buccal and lingual surfaces of 20 human molars, The occlusal margins were prepared in enamel while cervical ones were prepared in dentin below CEJ by one mm, and classified into four groups according to type of adhesive used five teeth each: Adper Single Bond2 was used as control, Clearfil SE Bond water-based adhesive, Clearfil S3 Bond ethanol-based adhesive, I-Bond acetone-based adhesive. All cavities were restored with Filtek Z250 composite, stored in distilled water at 37?C for 24 hours and thermal cycled. All surfaces, except for restorations and 1 mm from the margins, were coated with two layers of nail varnish. The teeth were immersed in a 3% methylene blue dye solution for 24 hours, and then rinsed in running water, blot-dried and sectioned longitudinally through center of restorations from the facial to lingual surface. The sections (10 sections for each group by n=20 readings) were blindly assessed for microleakage of dye penetration for both the occlusal and gingival margins. Data were collected and statistically analyzed. Results: Results demonstrate a comparable significantly lesser mean dye penetration in Adper single Bond2 adhesive than in other groups at enamelmargins (p<0.05) and a highly significant lesser mean dye penetration at dentin margins. Clearfil SE Bond water-based adhesive showed a significant higher mean value of dye penetration at dentin margins than either ethanol or acetone-based adhesives and a comparable non significantly lesser mean dye penetration score at enamel margins. Conclusion: Clearfil SE Bond (water-based adhesive) showed a significant higher mean value of dye penetration score at dentin margins than either ethanol or acetone-based adhesives.

Marginal microleakage of composite resin restorations bonded by desensitizing one step self etch adhesive

AimThe aim of this study was to investigate the effect of desensitizing agents on microleakage of composite resin restorations bonded by one step desensitized self etch adhesive. Materials and methodsClass V cavities (3 × 4 × 2 mm) were prepared on the buccal surfaces of 30 human molars, Teeth were classified into three groups according to the type of adhesive used (n = 10). Group 1: Adper Single Bond2. Group 2: l-bond. Group 3: is a control group of composite resin restoration without bonding agent. All cavities were restored with Filtek Z250 composite resin, stored in distilled water at 37 °C for 24 h and thermal cycled for 500 cycles. The root apices were sealed with utility wax, and all the surfaces, except for the restorations and 1 mm from the margins, were coated with two layers of nail varnish. The teeth were immersed in a 3% methylene blue dye solution for 24 h, and then rinsed in running water, blot-dried and sectioned longitudinally through the center of restorations from the facial to lingual surface. The sections were blindly assessed for microleakage of dye penetration by two independent evaluators using a stereomicroscope at 30× magnification for both the occlusal and gingival margins. Data were collected and statistically analyzed. ResultsA Mann–Whitney test demonstrated the highest significantly dye penetration rate for group 3 versus tested groups comparing the occlusal and gingival scores for each group, Wilcoxon Rank test showed significant difference for all groups. Etch and rinse adper single bond2 adhesive record a lower significant scores of dye penetration than self etch adhesive I-bond at both enamel and dentin margins. ConclusionAll adhesive systems exhibited dye penetration at both occlusal and gingival margins. Etch and rinse system is still considered a gold standard adhesive. Adper single bond2 revealed significantly less leakage compared to I-Bond.

Effect of exposure time of zinc oxide eugenol restoration on microtensile bond strength of adhesives to dentin

ObjectiveThe purpose of this study was to evaluate the influence of different exposure times (24h, 7 days and 45 days) of zinc oxide eugenol cement (ZOE) on microtensile bond strength (μTBS) of etch-and-rinse and self-etch adhesives. MethodsOcclusal enamel of 40 human molars was removed. Zinc oxide eugenol restoration was placed on the dentin surface and left for different times (24h, 7 days or 45 days). After ZOE removal or over fresh dentin (control) were restored using Adper Single Bond 2 (SB2) or Clearfil S3 Bond (CS3). After 24h, each tooth was longitudinally sectioned, to obtain bonded sticks that were tested under tension (0.5mm/min). Two-way ANOVA and Tukey's test (α=0.05) were used to compare μTBS. ResultsA decrease in μTBS was observed for SB2 after 24h (46.8±3.4MPa) when compared to the control (60.4±5.2MPa, p<0.05). Similarly, a decrease was observed for CS3 after storage for 24h (20.4±2.2MPa) and 7 days (18.1±2.1MPa), when compared with a control group (39.1±4.2MPa, p<0.05). After 45 days, both adhesives SB2 and CS3 show the same μTBS compared to controls. Under all conditions, SB2 showed higher μTBS values than CS3 (p<0.001). ConclusionThe results suggest that ZOE has negative effects on microtensile bond strength after 24h.

Microtensile bond strength of composite-to-composite repair with different surface treatments and adhesive systems

Objectives: The purpose was to investigate the effect of different surface treatments and bonding agents on the repair bond strength of different resin-based restorative materials by microtensile bond strength (μTBS) testing protocol. Materials and Methods: 24 Grandio SO(VOCO) and 24 Filtek Z250(3 M) resin composite blocks were prepared. Half of the samples (N = 12) were diamond bur-roughened and the other half (N = 12) were sandblasted by 50 μm aluminum oxide particles. They were further divided into four sub-groups (n = 3) and received the following: Sub-Group1: Adper Single Bond2 (Etch&Rinse) (3 M); Sub-Group2: Clearfil SE (Self-etch) (Kuraray); Sub-Group3: Beauty Bond (HEMA-free all-in-one) (Shofu); Sub-Group4: All Bond3 (HEMA-free, hydrophobic, etch&rinse) (Bisco). The samples were repaired by Filtek Z250 to form a block. All of the resultant sub-groups combinations consisted of one of the composite type, surface treatment type, and adhesive systems. A total of 18 groups were prepared including 2 homogeneous blocks. They were thermocycled and μTBS measurements were performed. Data were statistically analyzed with Kruskall–Wallis and Mann–Whitney U tests. Results: The experimental regroups’ μTBS reached to 34.67–66.36% and 43.44–95.52% of the cohesive bond strength for Grandio SO and Z250, respectively. The pre-existing composite type is found to be statistically important. When the surface is bur-finished Grandio performed better; when air-abrasion is considered Z250 showed higher bond strength. All-in-one adhesive system produced the weakest bond strength at all parameters. Conclusion: It may be suggested that when the pre-existing composite is unknown, air-abrasion may be performed with etch&rinse or two-step self-etch adhesives.

Shear bond strength and ultrastructural interface analysis of different adhesive systems to Er:YAG laser-prepared dentin

The aim of this study was to evaluate the shear bond strength (SBS) of a microhybrid composite resin bonded with three different adhesive systems to Er:YAG laser- (EL) or bur-prepared dentin surfaces and to analyze the quality and ultrastructure of the adhesive-dentin interfaces by scanning electron microscopy (SEM). The specimens prepared for SBS test and SEM analysis were randomly assigned to eight groups (G1-G8): G1, EL (Fidelis PlusIII, Fotona) + Clearfil S3 Bond (C3S); G2, EL + AdperSE Plus (SE); G3, EL + laser etch + Adper Single Bond2 (SB2); G4, EL + acid etch + SB2; G5, EL + SB2 (no etching); G6, bur + acid etch + SB2; G7, bur + S3; G8, bur + SE. Laser was used in very short pulse mode at a setting of 200mJ/20Hz for dentin preparation and at 80mJ/10Hz for dentin etching. Bond strength test: 3.5 × 2.0mm cylindrical molds were placed onto adhesives and filled with the composites. After 24h in distilled water, SBS was tested at a crosshead speed of 0.5mm/min. SEM analysis: The dentin-adhesive interfaces were evaluated for the ultrastructure of hybrid layer. Data of SBS (MPa) were statistically analyzed by ANOVA and Tukey HSD. ER:YAG laser-prepared dentin has demonstrated significantly more SBS (p < 0.01) for SE when compared to bur-prepared dentin. No significancies (p > 0.05) in SBS have been determined between the total-etch adhesive applied groups with regard to etching types. SEM analysis revealed that hybrid layers obtained in Er:YAG laser-irradiated dentin exhibited more irregular and non-homogeneous pattern than the conventionally prepared dentin. In conclusion, SE Bond demonstrated superior results in Er:YAG laser-ablated dentin compared to bur-prepared dentin.

Micro-shear bond strength of adhesive resins to enamel at different relative humidity conditions

This study tested whether exhaled humid conditions would affect the adhesion of etch-and-rinse, two-step and one-step self-etch adhesive resins to enamel. Enamel surfaces of human maxillary anterior teeth (N=240, n=20) were exposed to four humid conditions (H1: 63-68%, H2: 73-78%, H3: 93-98%, H4: 36-45% RH) during bonding with Adper Single Bond 2 (SB2), Clearfil SE Bond (CSE) and Adper Easy Bond (AEB). Specimens were stored in distilled water at 37 ºC for 24 h and tested to failure using micro-shear bond strength (μSBS) test. Data were analyzed using two-way ANOVA and Tukey's test (p<0.05). The μSBS to enamel with SB2, CSE and AEB was not significantly affected by humidity parameters. AEB resulted in significantly lower μSBS in all conditions. The frequency of adhesive failures was the highest at H2, H3 for SB2, H3 for CSE and H1-4 for AEB indicating that humidity conditions may decrease adhesion quality to enamel.