2-step Self-etch Research Articles

Is There Evidence that Three-step Etch-and-Rinse Adhesives Have Better Retention Rates than One-step Self-etch Adhesives in Noncarious Cervical Lesions? A Systematic Review and Meta-Analysis.

A systematic review and meta-analysis was conducted to compare the retention rates of 3-step etch-and-rinse (3ER) adhesives with 1-step self-etch (1SE) adhesives in noncarious cervical lesions (NCCLs). The secondary outcomes were marginal integrity and marginal discoloration. Only randomized clinical trials (RCTs) that compared 1SE with 3ER in NCCLs were included. Controlled vocabulary and keywords were combined in the search strategy for PubMed/Medline, LILACS, BBO, Web of Science, Cochrane Library, grey literature, and IADR abstracts (1990-2018). The Cochrane Risk of Bias tool (RoB) was applied to eligible studies. Meta-analyses were conducted for retention rate and secondary outcomes at different follow-up times, using the random effects model. Heterogeneity was assessed with the Cochran Q test and I2 statistics. The GRADE approach was used to assess the quality of the evidence. After the removal of duplicates, title and abstract screening, 18 studies remained. Of these, 15 studies were used for meta-analysis. Fourteen out of these 15 were judged at "unclear" risk and 1 at "low" risk of bias. No significant differences between groups were observed in the different follow-up periods for retention rates 12 to 24 months (p = 0.66), 24 to 36 months (p = 0.21) and 60 months (p = 0.96). A significant difference in marginal integrity was found at 12 to 24 months (p = 0.04) and in marginal discoloration at 12 to 24 months (p = 0.003). There is no evidence that 3-step ER adhesives have better retention rates than 1-step SE adhesives in NCCLs.

Fracture toughness of different adhesive/dentin interfaces analyzed by finite element stress analysis

Objectives: Study aimed to assess the fracture toughness of different dentin adhesive approaches and to evaluate the stress distribution at the bond interface during fracture toughness testing by finite element analysis. Materials and Methods: Specimens for chevron-notched beam fracture toughness (CNB) were prepared with dimensions of (3.0 mm × 4.0 mm × 20 mm) according to ISO 24370:2005 standard. Chevron notch was prepared at the adhesive–dentin interface using a highly polished stainless steel spacer. Four different dentin adhesives approaches were used total-etch 3 and 2 step and self-adhesives 2 and 1 step. A total of 60 specimens were prepared for each adhesive approach (n=15). Each specimen was loaded until failure in a 4-point bend test setup and the fracture toughness was calculated according to the ISO specifications. Finite element modeling of the specimens was carried out in order to analyze stress distribution during fracture toughness testing. Data were analyzed by one-way ANOVA followed by tukey‘s post hoc test with significant level at p < 0.001 level (p= 0.0001).. Results: Solobond plus 3-step etch-and-rinse showed the highest mean fracture toughness (1.78 MPam1/2) Whereas, Futurabond M+ 1-step self-etch showed the lowest value (1.13 MPam1/2). These finding were supported by finite element analysis which showed stresses to concentrate at the adhesive–dentin interface during fracture toughness loading and crack propagation. Conclusion: The adhesive approach has a strong effect on the fracture toughness of the adhesive–dentin interface. the 3-step etch-and-rinse approach showing the highest mean fracture toughness while 1-step self-etch approach showing the lowest value.

Effect of Saliva Decontamination on Bond Strength of 1-step Self-etching Adhesives to Dentin of Primary Posterior Teeth

이 연구의 ëª©ì ì€ ìœ ì¹˜ì—ì„œ 한 단계 자가부식 ì ‘ì°©ì œë¥¼ 이용한 ë ˆì§„ìˆ˜ë³µ 시 타액오염 후 ì²˜ì¹˜ê³¼ì •ì— 따른 미세인장강도를 비교하는 것이다. ê±´ì „í•œ ìœ êµ¬ì¹˜ë¥¼ ì ‘ì°©ì œ 사용에 따라 각각 Scotchbond™ Universal Adhesive (SBU), All-Bond Universal® (ABU), and Tetric® N Bond Universal (TBU)의 3 그룹으로 나누어 무작위로 분배하였다. 각 그룹은 ì ‘ì°©ì œ 도포 후 ì²˜ì¹˜ê³¼ì •ì— 따라 7가지 하위분류로 나누었다. Subgroup I은 대조군으로써, 타액오염 없이 ì œì¡°ì‚¬ ê¶Œê³ ì‚¬í•­ì— 따라 ì ‘ì°©ì œë¥¼ ì ìš©í•˜ì˜€ë‹¤. Subgroup II - IV는 ì ‘ì°©ì œ 광중합 ì „ì— 타액오염을 ì‹œí–‰í•˜ì˜€ê³ , subgroup V - VII는 ì ‘ì°©ì œ 광중합 후에 타액오염을 시행하였다. ê·¸ 후 subgroup II, V는 ê±´ì¡°, subgroup III, IV는 수세 후 ê±´ì¡°, subgroup IV, VII는 수세 후 ê±´ì¡°, ê·¸ë¦¬ê³ ì ‘ì°©ì œ 재도포를 시행하였다.SBU와 ABU에서 subgroup I, IV, VII의 미세인장강도가 subgroup II, III, V, VI의 미세인장강도보다 ìœ ì˜í•˜ê²Œ 높았다. TBU에서 subgroup I, IV의 미세인장강도가 subgroup II, III, V, VI의 미세인장강도보다 ìœ ì˜í•˜ê²Œ 높았다. 이 연구 ê²°ê³¼, 임상가는 한 단계 자가부식 ì ‘ì°©ì œë¥¼ 이용한 ë ˆì§„ 수복 시 타액과 수분의 오염으로부터 ì² ì €í•˜ê²Œ 격리를 지켜야 하지만 그럼에도 ë¶ˆêµ¬í•˜ê³ íƒ€ì•¡ì˜¤ì—¼ì´ 발생하였다면, 수세 및 ê±´ì¡° 후 ì ‘ì°©ì œë¥¼ ìž¬ë„í¬í• ê²ƒì„ 권장한다.

Bonding to enamel using alternative Enamel Conditioner/etchants

ObjectiveEnamel bond durability of three new alternative etchants combined with three representative adhesives was determined. MethodsThe ‘immediate’ and ‘aged’ micro-tensile bond strength (μTBS) of the 3-step etch&rinse adhesive OptiBond FL (‘O-FL’, Kerr), 2-step self-etch (SE) adhesive Clearfil SE Bond 2 (‘C-SE2’, Kuraray Noritake) and universal adhesive Adhese Universal (‘ADU’, Ivoclar Vivadent) were measured when bonded to enamel following either a proprietary organic acid-containing Enamel Conditioner (‘EC’, Shofu), a phosphoric-acid monomer-containing Multi Etchant (‘ME’, Yamakin: 10-methacryloyloxy tetraethylene glycol dihydrogenphosphate or MTEGP), or a metal salt-based ZON etchant (‘ZON’, Ivoclar Vivadent: ZrO(NO3)2). All alternative etchants were used in replacement of phosphoric acid, the latter (K-Etchant, Kuraray Noritake) also used with O-FL and ADU, in addition to C-SE2 that was solely used in SE mode (controls). The enamel-etching patterns and de-bonded fracture surfaces were examined by SEM, while the interfaces with enamel were ultra-morphologically characterized by TEM. ResultsNo statistically significant difference in immediate and aged μTBS, obtained by combining the three alternative etchants with the three adhesives, was recorded as compared with the respective controls, except for ME combined with O-FL. Upon aging, significant reduction in μTBS was recorded for the ME/C-SE2 and ME/ADU combinations. The percentage of adhesive failures increased with aging. SEM revealed similar etching patterns produced by EC and ZON as by classic phosphoric-acid etching, for which also numerous micro-resin tags at the adhesive-enamel interface were disclosed. SignificanceDurable bonding to enamel was generally obtained for all etchant/adhesive combinations with the exception of the ME/O-FL combination.

The effect of dentin pre-treatment with activated riboflavin on the bond strength of a two-step self-etch adhesive system.

The cross-linking of collagen fibers in the hybrid layer has been suggested as a way to create more durable bonds. This study evaluated the effect of visible light-activated riboflavin (RF) as a cross-linking agent on the durability of the dentin microtensile bond strength (μTBS) in a 2-step self-etch (SE) adhesive system. The occlusal surfaces of 21 human premolar teeth were ground down to expose the dentin, and were then randomly divided into 3 groups. The Clearfil® SE Bond was used in the control group. In the RF/BL group, a 0.1 wt% aqueous solution of RF was applied to the dentin surface before applying the adhesive and irradiating with blue light (BL) for 2 min. In the 3rd group, the RF-P/BL group, the RF powder was added to the adhesive primer (P) at a concentration of 0.1 wt%. The teeth were built up using composite resin. After thermocycling, 14 resin-dentin beams from each group were prepared and stored in water for 3 months. The μTBS was determined and the data was analyzed using a linear model with a generalized estimating equation (GEE) (p = 0.05). The highest and the lowest μTBS belonged to the control group (41.15 ±3.50 MPa) and the RF-P/BL group (19.84 ±3.80 MPa), respectively. The mean μTBS in the control group was significantly higher than in the RF/BL and RF-P/BL groups (p < 0.001), but no significant difference was found between the RF/BL and RF-P/BL groups (p = 0.598). Pre-treatment of dentin surfaces with RF activated with BL had a negative impact on the μTBS of the Clearfil SE Bond as a 2-step SE adhesive.

Do Universal Adhesives Benefit from an Extra Bonding Layer?

Universal adhesives use a combined primer/bonding resin applied either in 2-step etch-and-rinse (2-E&R) or 1-step self-etch (1-SE) mode. This study investigated whether three universal adhesives would benefit from an extra bonding layer (EBL), essentially making them 3-step E&R (3-E&R) and 2-SE adhesives, respectively. Microtensile bond strengths (μTBSs) to bur-cut dentin of Clearfil Universal Bond Quick (C-UBq, Kuraray Noritake), G-Premio Bond (G-PrB, GC) and Prime&Bond Active (P&Ba, Dentsply Sirona) were compared to those of the 2-SEa Clearfil SE Bond 2 (C-SE2, Kuraray Noritake) which was also employed in 3-E&R mode. A split-tooth design was applied with each adhesive used in E&R and SE mode on each tooth, half without/with EBL (C-SE2 Bond). All adhesives were light cured after application of the final layer. The μTBS of one-third of the specimens was measured after 1-month water storage without thermocycling (TC), with the remaining two-thirds aged with 25,000 and 50,000 TCs. All μTBSs were statistically analyzed using a linear mixed-effects model with specific contrasts (p < 0.05). Overall, the four variables (adhesive, bonding mode, EBL, aging) significantly influenced μTBS. Solely G-PrB benefited from EBL when applied in SE mode. In E&R mode, P&Ba generally resulted in the highest µTBSs, C-UBq presented with intermediate and G-PrB with the lowest µTBSs, where the latter was significantly lower than the µTBSs recorded for C-SE2. In SE mode, P&Ba generally resulted in the highest µTBSs in 1- and 2-SE mode. Equally high µTBSs were recorded for G-PrB in 2-SE mode with EBL. Lower µTBSs were recorded for G-PrB in 1-SE mode and for C-UBq in 1- and 2-SE mode. The overall effect of EBL on immediate and aged bonding efficacy depended on the specific universal adhesive and its bonding mode.

Effect of Galardin and its Solvents on the Microtensile Bond Strength of Different Adhesive Systems to Dentin

Objective: To evaluate the effect of a synthetic inhibitor of MMPs (Galardin) and its solvents [ethanol and dimethyl sulfoxide (DMSO)] on the microtensile bond strength (µTBS) of adhesive systems to dentin. Material and Methods: Sound human third molars (n=180) were randomly assigned into 5 based on solution type: DMSO; ethanol; Galardin + DMSO; Galardin + ethanol; and distilled water as control. Then were further subdivided into 6 based on the adhesive system, i.e. 3-step and 2-step etch-and-rinse (ER), one-step and 2-step self-etch (SE) and universal in ER and SE strategies. The samples underwent a 500-round thermocycling procedure at 5±5/55±5°C and were sectioned into 1-mm2 pieces perpendicularly in a cutting machine. The µTBS was measured at a strain rate of 1 mm/min. Data were analyzed with two-way ANOVA and post hoc Games-Howell tests (p<0.05). Results: The adhesive system and the solution had significant effects on the µTBS (p<0.001). The universal adhesive in the SE mode resulted in a significant decrease in µTBS compared to the other adhesives (p<0.05). Ethanol, too, resulted in a significant decrease in µTBS compared to other solutions (p<0.05). Conclusion: Galardin and its solvents, except for ethanol, had no detrimental effects on the immediate µTBS.

Internal and marginal adaptation of high-viscosity bulk-fill composites in class II cavities placed with different adhesive strategies.

The aim of this study was toevaluate internal and marginal adaptation of high-viscosity bulk-fill composites to enamel and dentin with a self-etch (SE) and an etch-and-rinse adhesive (ER) without and with artificial aging. 128 MOD cavities in extracted human molars were prepared, randomly assigned to 8 groups (n = 16), bonded with either OptiBond FL (OFL, ER) or Xeno V+ (X, SE), and restored in 4mm horizontal bulk layers with SonicFill (SF), Tetric EvoCeram Bulk fill (TEC), and x-tra fil (XF). Incremental layering technique with Premise (P) served as control. Half of the specimens each (n = 8) were subjected either to water storage (1day, 37°C) or prolonged storage (180days) and thereafter thermocycling. Replicas were analyzed for marginal gap formation. After sectioning, interfacial adhesive defects were assessed. Results were statistical analyzed. (1) Internal adaptation: Except for TEC/OFL at enamel without artificial aging, no significant differences between bulk-fill composites and the control were observed. All groups at dentin with OFL showed less internal adhesive defects than that with X (p < 0.05). (2) Marginal adaptation: Nosignificant differences were observed between bulk-fill composites and controlexcept for P after artificial aging (p > 0.05). All other composites, regardless of artificial aging, formed significantly more marginal gaps at enamel with X compared to with OFL (p ≤ 0.05). Simplified restorations with high-viscosity bulk-fill composite showed comparable internal and marginal adaptation to incrementally placed fillings. A superiority of the 3-step ER approach was seen compared to the 1-step SE adhesive irrespective of the bulk-fill composite used.

Effect of six month storage on microtensile bond strength of new elective etching adhesive system on dentin in self-etching or etch-and-rinse approach

Abstract The aim of this study was to evaluate the microtensile bond strength (μTBS) to dentin of an elective etching adhesive system applied in etch-and-rinse (ER) or self-etching (SE) mode after 6-months of storage in water. Thirty-six caries-free, human third molars were collected and stored in a 0.1% thymol solution. Dentin surfaces were exposed by 600-grit silicon carbide paper and teeth were divided into six groups ( n = 6), according to the adhesive systems: a 2-step SE system, Clearfil SE Bond (CSE); a 1-step SE adhesive Adper Prompt L-Pop (LPOP); Scotchbond Universal applied as a 1-step SE adhesive (SBU-SE) and applied as a 2-step ER adhesive (SBU-ER); and two 2-step ER adhesives: Adper Single Bond Plus (SBP) and Optibond Solo Plus (OSP). Composite build-ups were constructed with TPH3 and cured in three increments of 2 mm each. Specimens were sectioned with a slow-speed diamond saw under water in X and Y directions to obtain bonded beams that were tested to failure in tension at a crosshead speed of 1.0 mm/min after one week or 6 months of storage in water. Statistical analyses were computed using Repeated-Measures ANOVA and Fisher’s LSD Tests ( α = 0.05). There were no significant differences between 1-week and 6-months. SBU-ER and SBUSE showed the highest μTBS values and statistically differed from LPOP (Fisher’s LSD). The SBP, OSP, and CSE groups showed intermediary μTBS and did not differ statistically from SBU-ER, SBUSE or LPOP, which presented the lowest μTBS values. The use of elective etching adhesive system in dentin with the etch-and-rinse or self-etching approach did not compromise the bond strength and showed stable bonds after six months of storage in water.

Mini-interfacial fracture toughness as a new validated enamel-bonding effectiveness test

Today׳s most commonly applied bonding effectiveness tests are criticized for their high variability and low reliability, the latter in particular with regard to measuring the actual strength of the adhesive interface. Objectives: in continuation of previous research conducted at dentin, we hereby aimed to validate the novel mini-interfacial fracture toughness (mini-iFT) test on its applicability to assess bonding effectiveness of contemporary adhesives when bonded to enamel. Methods: The 3-step etch&rinse (E&R) adhesive OptiBond FL (Kerr), the 2-step self-etch (SE) adhesive Clearfil SE Bond (Kuraray Noritake) and the two multi-mode adhesives Clearfil S3 Bond Plus (Kuraray Noritake) and Scotchbond Universal (3M ESPE), both used following a 2-step E&R and 1-step SE mode, were applied to clinically relevant, flattened enamel surfaces. A composite (Filtek Z100; 3M ESPE) build-up was made in layers. After 1-week water storage at 37°C, all specimens were sectioned perpendicular to the interface to obtain rectangular sticks. A mini-iFT notch was prepared at the adhesive-enamel interface using a thin diamond blade under water cooling. Finally, the specimens were loaded in a 4-point bending test until failure. Results: the mini-iFT onto human enamel was significantly higher for the adhesives applied in E&R mode versus those applied in SE mode. The lowest mini-iFT was found for the adhesives applied following a 1-step SE approach. SEM fracture analysis revealed that all fractures originated at the adhesive-enamel interface and that the induced crack propagated preferentially along this interface. Conclusion: mini-iFT appeared a valid alternative method to assess the mechanical properties of adhesive-enamel interfaces.

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.

Influence of a hydrophobic resin coating on the bonding efficacy of three universal adhesives

ObjectivesTo evaluate the effect of an additional hydrophobic resin coating (HE) on the resin–dentine microtensile bond strengths (μTBS), nanoleakage (NL), and in situ degree of conversion (DC) of three universal adhesives used in the etch-and-rinse (ER) and the self-etch (SE) modes. MethodsSixty caries-free extracted third molars were divided into 12 groups according to the combination of the factors adhesive (All-Bond Universal [ABU]; G-Bond Plus [GBP] and Scotchbond Universal [SBU]), adhesive strategy (ER and SE), and the use of HE (Heliobond; yes or no). After restorations were constructed, specimens were stored in water (37°C/24h) and sectioned into resin–dentine beams (0.8mm2) to be tested under tension (0.5mm/min). Selected beams from each tooth were used for DC quantification and for NL evaluation. Data from each adhesive were analyzed with two-way ANOVA and Tukey's test (α=0.05). ResultsABU and GBP resulted in higher μTBS in the ER mode. The use of HE increased the μTBS of ABU and GBP only in the SE mode. Lower NL was observed for SBU and ABU in the ER mode+HE, and for GBP in the SE mode+HE. SBU and GBP showed higher DC when used in the ER mode, which was increased with HE application. The DC of ABU was similar in all conditions. ConclusionsThe conversion of 1-step SE to 2-step SE may increase the μTBS and DC of current universal adhesives. The reduction in the NL is more dependent on the adhesive composition than on the bonding strategy.

Shear Bond Strength and Fracture Analysis of Human vs. Bovine Teeth

PurposeTo evaluate if bovine enamel and dentin are appropriate substitutes for the respective human hard tooth tissues to test shear bond strength (SBS) and fracture analysis.Materials and Methods80 sound and caries-free human erupted third molars and 80 freshly extracted bovine permanent central incisors (10 specimens for each group) were used to investigate enamel and dentine adhesion of one 2-step self-etch (SE) and one 3-step etch and rinse (E&R) product. To test SBS the buccal or labial areas were ground plane to obtain appropriate enamel or dentine areas. SE and E&R were applied and SBS was measured prior to and after 500 thermocycles between +5 and +55°C. Fracture analysis was performed for all debonded areas.ResultsANOVA revealed significant differences of enamel and dentin SBS prior to and after thermocycling for both of the adhesives. SBS- of E&R-bonded human enamel increased after thermocycling but SE-bonded did not. Bovine enamel SE-bonded showed higher SBS after TC but E&R-bonded had lower SBS. No differences were found for human dentin SE- or E&R-bonded prior to or after thermocycling but bovine dentin SE-bonded increased whereas bovine dentine E&R-bonded decreased. Considering the totalized and adhesive failures, fracture analysis did not show significances between the adhesives or the respective tooth tissues prior to or after thermocycling.ConclusionAlthough SBS was different on human and bovine teeth, no differences were found for fracture analysis. This indicates that solely conducted SBS on bovine substrate are not sufficient to judge the perfomance of adhesives, thus bovine teeth are questionnable as a substrate for shear bond testing.

The Clinical Effectiveness of Various Adhesive Systems: An 18-Month Evaluation

The aim of this clinical trial was to compare the clinical performance of three different adhesive systems over 18 months in noncarious cervical lesions (NCCLs). Thirty patients, with at least three noncarious cervical lesions, were enrolled in the study. One operator randomly restored a total of 90 lesions with resin composite (Herculite XRV). The restorations were bonded with either Optibond FL (OF), three-step total-etch; Optibond Solo Plus (OS), two-step total-etch; or Optibond All-In-One (OA), one step self-etch. The restorations were clinically evaluated at baseline and after six, 12, and 18 months using the eight United States Public Health Services criteria. Data were analyzed using Friedman and Wilcoxon signed ranks tests (p<0.05). After 18 months, the retention rate was (OF) 96.5%, (OS) 93.1%, and (OA) 89.7%. Differences among the three adhesive systems for evaluated criteria were not observed in comparison of the mean Alfa score percentages. There was a significant increase in marginal discoloration for (OA) adhesive after 18 months compared with baseline (p=0.011). Other restoration criteria had no statistically significant differences among the three adhesives (p>0.05). With the exception of marginal discoloration, the clinical effectiveness of three types of adhesive systems in NCCLs was acceptable after 18 months. However, using the one-step self-etch adhesive may lead to some marginal discolorations.

Influence of tooth age and etching time on the microtensile bond strengths of adhesive systems to dentin.

1. To evaluate the effect of tooth age on the microtensile bond strengths (µTBS) of various adhesive systems to dentin; 2. To evaluate the effect of different etching times on the microtensile bond strengths of different adhesive systems to young vs mature dentin. One hundred twenty intact human teeth were mechanically ground to expose midcoronal dentin and were randomly assigned to three groups (n = 40) according to subjects' age in years: 15 to 25, 35 to 45, and >= 55. Within each group, specimens were further randomized into 8 subgroups according to adhesive (etch-and-rinse 3- and 2-step; self-etching 2- and 1-step) and etching time (manufacturer instructions vs extended). Resin composite was applied to the treated surfaces, and after 24 h, all specimens were processed for microtensile bond strength testing. Data were analyzed by factorial ANOVA and Tukey's test (p = 0.05). µTBS values ranged from 10.9 MPa (2-step self-etching, extended etching time, age group 15 to 25) to 50.7 MPa (1-step self-etching, extended etching time, age group >= 55). With only one exception, tooth age and etching time had no significant effect on the bond strengths of the adhesives to dentin. The 2-step self-etching system had lower bond strengths than the other systems, regardless of etching time or tooth age. Tooth age and etching time did not affect the dentin bond strengths of the adhesives tested.

An in vitro evaluation of leakage of two etch and rinse and two self-etch adhesives after thermocycling.

Our experiment evaluated the microleakage in resin composite restorations bonded to dental tissues with different adhesive systems. 40 class V cavities were prepared on the facial and lingual surfaces of each tooth with coronal margins in enamel and apical margins in cementum (root dentin). The teeth were restored with Z100 resin composite bonded with different adhesive systems: Scotchbond Multipurpose (SBMP), a 3-step Etch and Rinse adhesive, Adper Scotchbond 1 XT (SB1), a 2-step Etch and Rinse adhesive, AdheSE One (ADSE-1), a 1-step Self-Etch adhesive, and AdheSE (ADSE), a 2-step Self-Etch adhesive. Teeth were thermocycled and immersed in 50% silver nitrate solution. When both interfaces were considered, SBMP has exhibited significantly less microleakage than other adhesive systems (resp., for SB1, ADSE-1 and ADSE, P = 0.0007, P < 0.0001 and P < 0.0001). When enamel and dentin interfaces were evaluated separately, (1) for the Self-Etch adhesives, microleakage was found greater at enamel than at dentin interfaces (for ADSE, P = 0.024 and for ADSE-1, P < 0.0001); (2) for the Etch and Rinse adhesive systems, there was no significant difference between enamel and dentin interfaces; (3) SBMP was found significantly better than other adhesives both at enamel and dentin interfaces. In our experiment Etch and Rinse adhesives remain better than Self-Etch adhesives at enamel interface. In addition, there was no statistical difference between 1-step (ADSE-1) and 2-step (ADSE) Self-Etch adhesives.

Effect of thermal cycling on microtensile bond strengths of various adhesives to dentin

Normal 0 21 false false false TR X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:Normal Tablo; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Times New Roman; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi;} Objectives : T he objective of this study was to evaluate the effect of thermal cycling on microtensile bond strengths (MTBS) of various adhesives to dentin. Methods: Three adhesive systems including a 1-step self-etch adhesive system (G-Bond), a 2-step self-etch adhesive system (AdheSE), and an e tch&rinse adhesive system ( Prime & Bond NT) were evaluated. Twenty-four extracted molars were used. After grinding the coronal enamel surface, the teeth were randomly divided into 6 groups ( n =4) (G-Bond, G-Bond+thermal cycling, AdheSE, AdheSE+thermal cycling, Prime & Bond NT, and Prime & Bond NT+thermal cycling). Adhesives were applied according to each manufacturer’s instructions followed by resin composite polymerization. Groups without thermal cycling were stored in distilled water at 37 0 C for 24 hours and used for immediate testing of the MTBS. Groups with thermal cycling were subjected to thermocycling (10.000 cycles between 5 0 C and 55 0 C, for a dwell time of 30 seconds). For MTBS test, teeth were sectioned occluso-gingivally into a serial slabs and further sectioned into composite-dentin sticks. Testing was performed on a universal testing machine at a crosshead speed of 1.0 mm/min. One-way ANOVA and post hoc Tukey-Kramer multiple comparisons tests ( α =0.05) were performed on all data. Results: The results of the MTBS test showed that the highest bond strengths were observed in e tch&rinse adhesive groups (3 and 3T). A statistically significant difference in MTBS was found between group 1 and group 1T ( p p =1.000). Conclusions: Contrary to result with 1 -step self-etch adhesive , thermal cycling was found ineffective on the MTBS of the 2 -step self-etch and e tch&rinse adhesive systems. Keywords: Adhesive, thermal cycling, microtensile bond strength.

Correlation between microtensile bond strength data and clinical outcome of Class V restorations

Objective To determine if the results of resin–dentin microtensile bond strength (μTBS) is correlated with the outcome parameters of clinical studies on non-retentive Class V restorations. Methods Resin–dentin μTBS data were obtained from one test center; the in vitro tests were all performed by the same operator. The μTBS testing was performed 8 h after bonding and after 6 months of storing the specimens in water. Pre-test failures (PTFs) of specimens were included in the analysis, attributing them a value of 1 MPa. Prospective clinical studies on cervical restorations (Class V) with an observation period of at least 18 months were searched in the literature. The clinical outcome variables were retention loss, marginal discoloration and marginal integrity. Furthermore, an index was formulated to be better able to compare the laboratory and clinical results. Estimates of adhesive effects in a linear mixed model were used to summarize the clinical performance of each adhesive between 12 and 36 months. Spearman correlations between these clinical performances and the μTBS values were calculated subsequently. Results Thirty-six clinical studies with 15 adhesive/restorative systems for which μTBS data were also available were included in the statistical analysis. In general 3-step and 2-step etch-and-rinse systems showed higher bond strength values than the 2-step/3-step self-etching systems, which, however, produced higher values than the 1-step self-etching and the resin modified glass ionomer systems. Prolonged water storage of specimens resulted in a significant decrease of the mean bond strength values in 5 adhesive systems (Wilcoxon, p < 0.05). There was a significant correlation between μTBS values both after 8 h and 6 months of storage and marginal discoloration ( r = 0.54 and r = 0.67, respectively). However, the same correlation was not found between μTBS values and the retention rate, clinical index or marginal integrity. Significance As μTBS data of adhesive systems, especially after water storage for 6 months, showed a good correlation with marginal discoloration in short-term clinical Class V restorations, longitudinal clinical trials should explore whether early marginal staining is predictive for future retention loss in non-carious cervical restorations.

Microtensile bond strength of three simplified adhesive systems to caries-affected dentin

The purpose of the study was to determine the microtensile bond strength of three different simplified adhesive systems to caries-affected dentin. Fifteen extracted human molars with primary carious lesions were ground flat until dentin was exposed. Soft caries-infected dentin was excavated with the help of caries detector dye. On the remaining hard dentin, a standardized smear layer was created by polishing with 600-grit SiC paper. Teeth were divided into three groups and treated with one of the three tested adhesives: Adper Scotchbond 1 XT (3M ESPE), a 2-step etch-andrinse adhesive, Clearfil S3 Bond (Kuraray), a 1-step self-etching or all-in-one adhesive, and Clearfil SE Bond (Kuraray), a 2-step self-etching adhesive. Five-mm-thick composite buildups (Z-250, 3M ESPE) were built and light cured. After water storage for 24 h at 37ºC, the bonded specimens were sectioned into bars (1.0 x 1.0 mm; n = 20 to 30). Microtensile bond strength of normal dentin specimens and caries-affected dentin specimens was measured in a universal testing machine (crosshead speed = 1 mm/min). Data were analyzed using two-way ANOVA and Tukey's post-hoc test (p < 0.05). No significant differences in bond strength values to normal dentin between the three adhesives were found. Adper Scotchbond 1 XT and Clearfil S3 Bond showed significantly lower bond strength values to caries-affected dentin. For Clearfil SE Bond, bond strength values to normal and caries-affected dentin were not significantly different. All the tested simplified adhesives showed similar bond strength values to normal dentin. For the tested 2-step etch-and-rinse adhesive and the all-in-one adhesive, the bond strength values to caries-affected dentin were lower than to normal dentin.

Ultrastructural characterization of tooth–biomaterial interfaces prepared with broad and focused ion beams

Current available techniques for transmission electron microscopy (TEM) of tooth–biomaterial interfaces are mostly ineffective for brittle phases and impair integrated chemical and morphological characterization. Objectives The aims of this study were (1) to determine the applicability of new focused ion beam (FIB) and broad ion beam (BIB) techniques for TEM preparation of tooth–biomaterial interfaces; (2) to characterize the interfacial interaction with enamel and dentin of a conventional glass-ionomer (Chemfil Superior, DeTrey Dentsply, Germany), a 2-step self-etch (Clearfil SE, Kuraray, Japan) and a 3-step etch-and-rinse (OptiBond FL, Kerr, USA) adhesives; and (3) to characterize clinically relevant interfaces obtained from actual Class-I cavities. Methods After bonding to freshly extracted human third molars, non-demineralized and non-stained sections were obtained using the FIB/BIB techniques and examined under TEM. Results The main structures generally disclosed in conventional ultramicrotomy samples were recognized in FIB/BIB-based ones. There were not any major differences between FIB and BIB concerning the resulting ultrastructural morphology. FIB/BIB-sections enabled to clearly resolve sub-micron hydroxyapatite crystals on top of hard tissues and the interface between matrix and filler in all materials, even at nano-scale. Some investigated interfaces disclosed areas with a distinct “fog” or “melted look”, which is probably an artifact due to surface damage caused by the high-energy beam. Interfaces with enamel clearly disclosed the distinct “keyhole” shape of enamel rods sectioned at 90°, delimited by a thin electron-lucent layer of inter-rod enamel. At regions where enamel crystals ran parallel with the interface, we observed a lack of interaction and some de-bonding along with interfacial void formation. Significance The FIB/BIB methods are viable and reliable alternatives to conventional ultramicrotomy for preparation of thin sections of brittle and thus difficult to cut biomaterial–hard tissue interfaces. They disclose additional ultrastructural information about both substrates and are more suitable for advanced analytic procedures.