Search

Objective: This 24-month, double-blind, split-mouth randomized equivalence clinical trial compared the clinical performance of a bulk-fill thermoviscous composite resin using two different preheating methods for the restoration of non-carious cervical lesions (NCCLs)., Material and Methods: A total of 120 NCCLs were randomized into two groups (n = 60 each). In one group, a bulk-fill thermoviscous composite resin (VisCalor bulk, Voco GmbH) was preheated using a dispenser heater (DH, VisCalor Caps dispenser/warmer), while in the other group, the same resin was preheated with a bench heater (BH, Caps Warmer). In the BH group, the composite underwent preheating at 68 °C using a heating bench for 3 min while in the DH group, the composite was preheated at the same temperature for 30 s using a dispenser heater. Subsequently, the preheated bulk-fill thermoviscous composite resin was directly applied to the NCCLs. The restorations were evaluated at baseline, and after 6, 12, 18, and 24 months of clinical service using the FDI criteria. The total working time was recorded. The study used TOST-P to assess groups equivalence, Kaplan-Meier analysis for retention/fracture rate, log-rank test for secondary outcomes' survival distributions, and paired t-tests for comparing time per clinical step between groups (α = 0.05)., Results: After 24 months, 106 restorations were evaluated. Four restorations were lost-two from the DH group and two from the BH group-resulting in similar retention rates for both groups (96.1%, 95% CI 86.8 - 98.9, p > 0.05). The hazard ratio was 0.83 (95% CI 0.26 to 2.72), indicating no significant difference between the groups (p > 0.05). All other FDI parameters were deemed clinically acceptable. However, the total working time for the BH group was significantly longer than that for the DH group (p < 0.001)., Conclusions: Both preheating protocols employed for the bulk-fill thermoviscous composite resin demonstrated high and equivalent survival rates after 24 months, the other FDI parameters were deemed clinically acceptable over the same period., Clinical Significance: Clinicians can choose either method for heating the thermoviscous composite resin for restoration of non-carious cervical lesions, as they do not impact important clinical outcomes after 24 months. The total working time for the bench heater is higher than that for the dispenser heater due to the need for preheating of the bench heater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the postoperative sensitivity (POS), as well as the clinical performance of posterior restorations using a new chemically-cured bulk-fill composite (Stela Automix and Stela Capsule, SDI) comparing with a light-cured bulk-fill composite after 6 months., Methods: Fifty-five participants with at least three posterior teeth needing restoration were recruited. A total of 165 restorations were performed on Class I or Class II cavities. After the application of Stela primer, the chemically-cured composite (Stela Automix or Stela Capsule) was inserted. For the light-cured composite group, a universal adhesive (Scotchbond Universal) was applied with a bulk-fill composite (Filtek One). Participants were evaluated for spontaneous and stimulated POS in the baseline, after 48 h, 7 days, and 6 months. Additionally, each restoration was assessed using the updated version of FDI criteria after 6 months. The differences in the proportions of the groups were compared by Cochran test statistics (α = 0.05)., Results: Both chemically-cured composites showed a lower risk of POS compared to the light-cured composite at baseline and up to 48 h (p < 0.04). A significantly lower surface luster and texture was observed for the Stela Capsule composite compared to the light-cured bulk-fill composite (baseline and 6 months; p = 0.03). A significant color mismatch was observed for the light-cured bulk-fill composite compared to the chemically-cured composites (baseline and 6 months; p = 0.03). No significant differences were observed in any other item evaluations (p > 0.05)., Conclusion: Chemically-cured composites exhibit lower postoperative sensitivity and less color mismatch compared to a light-cured bulk-fill composite after 6 months of clinical service., Clinical Significance: The chemically-cured composites appear to be an appealing option for restoring posterior teeth, as they exhibit lower postoperative sensitivity compared to a light-cured bulk-fill composite, both at baseline and up to 48 h, and less color mismatch., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: The aim of this study was to evaluate the effect of an adhesive loaded with 0.2 % copper (Cu) and 5 % zinc oxide (ZnO) nanoparticles (Nps) on its adhesive properties and enzymatic activity at the hybrid layer ex vivo in a randomized clinical model., Methods: Fifteen patients participated in this study, and a total of 30 third molars were used. Occlusal cavities (4 × 4 × 2 mm) were made in each tooth, and randomly divided into 2 groups: (i) Experimental group: commercial adhesive loaded with 0.2wt % CuNps and 5wt % ZnONps; and (ii) Control Group: non-loaded commercial adhesive. Teeth were restored with resin composite. Thirty days later, extractions were performed. Extracted teeth were longitudinally sectioned. Nps in powder were characterized by field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX) analysis. Microtensile bond strength (μTBS), degree of conversion (DC), and nanoleakeage (NL) tests were executed. In situ zymography (Zym) was performed to evaluate the gelatinolytic activity at the hybrid layer. Student's t-test (α = 0.05) was applied for all tests., Results: μTBS and DC did not show significant differences (p > 0.05) between both groups. However, NL and gelatinolytic activity at the hybrid layer showed significant values (p < 0.05) for experimental group in comparison with control group., Conclusion: The addition of 0.2 % CuNps and 5 % ZnONps to a universal adhesive decreases NL and gelatinolytic activity at the hybrid layer, without jeopardizing its adhesive properties., Significance: This randomized clinical trial with ex vivo analysis demonstrate that a commercial adhesive modified with 0.2wt % Cu and 5wt % ZnO Nps that does not affect its adhesive properties, reducing gelatinolytic activity and nanoleakage at the hybrid layer, which should contribute to an improvement of long term bonding-dentine clinical performance., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the influence of dentin moisture on the clinical behavior of a universal adhesive on posterior teeth after 36 months of follow-up., Methods: Forty-five patients participated in this study. Following a split-mouth design, three operators placed 90 Class I/Class II restorations over moist dentin (MD) or dry (DD) (n = 45) with resin composite (Filtek Bulk Fill) and a universal adhesive used in the etch-and-rinse mode (Single Bond Universal). Each restoration was evaluated according to the FDI and USPHS criteria (postoperative sensitivity, fracture and retention, marginal staining, marginal adaptation, and recurrence of caries) at baseline and after 6-, 12-, and 36 months. For statistical analysis, Kruskal Wallis analysis of variance rank (α = 0.05) and Kaplan-Meier survival analysis were used., Results: No significant difference between groups was observed in each FDI criterion after 36 months of clinical evaluation (p > 0.05). The retention rates (confidence interval 95 %) were 97.37 % (86.5 - 99.5) for both MD and DD without significant difference between them (p > 0.05). Eight restorations (MD = 4; DD = 4) showed minimal marginal staining defects (p > 0.05). Two restorations were lost (MD = 1; DD = 1). Fifteen restorations (MD = 8; DD = 7) presented minor marginal discrepancies according to the FDI criteria (p > 0.05)., Conclusion: The clinical performance of the universal adhesive when applied in etch-and-rinse mode was not influenced by dentin moisture in posterior bulk-fill composite restorations., Clinical Significance: The level of dentin moisture appears not to influence the clinical efficacy of a universal adhesive when applied using the etch-and-rinse technique in posterior composite resin restorations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: This 24-month, double-blind, split-mouth randomized clinical trial aimed to compare the retention rates of a preheated thermoviscous composite resin (PHT) compared to a non-heated composite resin (NHT) in non-carious cervical lesions (NCCLs)., Methods: A total of 120 restorations were restored on NCCLs using a preheated (VisCalor bulk, Voco GmbH) and a non-heated (Admira Fusion, Voco GmbH) composite resins with 60 restorations per group. A universal adhesive in the selective enamel conditioning was applied. In the PHT group, composite was heated at 68 °C for using a bench heater. In the NHT group, no heating was employed. Both restorative materials were dispensed into caps and inserted into the NCCLs. The restorations were evaluated at baseline, 6, 12, 18, and after 24 months of clinical service using the FDI criteria. Statistical analysis was performed with Kaplan-Meier estimation analysis for retention/fracture rate and Chi-square test for the other FDI parameters (α=0.05)., Results: After 24 months 108 restorations were assessed. Seven restorations were lost (two for PHT group and five for NHT group), and the retention rates (95 % confidence interval [CI]) were 96.7 % (81.5-99.9) for PHT group and 90.8 % (81.1-96.0) for NHT group, with no statistical differences between them (p > 0.05). The hazard ratio (95 % CI) was 0.52 (0.27 to 1.01), with no significant difference within groups. In terms of all other FDI parameters that were assessed, all restorations were deemed clinically acceptable., Conclusions: Both composites showed high rates of retention rates after 24 months., Clinical Significance: The clinical performance of the new preheated thermoviscous was found to be as good as the non-heated composite after 24-month of clinical evaluation in non-carious cervical lesions., Registration of Clinical Trials: RBR-6d6gxxz., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the effect of the different radiant exposures from a multipeak light curing unit on the physical and mechanical properties of flowable and high-viscosity bulk-fill resin-based composites (RBC)., Methods: Five flowable bulk-fill RBCs (Tetric N-Flow Bulk-fill, Ivoclar Vivadent; Filtek Bulk Fill Flow, 3M Oral Care; Opus Bulk Fill Flow APS, FGM; Admira Fusion x-base, Voco and; and SDR Plus Bulk Fill Flowable, Dentsply Sirona) and five high-viscosity bulk-fill RBCs (Tetric N-Ceram Bulk-fill, Ivoclar Vivadent; Filtek One Bulk Fill, 3M Oral Care; Opus Bulk Fill APS, FGM; Admira Fusion x-tra, Voco; and SonicFill 2, Kerr) were photo-cured using a VALO Cordless light (Ultradent) for 10, 20, and 40 seconds at an irradiance of 1200, 800, or 400 mW/cm2, resulting in the delivery of 4, 8, 12, 16, 24, 32, or 48 J/cm2. Post-gel shrinkage (Shr) was calculated using strain-gauge test. The degree of conversion (DC, %) was calculated using FTIR. Knoop hardness (KH, N/mm2) and elastic modulus (E, MPa) were measured at the top and bottom surfaces. Logarithmic regressions between the radiant exposures and mechanical properties were calculated. Radiodensity was calculated using digital radiographs. Data of Shr and radiodensity were analyzed using two-way analysis of variance (ANOVA), and the DC, KH, and E data were analyzed with two-way ANOVA using split-plot repeated measurement tests followed by the Tukey test (a = 0.05)., Results: Delivering higher radiant exposures produced higher Shr values (p<0.001) and higher DC values (R2=0.808-0.922; R2=0.648-0.914, p<0.001), KH (R2=0.707-0.952; R2=0.738-0.919; p<0.001), and E (R2=0.501-0.925; R2=0.823-0.919; p<0.001) values for the flowable and high-viscosity RBCs respectively. Lower KH, E and Shr were observed for the flowable bulk-fill RBCs. All bulk-fill RBCs had a radiopacity level greater than the 4-mm thick aluminum step wedge. The radiant exposure did not affect the radiopacity., Conclusion: The Shr, DC, KH, and E values were highly correlated to the radiant exposure delivered to the RBCs. The combination of the higher irradiance for longer exposure time that resulted in radiant exposure between 24 J/cm2 to 48 J/cm2 produced better results than delivering 400 mW/cm2 for 40 s (16 J/cm2), and 800 mW/cm2 for 20 seconds (16 J/cm2) or 1200 mW/cm2 for 10 seconds (12 J/cm2). All the bulk-fill RBCs were sufficiently radiopaque compared to 4 mm of aluminum., (©Operative Dentistry, 2024.)

Objectives: The aim of this study was to evaluate the clinical performance of surface sealants associated with a bulk-fill composite in posterior restorations after 4 years., Methods: A total of 174 posterior restorations were performed on 57 participants using a self-etch adhesive system and a bulk-fill composite. The groups were then divided into the following categories: 1) without surface sealant (NoS), 2) with surface sealant Biscover (Bisco, SBi), and 3) with surface sealant Permaseal (Ultradent, SPe). Restorations were evaluated using FDI criteria at baseline and after 1 and 4 years. Statistical analysis was conducted using Kaplan-Meier survival analysis and the Chi-square test (α = 0.05)., Results: After 4 years, only one restoration was lost (1 in the NoS group). The fracture/retention rate (with 95% confidence interval) was 98% for NoS and 100% for both SBi and SPe (p = 0.76). The majority of secondary outcomes showed minor defects, with no significant differences among the groups (p > 0.05). However, significant differences were observed among the groups in terms of marginal staining and marginal adaptation (p = 0.03). In both items, twelve restorations (nine in NoS, one in SBi, and two in SPe) showed minor marginal discrepancies favoring the sealant groups (SBi and SPe)., Significance: Regardless of the use of surface sealants, the bulk-fill composite restorations showed excellent clinical performance after 4 years. However, the groups that received sealants showed better marginal adaptation and less marginal discoloration compared to those that did not receive sealants., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: The objective of this double-blind, split-mouth, randomized clinical trial was to evaluate the color match of a single-shade composite resin Admira Fusion X-tra in comparison with a multi-shade composite resin Admira Fusion in non-carious cervical lesion restorations (NCCLs)., Methods and Materials: One hundred and twenty restorations were performed on NCCLs with two restorative materials (n=60). After prophylaxis, the teeth were isolated with a rubber dam, and one universal adhesive was applied in the selective enamel etching strategy. For both groups, the restorations were inserted incrementally and light-cured. The values of the coordinates L*, a*, and b* in the cervical third before vs after the restorations and cervical vs middle third after the restorations were evaluated using a digital spectrophotometer after the coordinate values were used to calculate the CIEDE (ΔE00). The restorations were evaluated at baseline and after 7 days of clinical performance according to the FDI criteria. Statistical analysis was performed using the Chi-square test for all parameters. Color change was analyzed by Student t-test for paired samples (α=0.05)., Results: All restorations were evaluated after 7 days. Regarding the color measurement, no significant difference was observed when Admira Fusion was compared to Admira Fusion X-tra for any of the comparisons performed (p>0.05). However, the values of ΔE00 in the cervical third before vs after the restorations were higher when compared with ΔE00 observed when the cervical vs middle third after restorations were compared. All restorations received the score "clinically very good" after 7 days for all outcomes, including the subjective color match, when evaluated for FDI criterion., Conclusions: The single-shade composite resin used achieves the same color match when compared to a multi-shade composite resin after 7 days in NCCLs., (©Operative Dentistry, 2024.)

Objectives: To evaluate the influence of a glutaraldehyde-based desensitizer (GL) on postoperative sensitivity (POS) in posterior bulk-fill resin composite restorations using an adhesive applied in the self-etch (SE) and etch-and-rinse (ER) strategies; and to assess the clinical performance of the restorations., Methods: Posterior resin composite restorations (n = 228) at least 3 mm deep were inserted in 57 subjects using a split-mouth design. The adhesive was applied with/without prior application of a GL. A resin composite was used for all restorations. Spontaneous POS (risk and intensity), as well as POS caused by stimulation with an air blast and assess the response to horizontal and vertical percussion was assessed using two scales in the baseline and after 7, 14, and 30 days. In addition, some parameters were evaluated using FDI criteria up to 24 months of clinical service., Results: No significant POS was observed (p > 0.05). A higher absolute risk and intensity of spontaneous POS was observed within 7 days (35.1%), without statistically significant differences among groups. At 24 months 5 restorations were considered clinically unsatisfactory, and 73 restorations showed minor discrepancies in adaptation, with no significant differences between groups (p > 0.05)., Significance: A GL agent does not influence POS in posterior restorations with bulk-fill resin composite. It may be considered a dispensable clinical step in the restorative protocol., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: A systematic review and a meta-analysis were performed to answer the following research question: Are there differences in the color match and surface texture of nanofilled/nanohybrid and hybrid composite in patients with direct posterior restorations?, Data: Randomized clinical trials that compared nanofilled/nanohybrid and hybrid composite in direct restoration in posterior teeth were included. For the analysis of the bias the risk of bias tool (RoB) was used. Meta-analyses of different pairs (nanofilled vs. hybrid and nanohybrid vs. hybrid composite) were conducted for surface texture and color match and other secondary outcomes at different follow-ups, using a random effects model. Heterogeneity was assessed with the Cochran Q test and I 2 statistics. GRADE was used to assess the quality of the evidence., Sources: A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and SIGLE, without restrictions. IADR abstracts (2001-2019), unpublished and ongoing trials registries, dissertations and theses were also searched., Study Selection: 28 studies remained. No study was considered to be at low RoB; four studies were judged to have high RoB, and the remaining were judged to have unclear RoB., Results: For the primary and secondary outcomes variables no significant differences were detected between nanofilled/nanohybrid restorations and hybrid composite restorations in any of the study follow-ups (p > 0.08). The body of evidence for surface texture and color match was classified as moderate or low., Conclusion: No evidence of difference was found between nanofilled/nanohybrid and hybrid composite in any of the clinical parameters evaluated., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objective: The aim of this double blind, randomized controlled trial was to evaluate the 36-month clinical performance of the layering technique (incremental [IF] vs. bulk-fill [BF]) in posterior composite resin restorations bonded with self-etch (SE) and etch-and-rinse (ER) strategies., Methods: Posterior dental cavities of 72 participants (n = 236), with a cavity depth of at least 3 mm, were randomly divided into four groups. The restorations were bonded using either the Tetric N-Bond ER or Tetric N-Bond SE. The composite resin Tetric N-Ceram Bulk-Fill was placed either IF or using BF. Two experienced and calibrated examiners evaluated the restorations using FDI criteria in the baseline and after 12, 24 and 36-month. The statistical analyses were performed using the Wilcoxon Signed rank test (α = 0.05) RESULTS: After 36-month, 14, 21 and 33 restorations showed minor fractures, marginal desadaptation and color mismatch, respectively (p > 0.05). Thirty-three restorations showed some marginal discoloration after 36-month with significant difference between ER (3 for ER-IF; 3 for ER-BF) and SE (14 for SE-IF; 12 for SE-BF; p < 0.05)., Conclusion: The BF technique showed excellent clinical performance, which was comparable during the 36-month of clinical evaluation with the 2-mm IF and it was not affected by the adhesive strategy. However, using the ER strategy reduces the risk of some marginal discoloration, irrespectively of the filling technique., Clinical Relevance: The bulk-fill material showed excellent clinical behavior when compared to its use in an incremental filling technique, mainly when associated to etch-and-rinse adhesive material after 3 years of clinical evaluation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: To compare the the loss of retention and color match of glass-ionomer cements (GIC) and resin-based composites (RC) in noncarious cervical lesions. Other secondary outcomes (surface texture, marginal adaptation, marginal discoloration, and secondary caries) were evaluated in a systematic review and meta-analysis., Materials and Methods: A comprehensive search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, and Cochrane. We included only randomized clinical trials. The quality of the evidence for each outcome was assessed using the GRADE tool., Results: A total of 1530 articles were identified, but only 19 reports remained for analysis, all of which were judged to possess "unclear" risk of bias. GIC showed higher retention rates in all follow-ups (1 to 3 years, p < 0.0001; at 5 years, p < 0.00001). No difference was observed for marginal discoloration, marginal adaptation and secondary caries in all follow-ups (p > 0.05). RC showed better color match than GIC only at 2 years (p = 0.03). Higher roughness was observed in GIC in all follow-ups (at 1 year p = 0.0003; at 3 years p = 0.0004). Quality of evidence was graded as moderate or low due to unclear risk of bias and imprecision in some outcomes., Conclusion: The loss of retention of RMGIC/GIC was inferior to that of RC, but a higher roughness was observed in the RMGIC/GIC when compared to RC in all follow-ups of the clinical studies evaluated. In addition, the color match was better with RC only in the 2-year follow-up when compared to GIC. The quality of evidence was judged as moderate to low in these two outcomes.

Purpose: This double blind, randomized clinical trial compared the postoperative sensitivity of the placement technique (incremental and bulk fill) in posterior composite resin restorations bonded with two different adhesive strategies (self-etch and etch-and-rinse)., Methods: Posterior dental cavities of 72 participants (n=236), with a cavity depth of at least 3 mm, were randomly divided into four groups. The restorations were bonded using either the etch-and-rinse Tetric N-Bond (Ivoclar Vivadent) or the self-etch Tetric N-Bond SE (Ivoclar Vivadent). The composite resin Tetric N-Ceram Bulk Fill (Ivoclar Vivadent) was placed either incrementally or using the bulk-fill technique. Two experienced and calibrated examiners evaluated the restorations using World Dental Federation criteria after one week of clinical service. Spontaneous postoperative sensitivity was assessed using a 0-4 numerical rating scale and a 0-10 and 0-100 visual analog scale up to 48 h after the restorative procedure and after one week., Results: The risk (p>0.49) and intensity of spontaneous postoperative sensitivity (p>0.38) was not affected by the adhesive strategy or the filling technique. The overall risk of postoperative sensitivity was 20.3% (95% confidence interval 15.7-25.9) and typically occurred within 48 hours after the restorative procedure., Conclusions: The overall risk of immediate postoperative sensitivity was 20.3% and was not affected by either the adhesive strategy (etch-and-rinse/self-etch) or the filling technique (incremental/ bulk).

Purpose: To evaluate the effect of an acid containing 2% chlorhexidine (Ac/CHX) or a 2% CHX aqueous solution (Aq/CHX) on the immediate and 5-year bonding properties of resin/dentin interfaces produced by two adhesives. The presence of CHX in these interfaces was also evaluated under micro-Raman spectroscopy., Materials and Methods: Forty-two molars were ground to expose a flat dentin surface. In the control group, the surfaces were etched with conventional phosphoric acid, and Prime&Bond NT (PB) and Adper Single Bond 2 (SB) were applied. In Ac/CHX, an acid containing 2% CHX was applied after adhesive application. In the Aq/CHX group, an aqueous solution of 2% CHX was applied for 60 s after etching. After placing the restoration, specimens were prepared and tested using the microtensile bond strength test (μTBS, 0.5 mm/min) immediately or after 5 years. For nanoleakage (NL), specimens at each period were immersed in silver nitrate solution and examined by EDX-SEM. In addition, specimens at each period underwent examination for CHX using micro-Raman spectroscopy. Data were submitted to appropriate statistical analysis (a=0.05)., Results: After 5 years, NL was more pronounced in the control than in the Ac/CHX or Aq/CHX (p<0.001). Significant reductions in the μTBS were observed for all groups; however, they were more pronounced for the control (p<0.001). CHX was still present in the hybrid layers Ac/CHX or Aq/CHX groups after 5 years., Conclusion: The use of a 2% chlorhexidine-containing acid or the application of an aqueous CHX primer may increase the long-term stability of resin/dentin interfaces.

Purpose: This study evaluated the effect of application technique and preparation size on the fracture strength (FS), microtensile bond strength (μTBS) and marginal integrity (MI) of direct resin composite restorations., Materials and Methods: Conservative (5 × 2 × 2 mm) or extended (5 × 4 × 2 mm) preparations below the cementoenamel junction were performed in 140 human maxillary premolars (n = 70 per group). After adhesive application (XP Bond), half of each group was restored with the bulk technique (one 4-mm increment of Surefill SDR Flow plus one 1-mm horizontal capping layer of TPH3 [Spectrum TPH3 resin composite]) and half incrementally (TPH3 in three horizontal incremental layers, 1.5 to 2 mm each), all using a metal matrix band. After storage (24 h at 37°C), the proximal surfaces of each tooth were polished with Sof-Lex disks. For FS measurement, 60 restorations were mounted in a universal testing machine and subjected to a compressive axial load applied parallel to the long axis of the tooth, running at a crosshead speed of 0.5 mm/min. For μTBS testing, 40 teeth were longitudinally sectioned to obtain resin-dentin bonded sticks from the cavity floor (bonded area: 0.8 mm2). Specimens were tested in tension at 0.5 mm/min. The external marginal integrity of both proximal surfaces was analyzed using SEM of epoxy resin replicas. The μTBS, marginal integrity, and fracture resistance data were subjected to two-way ANOVA, and Tukey's post-hoc test was used for pair-wise comparisons (a = 0.05)., Results: Fracture resistance, microtensile bond strength, and marginal integrity values were not statistically significantly affected by application technique or preparation size (p = 0.71, p = 0.82, and p = 0.77, respectively)., Conclusions: The use of a bulk-fill flowable composite associated with a conventional resin composite as a final capping layer did not jeopardize the fracture strength, bond strength to dentin, or marginal integrity of posterior restorations.

Objective: To test the influence of a hydrophobic resin coating (HC) on the immediate (24h) and 6-month (6m) microtensile dentin bond strengths (μTBS) and nanoleakage (NL) of three universal adhesives applied in self-etch (SE) or in etch-and-rinse (ER) mode., Methods: Sixty caries-free extracted third molars were assigned to 12 experimental groups resulting from the combination of the factors "adhesive system" (Scotchbond Universal Adhesive [SBU], 3M ESPE; All-Bond Universal [ABU], Bisco Inc.; and G-Bond Plus [GBP], GC Corporation); "adhesive strategy" (SE or ER); "hydrophobic resin coating" [HC] (with or without Heliobond, Ivoclar Vivadent); and "storage time" (24h or 6m). Specimens were prepared for μTBS testing - (24h) half of the beams were immediately tested under tension; and (6m) the other half was stored in distilled water (37°C) for 6m prior to testing. For each tooth, two beams were randomly selected for NL evaluation for both evaluation times. Data were analyzed for each adhesive system using three-way ANOVA and Tukey's post-hoc test (α=0.05)., Results: μTBS: (24h): In SE mode, HC resulted in statistically greater mean μTBS for all adhesives. (6m): When HC was not used the mean μTBS for SBU/ER, ABU/ER, GBP/ER and SBU/SE decreased significantly. NL: (24h): SBU/ER, ABU/ER and GBP/SE resulted in a significant reduction in NL when HC was applied. (6m): No significant reduction was observed for SBU/ER or for SBU/SE regardless of the use of HC., Significance: The application of a hydrophobic resin coating improved the 24h and the 6m performances of all three adhesives systems in SE mode., (Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Objective: To compare the 18-month retention rates of composite restorations in non-carious cervical lesions [NCCLs] bonded with a self-etch adhesive with and without preliminary conditioning with EDTA., Methods: Forty-eight patients with two similar-sized NCCL were selected and randomly allocated to one of two groups. Two calibrated operators placed 96 restorations with a one-step self-etch adhesive (Adper Easy One, 3M ESPE). Half of the restorations were placed according to the manufacturer's instructions while, for the other half, the surfaces of the lesions were conditioned with 17% EDTA for 2 min prior to adhesive application. Two blinded and independent examiners evaluated the restorations at baseline, 6, 12, and 18 months, according to the FDI criteria. The comparison between groups in each period was conducted with the Fisher's exact test, and the performance of each group at the different periods was evaluated by McNemar's test (α=0.05)., Results: After 18 months, significantly higher retention rates (95% CI) were observed for the EDTA group (95.5 [84.9-98.7]) than the control group (79.6% [65.5-88.9]) (p=0.02). Significant deterioration of the marginal adaptation and marginal discoloration were observed for both groups over the 18-month evaluation., Conclusions: The preliminary conditioning with EDTA before application of a one-step self-etch adhesive significantly improved the retention rates of composite restorations in cervical lesions., Clinical Significance: Conditioning with EDTA is an alternative that improves the 18-month retention rate of cervical restorations bonded with a self-etch adhesive., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objectives: To identify if enamel bevelling, compared to no treatment, improves the retention rates and marginal discolouration of cervical composite restorations in non-carious cervical lesions (NCCLs) of adult patients, through a systematic review of the literature and meta-analysis., Sources: MEDLINE, Scopus, Web of Science, LILACS, BBO Library, Cochrane Library and SIGLE were searched without restrictions, as well as the abstracts of the annual conference of the IADR and the trials registry. Dissertations and theses were searched using the ProQuest Dissertations and Periódicos Capes Theses databases., Study Selection: We included randomised clinical trials (RCTs) that compared the retention rates restorations in NCCLs placed with or without bevel with at least 1-year follow-up. The risk of bias tool of the Cochrane Collaboration was used for quality assessment., Data: After duplicate removal, 1356 articles were identified. After abstract screening, 14 studies remained and this number was reduced to four after examination of the full-texts. Only two were considered to have a 'low' risk of bias. The overall risk difference was 0.0 (95% CI -0.04 to 0.04) for the retention rate (p=0.91) and 0.05 (-0.02 to 0.13) for the marginal discolouration (p=0.17)., Conclusions: No superiority of bevelled restorations was observed in the short-term follow-up of 1-year, although this conclusion was based on only two RCTs. There is not enough evidence to support the bevelled technique over non-bevelled for NCCLs over longer periods of time. Better standardization and reporting of RCTs of enamel bevelling are necessary in longer-term follow-ups., Clinical Significance: The literature still lacks a body of evidence to support the benefits of enamel bevel over non-bevelled for longer-term follow-ups, and future randomised clinical trials with low risk of bias should be conducted., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Purpose: The objective of this study was to clinically evaluate sealed composite restorations after 10 years and compare their behavior with respect to controls., Methods and Materials: The cohort consisted of 20 patients aged 18 to 80 years with 80 composite restorations. All participants in the sealing and no-treatment groups presented with clinical features for the marginal adaptation that deviated from the ideal and were rated Bravo (United States Public Health Service criteria). Composites with Alfa values for the marginal adaptation were used as the positive control., Results: The marginal adaptation behavior was similar between the sealing and control (+) groups, with a high frequency of Bravo values in the 10th year (80% and 51%, respectively). Most of the no-treatment (-) group maintained the Bravo values (91%) for 10 years, although some restorations (9%) progressed to Charlie values. The anatomy parameter differed significantly between the first and 10th years, with deterioration in all three groups (p<0.05). The secondary caries parameter had a similar behavior in the three groups (p>0.05)., Conclusions: Sealing the margins of the composite resin restorations had no significant effect compared with the control groups, under the conditions of this study. Sealing the restorations substantially improved the marginal staining and marginal adaptation parameters, although by the tenth year they were similar to the group without intervention.

Objectives: To evaluate the effect of acid etching and application of a hydrophobic resin coat on the enamel/dentin bond strengths and degree of conversion (DC) within the hybrid layer of a universal adhesive system (G-Bond Plus [GB])., Methods: A total of 60 extracted third molars were divided into four groups for bond-strength testing, according to the adhesive strategy: GB applied as a one-step self-etch adhesive (1-stepSE); GB applied as in 1-stepSE followed by one coat of the hydrophobic resin Heliobond (2-stepSE); GB applied as a two-step etch-and-rinse adhesive (2-stepER); GB applied as in 2-stepER followed by one coat of the hydrophobic resin Heliobond (3-stepER). There were 40 teeth used for enamel microshear bond strength (μSBS) and DC; and 20 teeth used for dentin microtensile bond strength (μTBS) and DC. After restorations were constructed, specimens were stored in water (37°C/24 h) and then tested at 0.5 mm/min (μTBS) or 1.0 mm/min (μSBS). Enamel-resin and dentin-resin interfaces from each group were evaluated for DC using micro-Raman spectroscopy. Data were analyzed with two-way analysis of variance for each substrate and the Tukey test (α=0.05)., Results: For enamel, the use of a hydrophobic resin coat resulted in statistically significant higher mean enamel μSBS only for the ER strategy (3-stepER vs 2-stepER, p<0.0002). DC was significantly improved for the SE strategy (p<0.00002). For dentin, the use of a hydrophobic resin coat resulted in significantly higher dentin mean μTBS only for the SE strategy (2-stepSE vs 1-stepSE, p<0.0007). DC was significantly improved in groups 2-stepSE and 3-stepER when compared with 1-stepSE and 2-stepER, respectively (p<0.0009)., Conclusions: The use of a hydrophobic resin coat may be beneficial for the selective enamel etching technique, because it improves bond strengths to enamel when applied with the ER strategy and to dentin when used with the SE adhesion strategy. The application of a hydrophobic resin coat may improve DC in resin-dentin interfaces formed with either the SE or the ER strategy. On enamel, DC may benefit from the application of a hydrophobic resin coat over 1-stepSE adhesives.

Objectives: To 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., Methods: Sixty 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 (0.8mm(2)) 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)., Results: ABU 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., Conclusions: The 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., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objectives: This study aims to evaluate the effect of different application modes on the immediate and 6-month resin-dentin bond strength (μTBS) and nanoleakage in the hybrid and adhesive layers., Materials and Methods: Three 1-step self-etch adhesives (One Coat 7.0 (OC), Clearfil S(3) Bond (CS), and FuturaBond NR (FB)) were applied on a flat superficial dentin surface of 30 human molars under manual mode or sonic vibration at a frequency of 170 Hz (SV). Composite build-ups were constructed incrementally; specimens were sectioned to obtain resin-dentin sticks with cross-sectional area of 0.8 mm(2) and tested in tension (0.5 mm/min) immediately (IM) or after 6 months (6M) of water storage. Two bonded sticks, from each tooth at each storage time, were immersed in a silver nitrate solution, photo-developed, and analyzed under scanning electron microscopy. The amount of nanoleakage was measured using the ImageTool 3.0 software. Data, from each adhesive, were analyzed by two-way ANOVA and Tukey's test (α = 0.05)., Results: OC and CS showed higher μTBS and lower nanoleakage in the IM period when applied with SV groups. For FB, no significant difference was observed between the two modes of application. All materials showed lower nanoleakage in the SV groups. Higher nanoleakage was observed after 6M for OC and FB., Conclusions: The sonic application mode at an oscillating frequency of 170 Hz can improve the resin-dentin μTBS, reduce the nanoleakage, and retard the degradation of the resin-dentin μTBS of Clearfil S(3) Bond and One Coat 7.0 adhesives., Clinical Significance: Sonic application mode at an oscillating frequency of 170 Hz can be helpful and easy to use in dental practice to guaranty long-lasting restorations.

Purpose: To measure the microshear bond strengths (μSBS) of composite resin to the intaglio surface of prefabricated indirect veneers and analyze the FE-SEM ultramorphology of the pretreated intaglio surfaces as well as the fracture modes., Materials and Methods: Three veneer systems (veneer and respective luting material) were used in this study: two prefabricated veneer types, Cerinate One-hour (CER, DenMat) and Componeer (CMP, Coltene), and a laboratory- made veneer, IPS e.max Press (IPS, Ivoclar Vivadent) used as the control. For each group, 10 veneers were used. After delimitation of the bonding area with a double-faced adhesive tape, 0.8-mm-diameter cylinders of composite luting material were bonded to the pretreated intaglio surface. After polymerization, the specimens were fractured in shear mode using the wire-loop method in a universal testing machine. The pretreated intaglio surface of two extra veneers and four fractured specimens per group were morphologically characterized using FE-SEM., Results: CER resulted in statistically lower mean μSBS (7.1 ± 1.2 MPa) than the other two veneer systems, CMP (15.2 ± 2.5 MPa) and IPS (14.7 ± 1.7 MPa) at p < 0.0001. As seen with the FE-SEM, the intaglio surface of CMP did not display microretentive features, while multiple microretentions were observed in both CER and IPS after HF etching., Conclusion: Within the limitations of this in vitro study, the CMP and IPS veneer systems resulted in greater bond strengths than those of the CER veneer system.

Purpose: To evaluate the radiopacity, ultimate tensile strength (UTS), microhardness (KHN), degree of conversion (DC), water sorption (WS) and solubility (SL) of experimental adhesives., Materials and Methods: Five experimental adhesives with different concentrations of barium-borosilicate oxide microfillers [0% (R0), 30% (R30), 40% (R40), 50% (R50), 60% (R60)] were formulated based on the adhesive system Ambar (FGM). The adhesive Adper Single Bond 2 (SB, 3M ESPE) was used as commercial reference. For the radiopacity (n = 5), KHN (n = 5), WS (n = 10), and SL (n = 10) tests, adhesive disks were constructed (5.0 mm in diameter and 1.0 mm thick), while for UTS (n = 5), hourglass-shaped specimens with a cross-sectional area of 0.8 mm2 were used. The FTIR spectra of unpolymerized and polymerized adhesives were used to determine the DC. Data were submitted to a one-way ANOVA and Tukey's test (α = 0.05)., Results: All experimental adhesives showed radiopacity similar to enamel, except those of R0 and SB. Filler addition did not jeopardize the UTS, KHN, or WS of the filled adhesives in comparison with the unfilled version. Except for R40, filler addition reduced the SL. The filled adhesives showed lower DC when compared with R0, but the DC was similar or higher when compared with SB., Conclusions: The addition of barium-borosilicate glass up to 50% did not jeopardize the mechanical properties of the adhesive layer and seems to reduce its solubility.

Objectives: The aim of this study was to correlate the degree of conversion measured inside the hybrid layer (DC) with the microtensile resin-dentin bond strength (μTBS) and silver nitrate uptake or nanoleakage (SNU) for five simplified etch-and-rinse adhesive systems., Methods: Fifty-five caries free extracted molars were used in this study. Thirty teeth were used for μTBS/SNU [n=6] and 25 teeth for DC [n=5]. The dentin surfaces were bonded with the following adhesives: Adper Single Bond 2 (SB), Ambar (AB), XP Bond (XP), Tetric N-Bond (TE) and Stae (ST) followed by composite resin build-ups. For μTBS and SNU test, bonded teeth were sectioned in order to obtain stick-shaped specimens (0.8mm(2)), which were tested under tensile stress (0.5mm/min). Three bonded sticks, from each tooth, were not tested in tensile stress and they were immersed in 50% silver nitrate, photo-developed and analyzed by scanning electron microscopy. Longitudinal 1-mm thick sections were prepared for the teeth assigned for DC measurement and evaluated by micro-Raman spectroscopy., Results: ST showed lowest DC, μTBS, and higher SNU (p<0.05). All other adhesives showed similar DC, μTBS, and SNU (p>0.05), except for TE which showed an intermediate SNU level. The DC was positively correlated with μTBS and negatively correlated with SNU (p<0.05). SNU was also negatively correlated with μTBS (p<0.05)., Significance: The measurement of DC inside the hybrid layer can provide some information about bonding performance of adhesive systems since this property showed a good correlation with resin-dentin bond strength and SNU values., (Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

The purpose of this study was to evaluate in vitro the shear bond strength to enamel, flexural strength, flexural modulus, and contraction stress of one orthodontic composite and two flowable composites. Orthodontic brackets were bonded to 45 human maxillary premolars with the composites Transbond XT, Filtek Z-350 flow and Opallis flow and tested for shear bond strength. For measurement of flexural strength and flexural modulus, specimens were fabricated and tested under flexion. For the contraction stress test, cylindrical specimens were tested and an extensometer determined the height of the specimens. The data were subjected to one-way ANOVA and Tukey's test (α=0.05). The shear bond strength values were significantly lower (p<0.05) for the flowable composites compared with the orthodontic composite. For the flexural strength, no statistically significant difference was found among the composites (p>0.05) while the flexural modulus was significantly higher (p<0.05) for Transbond XT than for Filtek Z-350 flow and Opallis flow. The orthodontic composite presented significantly lower contraction stress values than the flowable composites (p<0.05). The light-activated orthodontic composite material presented higher flexural modulus and shear bond strength and lower contraction stress than both flowable composites.

Objective: To evaluate the surface treatment and hydrophilicity of the bonding agent on the composite repair strength (RS), silver nitrate uptake (SNU), surface roughness (SR) and estimation of surface area (SA)., Methods: Fifty resin blocks (Opallis, FGM) were polished and divided in 5 groups: no treatment (NT); roughening with a fine (FDB); medium (MDB); coarse-grit (CDB) and 50-μm aluminium oxide sandblasting (AO). A hydrophobic (Adhesive, Scotchbond Multi-Purpose Plus, 3M ESPE) or hydrophilic (Adper Single Bond 2, 3M ESPE) adhesive was applied, followed by composite placement (Opallis, FGM). Composite-composite bonded sticks (0.9 mm2) were tested in tension (1.0mm/min) immediately [IM] or after 6 months [6M] of water storage. Two sticks from each tooth, at each time, were immersed in a 50% silver nitrate solution and evaluated by SEM. A profilometer was used to measure SR. SEM images were used to estimate the SA using the Image J software. Data were analysed by ANOVA and Tukey's tests., Results: The AO showed the highest CR strength for both adhesives, whilst the NT group showed the lowest, irrespective of the storage period. The diamond burs had intermediate performance. Silver nitrate deposits were seen after 6M for the hydrophilic adhesive. The ranking of SR values (Ra) from the lowest to the highest was: NT

Background: Researchers conducting laboratory investigations have reported that bonding to dry demineralized dentin can be feasible technically as long as the adhesives are rubbed vigorously onto the dentin surface. The authors aimed to evaluate the 24-month clinical performance of resin-based composites in noncarious cervical lesions (NCCLs) in teeth restored with two etch-and-rinse adhesives that had been applied with a vigorous rubbing action to both dry and rewet dentin., Methods: The authors enrolled 40 patients in this study. They inserted 160 restorations and evaluated them at baseline and at six, 12 and 24 months of service. They divided the restorations into four groups: One-Step (OS) Universal Dental Adhesive System (Bisco, Schaumburg, Ill.) (acetone-based adhesive) with rewet dentin; OS with dry dentin; Adper Single Bond (SB) Plus Adhesive (3M ESPE, St. Paul, Minn.) (ethanol/water-based adhesive) with rewet dentin; and SB with dry dentin. The authors used the same resin-based composite for all restorations. They evaluated the restorations according to modified U.S. Public Health Service criteria., Results: The 24-month retention rates for the rewet and dry conditions, respectively, were 95.0 percent and 97.5 percent for SB and 97.5 percent and 91.9 percent for OS. The authors detected no significant difference between rewet and dry groups for either adhesive (P > .05). In terms of marginal discoloration, OS performed significantly worse than did SB, irrespective of dentin moisture (P > .05)., Conclusions and Clinical Implications: Dentin moisture seems not to be important for the retention of etch-and-rinse adhesives as long as the adhesives have been rubbed vigorously onto the dentin surface. The ethanol/water-based adhesive showed a better overall performance than did the acetone-based system.

Objective: This study evaluated the effect of 2% chlorhexidine-containing acid (Ac/CHX) and 2% chlorhexidine digluconate solution (CHX) on immediate (IM) and 2-year (2Y) resin-dentin bond strength (BS) and silver nitrate uptake (SNU) for two simplified etch-and-rinse adhesives., Methods: Forty-two caries-free extracted molars had a flat dentin surface exposed. In the control groups (groups 1), the surfaces were acid etched with conventional phosphoric acid and the adhesives Prime&Bond NT (PB) or Adper Single Bond 2 (SB) was applied after rinsing, drying and rewetting with water. In groups 2, Ac/CHX groups the adhesives were applied in a similar manner; however a 2% CHX-containing acid was previously applied. In groups 3, the adhesives were applied according to the control group; however the rewetting procedure was performed with an aqueous solution of 2% CHX for 60s. Composite build-ups were constructed incrementally and microtensile specimens (0.8mm(2)) were prepared for microtensile bond strength testing in the IM or 2Y periods at 0.5mm/min. For SNU, 2 bonded sticks from each tooth were coated with nail varnish, placed in the silver nitrate, polished down with SiC papers and analysed by EDX-SEM. The data from each adhesive was submitted to a two-way repeated measures ANOVA and Tukey's test (α=0.05)., Results: After 2Y, significant reductions of BS were observed for both adhesives in the control group (p<0.05). In Ac/CHX or CHX groups the BS remained stable for both systems. SNU was more evident in the control than in the experimental groups (p<0.05) both in IM and 2Y periods. The use of CHX in an aqueous solution or associated with the acid conditioner was effective to reduce the degradation of dentin bonds over a 2-year period., Significance: The addition of CHX digluconate in the acidic conditioner may be an excellent tool to increase the long-term stability of collagens fibrils within the hybrid layer against host-derived metalloproteinases without the need for additional steps for the bonding protocol., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Objectives: The aims of this study were to evaluate the effect of resin composite (Filtek Z250 and Filtek Flow Z350) and adhesive system [(Solobond Plus, Futurabond NR (VOCO) and Adper Single Bond (3M ESPE)] on the microtensile (μTBS) and microshear bond strength (μSBS) tests on enamel, and to correlate the bond strength means between them., Material and Methods: Thirty-six extracted human molars were sectioned to obtain two tooth halves: one for μTBS and the other one for μSBS. Adhesive systems and resin composites were applied to the enamel ground surfaces and light-cured. After storage (37(0)C/24 h) specimens were stressed (0.5 mm/min). Fracture modes were analyzed under scanning electron microscopy. The data were analyzed using two-way ANOVA and Tukey's test (α=0.05)., Results: The correlation between tests was estimated with Pearson's product-moment correlation statistics (α =0.05). For both tests only the main factor resin composite was statistically significant (p<0.05). The correlation test detected a positive (r=0.91) and significant (p=0.01) correlation between the tests., Conclusions: The results were more influenced by the resin type than by the adhesives. Both microbond tests seem to be positive and linearly correlated and can therefore lead to similar conclusions.

Objectives: This study evaluated the effect of composite pre-polymerization temperature and energy density on the marginal adaptation (MA), degree of conversion (DC), flexural strength (FS), and polymer cross-linking (PCL) of a resin composite (Filtek Z350, 3M/ESPE)., Methods: For MA, class V cavities (4 mm x 2 mm x 2 mm) were prepared in 40 bovine incisors. The adhesive system Adper Single Bond 2 (3M/ESPE) was applied. Before being placed in the cavities, the resin composite was either kept at room-temperature (25 degrees C) or previously pre-heated to 68 degrees C in the Calset device (AdDent Inc., Danbury, CT, USA). The composite was then light polymerized for 20 or 40s at 600 mW/cm(2) (12 or 24 J/cm(2), respectively). The percentage of gaps was analyzed by scanning electron microscopy, after sectioning the restorations and preparing epoxy resin replicas. DC (n=3) was obtained by FT-Raman spectroscopy on irradiated and non-irradiated composite surfaces. FS (n=10) was measured by the three-point-bending test. KHN (n=6) was measured after 24 h dry storage and again after immersion in 100% ethanol solution for 24h, to calculate PCL density. Data were analyzed by appropriate statistical analyses., Results: The pre-heated composite showed better MA than the room-temperature groups. A higher number of gaps were observed in the room-temperature groups, irrespective of the energy density, mainly in the axial wall (p<0.05). Composite pre-heating and energy density did not affect the DC, FS and PCL (p>0.05)., Significance: Pre-heating the composite prior to light polymerization similar in a clinical situation did not alter the mechanical properties and monomer conversion of the composite, but provided enhanced composite adaptation to cavity walls., (Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Purpose: This 24-month randomized paired tooth clinical study evaluated the performance of All Bond 3 used in the simplified (2-step) and full (3-step) versions., Methods: 33 patients, with at least two similar sized non-carious cervical lesions participated in this study. A total of 66 restorations were placed, half using the 2-step All Bond 3 (AB3-2) and the other half using 3-step All Bond 3 (AB3-3). The restorations were placed incrementally using the composite resin Aelite. The restorations were evaluated at baseline and after 6, 12 and 24 months following the modified USPHS criteria. Statistical differences between the adhesive were tested using with McNemar's test and clinical performance over time for each material with the Fisher's exact test (alpha = 0.05)., Results: After 24 months, six AB3-2 and four AB3-3 were rated as bravo for marginal discoloration but did not differ from each other significantly (P > 0.05). The retention rates at 24 months of AB3-2 and AB3-3 were 90.9% and 97.0%, respectively (P > 0.05).

Objective: To evaluate the performance of All Bond SE used in a one- or two-step protocol in a 24-month randomized clinical study., Methods: Thirty-three patients with two similarly sized non-carious cervical lesions participated in this study. A total of 66 restorations were placed, half using the one-step All Bond SE protocol (SE-1) and the other half using the two-step All Bond SE protocol (SE-2). The restorations were evaluated at baseline and after 6, 12 and 24 months following the modified USPHS criteria and analyzed by the McNemar's test and Fisher's exact test (alpha = 0.05)., Results: After 24 months, six SE-1 and four SE-2 restorations were rated as Bravo in marginal discoloration The retention rates for SE-1 and SE-2 were 84.8% and 90.9%, respectively, after 24 months. Compared to baseline, the retention rate for SE-1 was statistically lower., Conclusions: All Bond SE used in the one- or two-step protocol resulted in high retention rates after 24 months.

Objective: To evaluate the effects of surface treatment and intermediate agent hydrophilicity on durability of the composite repair by means of the microtensile bond strength test (microTBS) and silver nitrate uptake (SNU) and the effects of surface treatment on composite roughness (Ra) and micromorphological features (SEM)., Methods: Thirty resin composite blocks (4x6x6 mm) (Opallis, FGM) were polished after seven days and divided into three groups: no treatment (NT); roughening with a fine-grit diamond bur (DB); 50 microm aluminum oxide sandblasting (AO). A hydrophobic (Adhesive bottle, Scotchbond MultiPurpose [SBMP]) or hydrophilic adhesive (Adper Single Bond 2 [SB]) was then applied. The same composite was used for repair. Composite-composite bonded sticks (0.6 mm2) were tested immediately ([IM) or after six months (6 M) of water storage in tension (1.0 mm/minute). Two bonded sticks from each resin composite block were immersed in a 50% (w/v) solution of silver nitrate, photo-developed and analyzed by SEM. The composite specimens after surface treatments were analyzed with a contact profilometer (Ra) and SEM. Three-way repeated measures and one-way ANOVA were used to analyze data from the microTBS and Ra, respectively (alpha = 0.05)., Results: AO showed the highest composite repair strength (MPa) and Ra (microm) (52.7 +/- 6.4; 4.1 +/- 0.5), while the no treatment group (36.1 +/- 6.1; 0.57 +/- 0.5) showed the low est. DB (44.1 +/- 5.6; 1.5 +/- 0.2) had an intermediate performance. The Ra results were confirmed by SEM images. SNU was observed only in SB specimens after 6M for all groups., Conclusions: Aluminum oxide treatment provides the highest composite repair strength, regardless of the hydrophilicity of the intermediate agent and storage period. Early signs of degradation were detected for SB after six months as silver nitrate deposits within the adhesive layer.

This study evaluated the effect of a warm (W) or cold (C) air-dry stream for solvent evaporation on the immediate (IM) and six-month (6M) resin-dentin bond strength (microTBS) and silver nitrate uptake pattern (SNU) of two-step etch-and-rinse adhesive system (Adper Single Bond [SB] and Prime & Bond 2.1 [PB]). The adhesives were applied on demineralized dentin surfaces and a warm or cold air-dry stream (10 seconds) was applied followed by light-activation (10 seconds). After 24-hours of water storage, the specimens were serially sectioned in the "x" and "y" directions to obtain bonded sticks around 0.8 mm2 to be tested immediately or after six months of water storage. The specimens at each period were immersed in a 50% solution of silver nitrate, photodeveloped and analyzed by SEM for SNU. Higher IM microTBS values were observed for SB under W conditions. Both adhesives showed reductions in microTBS after 6M in both air temperatures. Regarding SEM, a low silver nitrate uptake was observed in the W groups either in IM or 6M for both adhesives.

Objectives: The purpose of this study was to evaluate the influence of water storage on resin-dentin bond strengths [microTBS] using different adhesive bonding approaches., Materials and Methods: Flat superficial dentin surfaces of 24 extracted human third molars were exposed and polished to create a standardized smear layer. The teeth were randomly distributed into four different groups: Three-step etch-and-rinse (Adper Scotchbond Multi-Purpose, 3M ESPE-SBMP), two-step etch-and-rinse (Adper Single Bond 2, 3 M ESPE-SB); two-step self-etch (AdheSE, Ivoclar/Vivadent-AD); and self-etch 1 step (Adper Prompt L-Pop, 3M ESPE-LP). Following the adhesive application (n = 6), resin composite was incrementally applied (Filtek Supreme XT-3 M ESPE) in order to obtain bonded sticks, with a cross-sectioned area of 0.81 mm2. The bonded sticks were randomly divided and assigned to be tested after one day [OD] (n 30) or six months [6 M] of water storage [6 M] (n = 30)., Results: Two-way ANOVA and Tukey's test showed that none of the adhesives showed degradation after 6 M. SB achieved the highest microTBS both in the [OD] (49.13 MPa) and [6M] (40.27 MPa). Despite the highest values in both time evaluations, the microTBS of SB significantly reduced after 6M. LP showed the lowest microTBS in both periods of evaluation (18.35 and 18.34 MPa)., Conclusions: Although a significant degradation was only observed for SB, this was the adhesive that showed the highest microTBS after 6 M of water storage.

Statement of the Problem: The performance of self-etch systems on enamel is controversial and seems to be dependent on the application technique and the enamel preparation., Purpose of the Study: To examine the effects of conditioning time and enamel surface preparation on bond strength and etching pattern of adhesive systems to enamel., Materials and Methods: Ninety-six teeth were divided into 16 conditions (N=6) in function of enamel preparation and conditioning time for bond strength test. The adhesive systems OptiBond FL (Kerr, Orange, CA, USA), OptiBond SOLO Plus (Kerr), Clearfil SE Bond (Kuraray, Osaka, Japan), and Adper Prompt L-Pop (3M ESPE, St. Paul, MN, USA) were applied on unground or ground enamel following the manufacturers' directions or doubling the conditioning time. Cylinders of Filtek Flow (0.5-mm height) were applied to each bonded enamel surface using a Tygon tube (0.7 mm in diameter; Saint-Gobain Corp., Aurora, OH, USA). After storage (24 h/37 degrees C), the specimens were subjected to shear force (0.5 mm/min). The data were treated by a three-way analysis of variance and Tukey's test (alpha=0.05). The failure modes of the debonded interfaces and the etching pattern of adhesives were observed using scanning electron microscopy., Results: Only the main factor "adhesive" was statistically significant (p<0.001). The lowest bond strength value was observed for OptiBond FL. The most defined etching pattern was observed for 35% phosphoric acid and for Adper Prompt L-Pop. Mixed failures were observed for all adhesives, but OptiBond FL showed cohesive failures in resin predominantly., Conclusions: The increase in the conditioning time as well as the enamel pretreatment did not provide an increase in the resin-enamel bond strength values for the studied adhesives., Clinical Significance: The surface enamel preparation and the conditioning time do not affect the performance of self-etch systems to enamel.

Objectives: To evaluate the influence of enamel border on regional resin-dentin microtensile bond strength (muTBS) over time., Methods: Thirty human third molars had a flat dentine surface exposed. Two adhesive systems (Single Bond [SB] and ScotchBond Multi Purpose Plus [SBMP]) were applied and composite resin crowns (Filtek Z250) were constructed. Teeth were divided into three groups (n=5). Group A, specimens were sectioned to obtain sticks to be tested in tension (0.5mm/min) immediately. Group B specimens were stored without outer enamel in water for 6 months, before sectioning and testing. Group C, specimens were stored with outer enamel in water for 6 months, before sectioning and testing. In all groups, the origin of the sticks, periphery and inner regions was controlled. The data for each adhesive were subjected to a two-way repeated measure ANOVA (location versus storage conditions) and Tukey's test., Results: No significant degradation in muTBS was observed for SBMU in all conditions. For SB, a significant reduction on muTBS was observed in the specimens without enamel border (group B). The degradation was more pronounced in the specimens from the periphery., Conclusions: The three-step etch-and-rinse system is less susceptible to water degradation effects; stable resin-dentin bonds can be achieved with two-step etch-and-rinse systems as long as there is a bonded enamel border.

This study evaluated the Vickers hardness (VHN) and diametral tensile strength (DTS) of the composite Z100 (3M ESPE) cured with: Quartz-Tungsten-Halogen light curing unit (QTH) (700mW/cm2- 40 s) and Argon laser (1,000mW/cm2- 10 s). Specimens of 2 mm depth and 8 mm diameter were immersed for 30 days at 37 degrees C in different storage means: water, alcohol, acetic acid, propionic acid and dry (control). The DTS (n = 8) was determined with a crosshead speed of 0.5 mm/min. The VHN (n = 8) test was carried out using a 50 g load for 60 s. Statistical analysis was performed by two-way ANOVA and Tukey's test (alpha = 0.05). The relationship between VHN and DTS was observed by Pearson correlation. The light source was not significant in both tests (VHN: P < 0.18; DTS: P < 0.92), but the factor storage showed significance (P < .001). Mechanical properties of the control group were statistically superior to those of the other storage groups (VHN = 102.2; DTS = 42.3 MPa). The alcohol group showed the lowest VHN (93.3) and DTS (33.8 MPa) values, which were similar to values for propionic (VHN = 97.5; DTS = 35.9 MPa) and acetic acids (VHN = 97.8; DTS = 36.1 MPa), but different from that of water (VHN = 102.2; DTS = 42.3 MPa). The relationship between VHN and DTS values presented a positive correlation (r2 = 0.90; P < 0.01).

A study was conducted to evaluate the top and bottom hardness of two composites cured using polymerizing units equipped with light-emitting diodes [LED] (LEDemetron; Elipar FreeLight, Coltolux LED) and one quartz-tungsten halogen device [QTH] (Optilux 501) under different exposure times (20, 40 and 60 sec). A matrix mold 5 mm in diameter and 2 mm in depth was made to obtain five disc-shaped specimens for each experimental group. The specimens were cured by one of the light-curing units (LCUs) for 20, 40 or 60 sec, and the hardness was measured with a Vickers hardness-measuring instrument (50 g/30 sec). Data were subjected to three-way ANOVA and Tukey's test (alpha = 0.05). LED LCUs were as effective as the QTH device for curing both composites. A significant increase in the microhardness values were observed for all light LCUs when the exposure time was changed from 20 sec to 40 sec. The Z250 composite showed hardness values that were usually higher than those of the Charisma composite under similar experimental conditions. LED LCUs are as efficient for curing composites as the QTH device as long as an exposure time of 40 sec or higher is employed. An exposure time of 40 sec is required to provide composites with a uniform and high Knoop hardness when LED light-curing units are employed.

Purpose: This paired-tooth randomized controlled prospective clinical study compared the clinical performance of three composite resins in Class III cavities after 12 months., Materials and Methods: Three materials were evaluated: a microfilled composite resin (Durafill VS), a hybrid composite resin (Filtek Z250), and a nanofilled composite resin (Filtek Supreme). Thirty-eight patients having at least three Class III restorations were enrolled in this study. A total of 114 restorations were placed by two calibrated operators according to the manufacturers' instructions. The adhesive system (Clearfil SE Bond) was either applied according to manufacturer's instructions (CSE non-etch) or enamel margins were first etched with phosphoric acid (CSE etch). One week later, the restorations were finished and polished. Two other independent examiners evaluated the restorations at baseline according to the USPHS criteria and USPHS modified criteria for the items color match and surface appearance. The restoration location was taken into consideration during the analysis of each item. A nonparametric analysis of variance (Friedman test) and the Wilcoxon test were used for statistical analysis (alpha = 0.05)., Results: The restoration location did not influence the evaluated items. Filtek Z250 showed the best color match at baseline, and after 6 and 12 months. No significant difference in the item surface appearance was detected at baseline; however, after 6 and 12 months, Filtek Z250 showed the worst performance on this item. No significant difference was found between CSE non-etch and CSE etch groups., Conclusion: The hybrid composite resin showed an excellent immediate and 12-month color match, which was superior to the nanofilled and microfilled composites tested. On the other hand, the nanofilled and microfilled composites showed the best surface appearance after 12 months. Additional etching of the enamel cavity margins did not influence the clinical performance of the adhesive Clearfil SE Bond.

Statement of the Problem: Eugenol is a radical scavenger that inhibits the polymerization of resin materials. Little is known about the effect of a eugenol-containing temporary restorative material on the resin-dentin bond strength of adhesive systems that partially dissolves and modifies the smear layer., Purpose of the Study: The aim of this study was to evaluate the effect of eugenol-containing temporary restoration (zinc oxide eugenol [ZOE]) on the resin-dentin microshear bond strength of etch-and-rinse and self-etch adhesives., Material and Methods: The roots of 18 human molars were removed and the crowns of the teeth were transversally sectioned into two halves. The dentin surfaces were embedded in acrylic resin. Half of the samples were stored while the remaining specimens were restored with eugenol-containing temporary restoration. After 24 hours, the ZOE restoration was mechanically removed and dentin surfaces were ultrasonically cleaned. Dentin surfaces were treated with one of the following adhesives: Single Bond, Clearfil SE, and iBond. Six cylinders of Z250 (0.5 mm high and 0.75 mm in diameter) were applied to each bonded dentin surface using a tygon tube. After storage for 24 hours, the specimens were subjected to micro-shear testing. The data was subjected to a two-way analysis of variance and Tukey's test (alpha=0.05)., Results: Similar bond strength values were obtained for Single Bond (p=0.48) either in the control or in the ZOE-treated group. For both self-etch systems, the bond strength in the ZOE-treated group was statistically lower than the control group (p < 0.01)., Conclusions: Although the prior use of eugenol-containing temporary restoration (IRM) affects the resin-dentin bond strength of the etch-and-rinse Single Bond, a more pronounced reduction on bond strength was observed for the two self-etch systems evaluated (iBond, Clearfil SE Bond). CLINICAL SIGNIFICANCE Eugenol-containing provisional restorations (IRM) should not be used prior to the placement of resin restorations bonded with the two-step etch-and-rinse Single Bond and the self-etch adhesives systems iBond and Clearfil SE Bond.

This study compared the clinical performance of a microhybrid resin composite to lined Class V restorations or to those restorations without a flowable resin composite over a 24-month period. Nineteen patients with at least 2 pairs of equivalent cervical erosion/attrition/abfraction lesions, under occlusion, were enrolled in this study. A total of 74 restorations were placed, half for each group (Single-Bond + Filtek-Flow + Filtek Z250 or Single-Bond + Filtek Z250). According to the manufacturers' instructions, 2 calibrated operators placed all restorations. Two other independent examiners evaluated the restorations at baseline and after 24 months, according to the USPHS criteria and modified criteria for color match. The classic alpha score was divided into A1 for "not detectable" and A2 for "slightly discernible" filling. Statistical analysis was conducted using Fisher's exact test (alpha=0.05). For each group, 8 restorations were lost after 24 months (retention rate of 89.2%). All the restorations showed a trend toward dark yellowing after 24 months (color match A2).

This study compared the clinical performance of a nanofilled resin composite for posterior restorations with 2 microhybrid and 1 packable composite after 12 months of clinical service. Forty-two patients with at least 5 Class I or II restorations under occlusion were enrolled in this study. A total of 148 restorations were placed, 25% for each material (Filtek Supreme, Pyramid, Esthet-X or Tetric Ceram). Two calibrated operators placed all restorations, according to the manufacturers' instructions. One week later, the restorations were finished/polished. Two independent examiners evaluated the restorations at baseline and after 12 months according to the USPHS modified criteria. All patients attended the 12-month recall and 148 restorations were evaluated. Friedman repeated measures analysis of variance by rank and Wilcoxon sign-ranked test for pair-wise comparison was used for data analysis (alpha=0.05). All materials showed only minor modifications, and no differences were detected between their performance at baseline and after 12 months. After 1 year, the nanofilled resin composite showed similar performance to the other packable and microhybrid resin composites.

This study evaluated the clinical performance of four packable resin composite restorative materials in posterior teeth (Class I and II) compared with one hybrid composite after 3 years. Eighty-four restorations were placed in 16 patients. The tested materials were: (i) Solitaire + Solid Bond; (ii) ALERT + Bond-1; (iii) Surefil + Prime & Bond NT; (iv) Filtek P60 + Single Bond and (v) TPH Spectrum + Prime & Bond 2.1. All restorations were made using rubber dam isolation, and the cavity design was restricted to the elimination of carious tissue. Deeper cavities were covered with calcium hydroxide and/or glass-ionomer cement. Each adhesive system and composite resin was placed according to the manufacturer's instructions. One week later, the restorations were finished/polished and evaluated according USPHS modified criteria. Fourteen patients attended the 3-year recall and 75 restorations were evaluated at that time based on the same evaluation criteria. Friedman repeated measures analysis of variance by rank and Wilcoxon sign-ranked test for pair-wise comparison was used for data analysis (alpha = 0.05). The analysis was performed only for the baseline and for the 3-year period. Solitaire showed some fractures at marginal ridges in 25% of the cases. Solitaire and ALERT showed some concerns related to colour match (43 and 77%, respectively) and surface texture (86 and 77%, respectively). TPH Spectrum showed a great percentage of colour mismatch after 3 years, around 50%. Surefil and Filtek P60 showed an excellent clinical performance after 3 years, similar to the hybrid resin tested, TPH Spectrum. Solitaire did not fulfil the ADA acceptance criteria for restorative materials and, therefore, is not recommended for use in posterior restorations.

Purpose: The aim of this study was to investigate the intra- and intertooth microtensile bond strength variability of two adhesive systems applied to dentin., Materials and Methods: Twenty human third molars were ground to expose a flat dentin surface. Two adhesive systems (Single Bond and One Step) were applied according to the manufacturers' instructions and composite resin crowns were constructed incrementally. After 24 h in distilled water at 37 degrees C, each tooth was longitudinally sectioned in both "x" and "y" directions under 300 rpm to obtain sticks with a cross-sectional area of 0.8 mm2. The sticks from each tooth were tested at a crosshead speed of 0.5 mm/min. The fracture pattern of each stick was microscopically analyzed after debonding (400X). A mixed model with adhesive as a fixed variable, tooth as a random variable, and bonded area included as a covariate, was employed for the data treatment. In this model, all observations have the same variance, which is the sum of two components: the variance of the random effect (intertooth) and the variance of the errors (intratooth)., Results: The intratooth variability was greater than the intertooth variability., Conclusion: The intratooth variability is higher than the intertooth variability. Sticks from the same tooth cannot be considered as an experimental unit, since it does not fulfill all ANOVA requirements.

Purpose: To evaluate the cumulative loss of mass of two-step solvent-based adhesives, examine the effect of prolonged application time on the resin-dentin microtensile bond strength (microTBS), and correlate the microTBS with the evaporation rate of adhesive systems., Materials and Methods: An ethanol/water based (Single Bond: SB) and an acetone-based system (One Step: OS) were employed. Approximately 16 microl of each product was transferred to a small glass container and placed in an analytical balance. The cumulative loss of mass (CLM) was determined in every minute for 5 min to the nearest 0.0001 mg and again after 20 min (n = 4). For the microTBS test, a flat superficial dentin surface was exposed in 24 human third molars by wet abrasion. The adhesives were applied to a delimited area of 52 mm2 on wet surfaces, for 40, 90, and 150 s. Four teeth were assigned to each experimental group. Composite crowns were constructed incrementally. After storage in water at 37 degrees C for 24 h, teeth were sectioned to obtain sticks with cross-sectional areas of 0.8 mm2 to be tested in tension (0.5 mm/min). The CLM (%) for both adhesives was compared using a Student-t test at each minute (alpha = 0.05). The microTBS values were analyzed by two-way ANOVA and Tukey's test (alpha = 0.05)., Results: The CLM for OS was higher than for SB during the first 5 min, but these values were only statistically different at minutes 3, 4, and 5 (p < 0.05). A CLM of approximately 50% was observed for both adhesive systems after 20 min. The factor application duration and the interaction between application duration and adhesive were significant (p < 0.05). The increase in the application duration led to an increase in microTBS for both systems; however, the differences were only statistically significant for OS over the 150 s period (p < 0.05). A strong correlation was found between the microTBS and the cumulative loss of mass of adhesives., Conclusion: Prolonged application times can increase the resin-dentin microTBS of two-step adhesive systems, but the application duration is dependent on the solvent present in the bonding system.

Objectives: Verify whether the dimension of a bonded specimen stored prior microtensile testing and its regional variation may affect the resin-dentin bond strength (BS) over time., Methods: Thirty human third molars had a flat dentin surface exposed and all peripheral enamel removed. Two adhesive systems (Single-Bond and One-Step) were applied and composite resin crowns (Z250) were constructed. Teeth were divided into three groups (n = 5). Group A specimens were sectioned to obtain sticks to be tested in tension (0.5 mm/min) immediately. Group B specimens were stored in water for 6 months, before sectioning and testing. Group C specimens were sectioned; the sticks were stored for 6 months and tested. In groups A and B, the origin of the sticks, periphery and inner regions was controlled. Bond strength (BS) was expressed as an index that considers cohesive failures and estimated values of premature debonded specimens. One-way ANOVA and Tukey's test (alpha = 0.05) were used to compare groups A, B and C, and a second analytical approach (A and B) employed a two-way ANOVA (time versus regional differences) for each adhesive system., Results: For Single-Bond (SB), the BS for specimens in group A was higher than for groups B and C. For One-Step (OS), the BS in group A was higher than for B, which was in turn higher than for C. In the second group approach, no difference was found when the test was performed immediately; however, after 6 months, the inner sticks from group B showed significantly higher BS., Significance: (1) The amount of decrease in BS is dependent on the specimen size; (2) the decrease in BS was greater for peripheral specimens than more centrally located specimens.

The aim of this study was to compare the clinical performance over 1 year of a microhybrid composite resin for class V restorations both lined and not lined with a flowable composite resin. Nineteen patients having at least two pairs of cervical noncarious lesions under occlusion were enrolled in this study. A total of 38 restorations were placed, half for each group (Single-Bond + Filtek-Flow + Filtek Z250, and Single-Bond + Filtek Z250). Two calibrated operators placed all restorations according to the manufacturers' instructions. Two other independent examiners evaluated the restorations at baseline and after a 12-month period according to the USPHS criteria and modified criteria for color match. The classic alpha score was divided into A1 for "not detectable" and A2 for "slightly discernible" filling. Statistical analysis was conducted using Fisher's exact test and McNemar's test (P=0.05). One restoration was lost after 12 months for each group (retention rate 95% for each group). After 12 months, 18 restorations showed a trend towards dark yellowing (color match A2). The use of Filtek Flow as a liner under Filtek Z250 restorations did not improve the clinical performance of class V restorations after 6 and 12 months of evaluation.

Purpose: The purpose of this study was to evaluate the influence of variations in light intensity versus exposure time, under the same energy density, on the marginal adaptation and hardness of resin composites restorations., Materials and Methods: The occlusal surfaces of 20 third molars were flattened with 180-grit SiC paper and a Class I cavity was prepared (4 mm wide, 4 mm long, and 2 mm deep). The specimens were randomly divided into four groups (n = 5 teeth). The adhesive system was applied according to the manufacturer's directions followed by one increment of Filtek Z250. The resin composite was light activated with 18 J/cm(2) according to one of the following light intensities/exposure times: group 1-100 mW/cm(2)/180 s; group 2-300 mW/cm(2)/60 s; group 3-600 mW/cm(2)/30 s; group 4-1,000 mW/cm(2)/18 s. After 24 hours, the restorations were longitudinally sectioned into two halves. Enamel, bottom, and total mean gap widths (in micrometers) were measured with a stereomicroscope (x200). After that, one of the sections was embedded in acrylic resin and polished up to 4,000-grit SiC for Knoop hardness number (KHN) measurements (100 g/15 s) at the top and bottom surfaces. The data from mean gap widths were analyzed by one-way analysis of variance (ANOVA). The KHN values (kg/mm(2)) were subjected to a two-way, repeated-measures ANOVA (a = .05). Tukey's test was used for pairwise comparisons., Results: No significant difference was observed between total and bottom mean gap widths among groups (p > .05). Group 1 showed lower enamel mean gap widths than did groups 3 and 4 (p < .05) but similar to those for group 2 (p > .05). The KHN at the top surface was higher than the bottom hardness (p < .05). For the bottom surface, all groups had similar KHN values (p > .05)., Conclusions: The variations in light intensity and exposure times allowed the achievement of adequate mechanical properties. The use of a low light intensity reduces only the enamel mean gap width but has no effect on the overall gap formation along the composite-tooth interface., Clinical Significance: As long as an adequate energy density is used to produce adequate mechanical properties in the resin composite, the use of a low light intensity for an increased time does not markedly improve marginal integrity.