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Objectives: The present study evaluated the influence of a flowable resin layer on bond strength between resin cement and a universal adhesive applied using an immediate dentin sealing (IDS) technique., Methods and Materials: Coronary portions of bovine teeth were randomly divided into six groups (n=15). In the IDS.U group, the exposed dentin was immediately sealed with the Single Bond Universal adhesive (3M ESPE) following the self-etching protocol. In the IDS.UF group, a layer of Filtek Z350 (3M ESPE) flow resin was applied over the universal adhesive. In the DDS (control) group, the dentin was kept "fresh" and delayed dentin sealing was performed. After 24 hours in distilled water at 37°C, dentin surfaces were treated with pumice, phosphoric acid, and the application of the universal adhesive in the IDS.U and IDS. UF groups. The DDS group was treated with pumice and the universal adhesive was applied. The samples received cylinders of resin cement Rely X Ultimate (3M ESPE) made with the aid of starch tubes of 0.96 mm in diameter and 2 mm in length. They were submitted to the microshear bond strength test (μSBS) at 0.5 mm/min, after 24 hours (T1) and 3 months (T2). The fracture areas were evaluated qualitatively using a DSM 300 microscope (KOZO) with 45× magnification and classified as: adhesive, cohesive in cement, cohesive in dentin, or mixed. Samples were analyzed by scanning electron microscopy (SEM). The data were compared statistically between groups using the Kruskal-Wallis test, and intra-groups using the Mann-Whitney test (α=0.05)., Results: There were no significant differences between groups for the bond strength values (p>0.05). The IDS.UF group showed higher values at 3 months, when compared to the values of 24 hours (p<0.001). All groups showed a predominance of adhesive fracture (86.7% to 100%). SEM showed dentinal tubules exposed in the IDS.U and DDS groups; in the IDS.UF group, the tubules were completely sealed., Conclusions: The flow resin can be used on the adhesive when using the IDS technique because it increased the bond strength values after 3 months and promoted effective sealing of the dentinal tubules., (©Operative Dentistry, 2022.)

Background: Multimode adhesives incorporate the versatility of adapting to various clinical situations by its capacity to be used in different protocols. This study aimed to evaluate the clinical behavior of composite resin direct restorations (Class I and II) performed with different universal dentin adhesive application protocols comparing adapted FDI and adapted USPHS criteria., Methods: The current study is a randomized, double-blind, split-mouth, and convenience sample controlled clinical trial. The participants (age ≥ 18 years) had restorative need of Class I and/or II due to the presence of carious lesions and/or unsatisfactory restorations in at least three dental elements. Each participant received three application protocols for Scotchbond Universal adhesive (3M ESPE), one in each tooth to be restored: ER = etch-and-rinse + adhesive (n = 50); SEE = selective enamel etch + adhesive (n = 50) and SE = self-etch adhesive (n = 50). All teeth were restored in a similar way using Filtek™ Supreme composite resin (3M ESPE). Restorations were evaluated using the adapted FDI and adapted USPHS criteria, at baseline after 7 to 21 (12.02 ± 5.68) days (T1; n = 50 per group) and after 12 to 20 (15.8 ± 2.7) months (T2; n = 46 per group) by two previously calibrated evaluators (Kappa > 0.80). The statistical tests were performed between groups (Friedman), intragroup (Wilcoxon), and between the criteria considering acceptable and not acceptable restorations (McNemar), α = 0.05., Results: A statistically significant difference was observed only for the property "superficial staining", between groups at T2 (p = 0.01) for ER (n = 13 with score 2 or more) and SEE (n = 3 with score 2 or more) and intragroup for ER (T1, n = 1 with score 2 or more; T2, n = 13 with score 2 or more, p = 0.001) and SE (T1, n = 0 with score 2 or more; T2, n = 8 with score 2 or more p = 0.007). For the other comparisons between groups, intragroup, and between the adapted FDI and adapted USPHS criteria, there were no statistically significant differences (p ≥ 0.05)., Conclusions: It can be concluded that the different application protocols of the universal adhesive resulted in clinically "acceptable" restorations after 15.8 ± 2.7 months of follow-up. Adapted FDI and adapted USPHS criteria provided similar results to each other., Trial Registration: Number in Brazilian Registry of Clinical Trials (ReBEC): RBR-9p3hdp. Registered 24 May 2015.

Objective: To evaluate the effect of instrumentation techniques, irrigant solutions and specimen aging on fiberglass posts bond strength to intraradicular dentine., Materials and Methods: A total of 120 bovine teeth were prepared and randomized into control and experimental groups resulting from three study factors (instrumentation techniques, irrigant solutions, specimen aging). Posts were cemented with RelyX U100. Samples were submitted to push-out test and failure mode was evaluated under a confocal microscope., Results: In specimens submitted to water artificial aging, nickel-titanium rotary instruments group presented higher bond strength values in apical third irrigated with NaOCl or chlorhexi-dine. Irrigation with NaOCl resulted in higher bond strength than ozonated water. Artificial aging resulted in significant bond strength increase. Adhesive cement-dentin failure was prevalent in all the groups., Conclusion: Root canal preparation with NiTi instruments associated with NaOCl irrigation and ethylenediaminetetra acetic acid (EDTA) increased bond strength of fiberglass posts cemented with self-adhesive resin cement to intraradicular dentine. Water artificial aging significantly increased post-Clinical significance: The understanding of factors that may influence the optimal bond between post-cement and cement-dentin are essential to the success of endodontically treated tooth restoration.

When ozone is used during caries treatment, bond strength can be compromised by the release of oxygen. The use of antioxidant agents neutralizes the free oxygen. The aim of this study was to evaluate the effects of ozone and sodium ascorbate on resin-dentin microtensile bond strength (μTBS). Forty human third molars were divided into four groups: Group 1, not treated with ozone; Group 2, ozone application followed by acid etching; Group 3, acid etching followed by ozone application; and Group 4, ozone and application of sodium ascorbate. Bonded beams (1.0 mm(2)) were tested under tension (0.5 mm min(-1)). The μTBS values were analyzed using one-way analysis of variance (ANOVA) and the Tukey test (p=0.05). All beams that fractured were analyzed under stereomicroscopy (40×). Group 1 had significantly higher μTBS values than Group 2 or 3. The μTBS values of Groups 1 and 4 were similar and higher than those of Group 2. The use of ozone in Group 2 resulted in lower values of μTBS in all conditions evaluated. The predominant failure mode was adhesive. The application of ozone decreased the μTBS of the dentin-composite resin interface. These values were reversed when compared with Groups 1 and 2 when sodium ascorbate was used.

Purpose: The objective of this in vitro study was to evaluate the bonding compatibility between different adhesives and a dual-cured resin cement, using a conventional tensile bond test., Materials and Methods: The adhesives used were: Prime & Bond (PB) (Dentsply) (PB), Scotchbond Multi Purpose (SB) (3M), and the activator Self Cure (SC) (Dentsply). The dual-curing resin cement used was Enforce (EF) (Dentsply). Six groups with five specimens in each were tested: G1: EF/PB/EF (light cured); G2: EF/SB/EF (light cured); G3: EF/PB+SC/EF (light cured); G4: EF/PB+SC/EF (only chemically cured); G5: EF/EF (light cured); G6: EF/EF (only chemically cured). The resin cement was applied in two stainless steel molds with a cone-shaped perforation measuring 4 mm in diameter and 1 mm in thickness, and the adhesive was applied between them. Ten minutes after specimens were cured, the tensile strength was measured in a universal testing machine at a crosshead speed of 0.5 mm/min., Results: The mean values (MPa) +/- SD obtained in each experimental group were: G1: 1.4 +/- 0.2; G2: 1.3 +/- 0.2; G3: 1.2 +/- 0.4; G4: 0.8 +/- 0.2; G5: 1.2 +/- 0.1; G6: 0.7 +/- 0.1. The results were statistically evaluated using nonparametric Kruskal-Wallis and Dunn tests (p < or = 0.05). Statistically significant differences among groups were found only between G1 and G4, and G1 and G6., Conclusion: There was no incompatibility among the different adhesives used with dual-cured resin cement. The lowest tensile bond strength values occurred in the absence of photoactivation.