ObjectiveTo evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols.Material and MethodsDeciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 μm, 50 μm, and 100 μm from the eroded surface and at 25 μm, 75 μm, and 125 μm from the enamel bond interface.ResultsRegarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05).ConclusionsWe did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).
Objective: The incorporation of thiourethane prepolymer (TU) into either the organic phase or as a surface treatment for filler particles in composites reduces polymerization stress and improves fracture toughness. The...
Objective: This randomized clinical trial evaluated the behavior of restorations with flowable bulk-fill resin composite in posterior teeth three years after the restorative treatment. Methods: Seventeen patients (12 women, 5 men, age 23-59) were selected to have at least two failing amalgam or resin restorations replaced and/or to have a carious lesion restored. The cavities were randomly allocated to receive either the flowable bulk-fill composite Surefil SDR Flow occlusally covered with the conventional nano-hybrid composite Esthet-X HD (bulk and body technique) or filled exclusively with Esthet-X HD placed in 2 mm increments (incremental technique). A two-step etch-and-rinse adhesive was applied in all cavities. Thirty-four Class I or II restorations were performed in posterior teeth (n=17) during baseline. After 03 years, modified USPHS and FDI criteria were used to evaluate the restorations. Data were subjected to Mann-Whitney statistical analysis (p0.05). No restoration failures were observed over time. Conclusion: After 03 years of clinical service, all restorations using a flowable bulk-fill composite in posterior teeth showed an acceptable performance. Clinical Significance: The overall quality of posterior restorations made with the bulk and body technique was similar to that of restorations made with a nano-hybrid composite incrementally placed.
AIM: The objective of this study was to evaluate the use of MMPs inhibitors (chlorhexidine and EDTA) in bond strength and quality of the hybrid layer of adhesive restorations in normal dentin using two ethanol-based total-etch adhesive systems. MATERIAL AND METHODS: Thirty-two extracted human molars were coronally sectioned and randomly divided into 8 groups (n=4), depending on the surface pre-treatment and adhesive system used. The total-etch adhesive systems Single Bond 2 (2-step) and Adper Scotchbond Multi-Purpose Plus (3-step) were used as follows: 1) according to manufacturer's instructions (etching with 37% phosphoric acid (H3PO4) for 15 s); 2) etching with H3PO4 for 15 s, followed by 2% chlorhexidine for 120 s; 3) etching with 0.1 M EDTA for 60 s; 4) etching with 0.1 M EDTA followed by 2% chlorhexidine for 120 s. Teeth were incrementally restored with composite resin (Filtek Z350XT). After water storage for 24 h, teeth were double-sectioned, yielding stick specimens of 1.0 mm² bonded area, and then subjected to microtensile bond strength (MTBS) test at 0.5 mm/min. Additional specimens were gold-sputtered to be analyzed under scanning electron microscopy (SEM). Data (in Mega Pascal) were subjected to Kruskal-Wallis and Dunn (p <0.05) tests. RESULTS: The etching protocol (37% H3PO4 or EDTA) interfered with hybrid layer formation, monomer penetration and the MTBS. Funnel shaped resin tags were observed when dentin was etched with 37% H3PO4. In these specimens, MTBS were also higher. EDTA conditioning produced thin hybrid layers and smaller MTBS, regardless the adhesive system used. Chlorhexidine application after conditioning resulted in no apparent differences between both evaluated techniques (37% H3PO4 or EDTA). CONCLUSION: The use of chlorhexidine as a MMP inhibitor does not alter immediate bond strength values and does not interfere with hybrid layer formation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.