Resin-Dentin Bonds of Etch-and-Rinse Adhesives to Alcohol-saturated Acid-etched Dentin

Purpose: To evaluate the effect of the alcohol wet-bonding technique on bond performance of the adhesive interface produced by two-step etch-and-rinse adhesive systems. Materials and Methods: Composite buildups were bonded to sectioned human third molars using Adper Single Bond 2 (SB) bonded to acid-etched dentin saturated with water (control) or ethanol, or XP Bond (XP) bonded to acid-etched dentin saturated with water (control) or tert-butanol. A simplified dentin dehydration protocol was performed using 100% ethanol or 99.5% tert-butanol directly applied to dentin for 60 s. Specimens were cut into nontrimming dentin-composite beams that were divided equally in two subgroups: immediately tested and after immersion in 10% NaOCl solution for 1 h. Specimens were tested in tension at a crosshead speed of 1 mm/ min until failure, and the failure mode was evaluated. Data were statistically analyzed with three-way ANOVA and Tukey's test (α = 0.05). Additional dentin disks were bonded using the same groups tested and examined for leakage under light microscopy after immersion in ammoniacal silver nitrate solution. Results: The SB control group showed significantly higher bond strength values than did SB used on ethanolsaturated dentin (p 0.05); this tendency was confirmed by the silver nitrate deposition. The use of tert-butanol did not influence XP bond strength values (p > 0.05) or silver nitrate penetration. NaOCl solution significantly reduced the bond strength of all groups tested (p 0.05) and also increased the interfacial silver nitrate penetration. Conclusion: The simplified alcohol wet-bonding technique used in the present study was not able to improve resin/dentin bond performance for simplified etch-and-rinse adhesive systems. Parole chiave: bond strength, ethanol wet-bonding, solvent, dentin