Resin-dentin bonds of etch-and-rinse adhesives to alcohol-saturated acid-etched dentin

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.

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.

The SB control group showed significantly higher bond strength values than did SB used on ethanol saturated 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.

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.