Study of the shear bond strength of five one-component adhesives under simulated pulpal pressure

Recently, several adhesive systems have been introduced that combine the primer and bonding resin in a single bottle. The purpose of this study was to evaluate the bonding efficiency of these one-component adhesives under conditions of simulated pulpal pressure and to determine the influence of storage time on the shear bond strength. One hundred caries-free human molars were embedded with epoxy resin in cylindrical rubber molds. Flat dentin surfaces at a level 1 mm above the pulpal chamber were obtained and used as the region for bonding. The specimens were randomly assigned to five groups (n = 20): (1) Syntac Single, (2) Prime & Bond 2.0, (3) One Step, (4) Single Bond, and (5) OptiBond Solo. Each bonding system was combined with the same composite resin (Herculite XRV). After resin polymerization, half of the samples from each group were tested at 1 week and the other half at 4 weeks. During the bonding procedure and storage time a pulpal pressure of 20 cm of serum was applied. Analysis of the data by one-way ANOVA testing showed that the shear bond strengths were significantly different (P < 0.001). OptiBond Solo and Single Bond presented the best results. As the storage time increased there was a significant decrease in the shear bond strength for all the adhesive systems used.