The effect of dentin surface moisture on bond strength to dentin bonding agents

This in vitro study compares the mean shear bond strengths of two dentin bonding agents to dry and to moist human dentin. The occlusal surfaces of 60 extracted human molars were ground to produce flat dentin surfaces. The teeth were divided into four groups of 15 specimens each. For Scotchbond Multi-Purpose dentin bonding agent, the teeth were etched, rinsed, and then either blotted with gauze, which left the dentin moist, or dried with compressed air. The primer and adhesive were then applied, and composite cylinders were bonded to the teeth. For Optibond, the teeth were again either blotted with gauze or dried with air. The primer and dual-activated adhesive were applied, and composite cylinders were bonded to the teeth. After storage in room-temperature distilled water for 48 hours, the specimens were thermocycled. Shear bond strength testing was performed at 1 week. Analysis using two-sample t-tests found no significant difference for either product in bond strengths to moist and to dry dentin (P > 0.05). This study indicated that for some current-generation dentin bonding agents, the presence of moisture on dentin surfaces does not compromise short-term bond strength.