Evaluation of shear bond strength on dry and moist dentin when treated with different desensitizing andadhesive systems

Objectives: This research was designed to investigate the effect of rewetting the dry dentin with two different desensitizing agents on the shear bond strength of resin composite to dentin. Material and methods: A total of 120 freshly extracted, sound human molars were used in this study. They were divided into three main equal groups (n=40) according to the type of solvent used either water/ethanol, ethanol or acetone based. Each group was further subdivided into four subgroups, 10 teeth each (n=10), according to the condition of dentin substrate, either dry, moist,rewetted by Seal and Protect or rewetted by VivaSens desensitizing agents (total subgroups were 12). A Flat dentin surface was prepared, different surface treatments previously described were applied. Composite was bonded to the treated surfaces and shear bond strength testing was done using universal testing machine. Results: For water/ethanol based adhesive (Adper Single Bond 2 ) , the highest mean shear bond strength value was recorded in case of dry dentin surface, dry dentin rewetted by Seal and Protect desensitizer, Moist dentin substrate, andthe specimens of dry dentin rewetted byVivaSens desensitizer showed the lowest shear bond strength value.For both ethanol based adhesive (Excite) and acetone based adhesive (Primeand Bond NT), the highest mean shear bond strength values were recorded in case of dry dentin rewetted with Seal and Protect desensitizer, moist dentin, dry dentin substrate, and the specimens of dry dentin rewetted with VivaSens desensitizer showed the lowest shear bond strength value. Conclusion: Seal and Protect desensitizing agent was effective as a rewetting agent and can render the bonding procedure asless technique sensitive. On the other hand, using VivaSens desensitizerreduced the effectiveness of dentin bonding agents to thedentin surface.