The Effect of Aloe Vera, Pomegranate Peel, Grape Seed Extract, Green Tea, and Sodium Ascorbate as Antioxidants on the Shear Bond Strength of Composite Resin to Home-bleached Enamel

STATEMENT OF THE PROBLEM: Immediate application of bonding agent to home- bleached enamel leads to significant reduction in the shear bond strength of composite resin due to the residual oxygen. Different antioxidant agents may overcome this problem. PURPOSE: This study aimed to assess the effect of different antioxidants on the shear bond strength of composite resin to home-bleached. MATERIALS AND METHOD: Sixty extracted intact human incisors were embedded in cylindrical acrylic resin blocks (2.5×1.5 cm), with the coronal portion left out of the block. After bleaching the labial enamel surface with 15% carbamide peroxide, they were randomly divided into 6 groups (n=10). Before performing composite resin restoration by using a cylindrical Teflon mold (5×2 mm), each group was treated with one of the following antioxidants: 10% sodium ascorbate solution, 10% pomegranate peel solution, 10% grape seed extract, 5% green tea extract, and aloe vera leaf gel. One group was left untreated as the control. The shear bond strength of samples was tested under a universal testing machine (ZwickRoell Z020). The shear bond strength data were analyzed by one-way ANOVA and post hoc Tukey tests (p< 0.05). RESULTS: No significant difference existed between the control and experimental groups. Moreover, there was no statistically significant difference between the effects of different antioxidants on the shear bond strength of bleached enamel. CONCLUSION: Different antioxidants used in this study had the same effect on the shear bond strength of home-bleached enamel, and none of them caused a statistically significant increase in its value.