Comparative Evaluation of Effect of Different Antioxidants on Shear Bond Strength of Composites on Bleached Enamel: An In Vitro Study

Abstract

Aim: To evaluate the effect of antioxidants on the shear bond strength of composite resin to bleached enamel. Materials and methods: A total of 120 extracted permanent anterior teeth were split into four major groups, one among them being a control group. Group I (bleaching + without antioxidant), group II (bleaching + 10% sodium ascorbate), group III (bleaching + 5% grape seed extract), and group IV (bleaching + 5% pine bark extract). All of the groups were bleached using a gel containing 35% carbamide peroxide, and then they were divided into two subgroups depending on when the bonding operation was to be completed—subgroup A was done in 24 hours, while subgroup B took 3 weeks. The universal testing machine was used to measure the shear bond strength. Results: Subgroup IA showed poor shear bond strength than other groups, there was no statistically significant difference between subgroup IB, IIA, and IVA. Subgroup IIIA showed the highest shear bond strength than the remaining groups. Between subgroups IIA and IIB, IIIA and IIIB, and IVA and IVB there was no statistically significant difference. This shows that delaying the bonding procedure for 3 weeks shows similar shear bond strength when compared to groups that were immediately bonded after antioxidant applying groups. Conclusion: All the antioxidants’ immediate application could reverse compromised bond strength. Among them, 5% grape seed extract shows the highest increase in shear bond strength.