Comparative evaluation of the postbleaching application of sodium ascorbate, alpha-tocopherol, and quercetin on shear bond strength of composite resin to enamel.

Objective: This study aimed to evaluate and compare the impacts of the postbleaching application of sodium ascorbate, alpha-tocopherol, and quercetin on the shear bond strength (SBS) of composite resin.

Material And Methods: 60 extracted intact maxillary first premolars were collected and were randomly divided into five experimental groups as follows (n=12): Group A (negative control): no bleaching, Group B (positive control): bleaching with 40% hydrogen peroxide (HP), Group C: HP±10% sodium ascorbate for 10min, Group D: HP±10% alpha-tocopherol for 10min, and Group E: HP±1% quercetin for 10min. Composite bonding was done immediately after bleaching for Groups B-E and without any treatment for Group A.