ABSTRACT
AIM: The aim of this in vitro investigation was to assess the impact of various anti-oxidants namely 5% proanthocyanidin, 10% sodium ascorbate, 10% alpha tocopherol, and 10% green tea on the bond strength of resin-based composite on bleached enamel. MATERIALS AND METHODS: One hundred twenty human maxillary central incisors which were freshly extracted for periodontal reasons, having intact labial surface were us ed in this study. Specimens were randomly divided into six groups (n = 20). Group A: negative control-no bleaching treatment, group B-positive control -bleaching, group C-bleaching + 5% proanthocyanidins, group D-bleaching +10% green tea, group E - bleaching +10% alpha -tocopherol, group F-bleaching + 10% sodium ascorbate. Surfaces were etched followed by application of total-etch bonding system, and composite resin cylinders were bonded. Specimens were tested for shear bond strength using the universal testing machine. STATISTICAL ANALYSIS USED: The data obtained were subjected to ANOVA and post hoc Tukey's test for statistical analysis. RESULTS: After using bleaching agents and antioxidants for the different groups, Group A has the highest bond strength and group B has the lowest bond strength. Amongst the antioxidants group D showed significantly higher bond strength as compared group C, group E, and group F. CLINICAL SIGNIFICANCE: Use of antioxidants instantly following the bleaching procedure and before resin bonding reverses the compromised bond strength of composite resin on bleached enamel without sitting tight for a time of one day to one month. CONCLUSION: Bleaching of enamel reduced the shear bond strength. All the antioxidants used in this study increased the bond strength of bleached enamel. Among the antioxidant groups, green tea extract showed significantly higher bond strength compared to proanthocyanidin, tocopherol, and sodium ascorbate.
