Effect of Three Different Antioxidants on Shear Bond Strength of Composites To Bleached Enamel - An In Vitro Study

Abstract

ABSTRACT:Context: Bleaching can result in reduced bond strength of composite resin to enamel. To overcome this, bonding procedure should be delayed by a period of 24 hours to three weeks to regain the reduced shear bond strength due to bleaching. To avoid this waiting period various methods have been projected. Among all the methods, the antioxidant treatment has shown immediate improvement in shear bond strength values. Objective:The aim of this in vitro study was to evaluate and compare the effect of 10% Sodium ascorbate, 10% Pomegranate peel extract and 10% Grape seed extract on the bond strength of composite resin to bleached enamel. Materials and Methods: Forty flat enamel surfaces were prepared from freshly extracted human premolars using a low speed diamond saw. Then the specimens were divided into four random groups (n = 10). All the groups were treated with 30% H2O2. The specimens in Group I were bonded immediately after bleaching, whereas Group II, III and IV were treated with antioxidants Sodium ascorbate, Pomegranate peel extract and Grape seed extract respectively. After preparation, a standard shaped resin composite was applied to all specimens. The teeth were stored in deionized water for 24hrs at 37°C and a universal testing machine determined their shear bond strength. The data were evaluated using ANOVA and Tukey Post Hoc tests.Results: There was a statistically significant difference in the mean shear bond strength among all the groups (p < 0.001). 10% Grape seed extract showed significantly higher shear bond strength followed by 10% Pomegranate peel extract and 10% Sodium ascorbate. Conclusion:The use of antioxidant immediately after bleaching the enamel surface, completely neutralizes the deleterious effects of bleaching and increases the shear bond strength significantly. Among the antioxidants, 10% Grape seed extract application after bleaching showed better bond strength.

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

“…The use of antioxidants may reverse the inclusion of peroxide ions. This antioxidants usage has been supported by the study conducted by Dabas et al 20 About 10% sodium ascorbate subgroup IIA (176.37 ± 42.38) showed significantly highest bond strength in comparison to subgroup IA (113.32 ± 9.73), this result was similar to that of Murali Mohan et al 21 and Manoharan et al 4 No significant statistical difference between subgroup IIA (176.37 ± 42.38) and subgroup IB (204.47 ± 44.76) has been observed, this means the application of sodium ascorbate antioxidant within 24 hours effectively reverses the compromised bond strength as similar to that of delay in bonding procedure for 3 weeks; this result was identical to that of Subramonian et al 7 There was no significant statistical difference between subgroup IIA (176.37 ± 42.38) and IIB (161.20 ± 8.22), this implies that delaying restoration for 3 weeks after the antioxidant application was of no clinical significance, this result was in concurrence with Nair et al, where they achieved similar bond strength between immediate antioxidant application group and stored for 2 weeks group. 22 …”