Improving shear bond strength of metallic brackets after whitening

Admin Dental Press

Edition V25N5 | Year 2020 | Editorial Original Article | Pages 38 to 43

Juan Fernando Aristizábal, Angela Patricia Polanía González, James A. McNamara

Orthodontics. Tooth bleaching. Shear bond strength. Hydrogen peroxide. Sodium ascorbate

Objective: To evaluate a protocol for bonding metallic brackets after bleaching with hydrogen peroxide (HP). Methods: 60 extracted maxillary premolar were randomly divided into an unbleached control group and two groups bleached with a solution of 35% hydrogen peroxide prior to bonding. The teeth in one of the treated groups were bonded immediately after bleaching; while the other group was treated with 10% sodium ascorbate immediately after bleaching and before bonding. The teeth in all groups were stored in an artificial saliva solution for 7 days after bonding. The shear bond strength data was measured in megapascals (MPa) and the fail attempts were verified. The significance level was established at p<0.05. Results: The unbleached group, in which brackets were bonded to untreated enamel, had the highest bond strength values (11.0±5.7MPa) in comparison to the bleached group (7.14±40MPa), in which brackets were bonded to recently bleached enamel. Slightly improved bond strength was observed in the antioxidant group (8.13±5.4MPa), in which the teeth were bleached and then the antioxidant was applied to the teeth before bonding. Unbleached and bleached groups showed statistically significant difference for shear bond strength (p=0.03) and load strength (p=0.03); no significant differences were noted between unbleached and antioxidant groups (p=0.52). Conclusion: The antioxidant treatment applied immediately after bleaching was effective in reversing the reduction in shear bond strength of brackets after tooth bleaching.

Aristizábal JF, González APP, McNamara JA. Improving shear bond strength of metallic brackets after whitening. Dental Press J Orthod. 2020 Sept-Oct;25(5):38-43.

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