Does the antioxidant treatment affect the shear bond strength of orthodontic brackets: An in vitro study

Objective: To determine the shear bond strength of orthodontic brackets after anti-oxidant treatment on previously bleached teeth. Method: The experimental in-vitro study was conducted in Saudi Arabiaat Qassim University, Al-Qassim, and King Saud University, Riyadh, from December 2016 to March 2017, and comprised extracted maxillary and mandibular premolars which were divided randomly into three groups. In Group A, which was the control group, the teeth were etched and bonded, while those in Group B were bleached, etched and bonded. Group C was subjected to bleaching, followed by treatment with anti-oxidant 10% sodium ascorbate solution, then etched and bonded. All three groups were then tested and analysed for bond strength using the Instron, Universal testing machine. SPSS 23 was used for data analysis. Results: There were 60 teeth with 20(33.3%) in each of the three groups. Group C had the maximum mean shear bond strength of 12.231 +/- 2.1Mpa, followed by Group A with 10.948+/-2.1Mpa and Group B with 7.621 +/- 1.8Mpa. Conclusion: Anti-oxidant treatment had a positive effect on the shear bond strength of orthodontic brackets after tooth bleaching.