Evaluation of the effects of ultrasonic device and sandblasting techniques on shear bond strength of brackets with different base designs

Aim: The aim of this study was to evaluate the 1st and 2nd shear bond strength of laser, photo-etched and micro-etched base brackets using sandblasting and ultrasonic methods. Material and Method: In our study, 3 main groups were obtained using 102 brackets. 34 Equilibrium 2 brackets with laser bases, 34 Mini Master brackets with photo etched bases and 34 Miniature Twin brackets with micro etched bases were used. The 1st shear bond strength and 1st ARI scores of the brackets were evaluated. Then 3 main groups were divided into 2 subgroups and 6 groups were obtained with 17 samples in each group. Bracket bases were cleaned using sandblasting or ultrasonic methods and brackets were rebonded to the same teeth. Then 2nd shear bond strength and ARI scores were evaluated. Results: The 1st shear bond strength of the laser group is higher than the photo and micro-etched groups (p<0.05). The 2nd shear bond strength of laser sandblasting group is higher than the laser, photo-etched and micro-etched ultrasonic groups (p<0.05). The difference between 1st and 2nd shear bond strength is higher in all groups except for the photo-etched sandblasting group (p<0.05). There is significant difference between the groups in terms of 1st and 2nd ARI scores (p<0.05). Conclusion: It was observed that ultrasonic and sandblasting methods applied prior to the rebonding of the brackets had positive effects on cleaning of the bracket base. Adequate bond strength has been achieved in rebonded laser, photo-etched and micro-etched base brackets. Key Words: Bracket base design, sandblasting, shear bond strength, ultrasonic