ABSTRACT
OBJECTIVE: The purpose of this study was to evaluate whether the bond strength of polycarbonate brackets can be increased through surface treatment. METHODS: One hundred polycarbonate brackets (Alice) were bonded to bovine incisors with light-cured adhesive. The bracket bases were treated with one of three methods; sandblasting, plastic conditioner application, and combined treatment with sandblasting and plastic conditioner. The brackets without any surface treatment served as the control. The shear bond strength was tested with a universal testing machine, and failure pattern was assessed with the adhesive remnant index. RESULTS: The shear bond strength in all experimental groups was higher than that of the control group (p < 0.001). The group treated with plastic conditioner after sandblasting showed statistically higher shear bond strength than the sandblasting only group (p < 0.05). The group treated with plastic conditioner after sandblasting showed higher shear bond strength than plastic conditioner only group, but the difference was not statistically significant. CONCLUSION: The above results suggest that the surface treatments of polycarbonate bracket is mandatory to improve bond strength, and the most effective method is an application of plastic conditioner after sandblasting.