Comparison of shear bond strengths of ceramic brackets after different time lags between lasing and debonding.

Laser use is effective in the debonding of ceramic brackets. However, a standardization of the laser debonding techniques used has not yet been implemented. The purpose of this study was to evaluate the effect of the time lag elapsed between lasing and shearing on debonding of ceramic brackets. One hundred polycrystalline ceramic brackets were placed on human premolar teeth, which were randomly divided into five groups of 20. One group was assigned as the control. The Er-YAG laser was applied on each bracket in four experimental groups at 5 W for 6 s with the scanning method. Debonding was performed 1 s, 18 s, 30 s, or 60 s after laser exposure. Shear bond strengths and adhesive remnant index scores were measured. Statistically significant difference was observed between the control and experimental groups when the data for the shear bond strengths was considered (p < 0.05). Adhesive remnant index scores of the groups were not statistically different (p > 0.05). Debonding ceramic brackets after 18 s when lased 6 s using an Er-YAG laser with the scanning method is safe and also suitable for clinical use since three brackets can be debonded at a time in succession.