OBJECTIVETo study the best parameter of impulse Nd:YAG Laser-aided debracket.

METHODSTo measure the bonding strength of ceramic bracket and pulp cavity temperature after different laser energy. First group was not irradiated by laser, second group was irradiated by laser of power 5 W and irradiating duration 2 s, third group was power 3 W and duration 3 s, and fourth group was power 2 W and duration 5 s.

RESULTSThere were significant differences of bonding strength among the four groups. The bonding strength of ceramic bracket was significantly reduced by laser irradiating. There were significant differences of the pulp cavity temperature increasing among different laser power irradiating groups. The lowest temperature increasing (3.65 degrees C) group was the group of laser power 3 W and irradiating duration 3 s.

CONCLUSIONThe bonding strength of ceramic brackets was statistically reduced after laser irradiation and the best parameter of impulse Nd:YAG Laser-aided debracket is laser power 3 W and irradiating duration 3 s.