RESUMO
Objective To explore the best parameters of impulse Nd:YAG laser-aided debonding for ceramic bracket.Methods The removal of ceramic bracket from enamel surface by laser irradiation was investigated in vitro.Fifty-four premolars were used to test the tensile strength and 32 premolars for pulp cavity temperature test.The results were compared according to the laser setting(output power:0,2,3,5 W;time:2,4 s),the average force(830.3,556.5 g) necessary to break the adhesion between ceramic bracket and tooth,the different edible pigment on bracket surface(black or not).Results The bonding strength of ceramic bracket was significantly reduced by laser irradiation,averagely by 48%.The average bonding strenth in the six groups for tensile strength test was of statistical difference(P