Comparisons of different debonding techniques for ceramic brackets: an in vitro study. Part II. Findings and clinical implications.

A series of tests of three different debonding techniques applied to three different types of ceramic brackets revealed the following: (1) The incidence of bracket failure during debonding was significantly greater with conventional debonding recommended by the manufacturer (10-35%), as compared with the incidence associated with either the ultrasonic or the electrothermal methods (0%). (2) Bond failure at the bracket-adhesive interface occurred with significantly greater frequency for the Starfire brackets when debonding was performed with the electrothermal instrument and with significantly less frequency when the debonding pliers were used. Combination bond failures, in which part of the adhesive stayed on the enamel and part stayed on the bracket, occurred with significantly greater frequency when Transcend and Starfire brackets were debonded with debonding wrenches than when other methods were used. Combination-bond failures occurred with significantly less frequency when the brackets were removed with ultrasonic tips or with the electrothermal instrument. (3) The debonding times for the ultrasonic method were significantly greater than the times for either the conventional or the electrothermal methods. There were no significant differences among the debonding times for the three bracket types. There were no significant differences in the debonding times between the electrothermal method (means = 3.0 seconds) and the conventional bracket-removal method (means = 1.0 seconds). (4) Enamel loss as a result of adhesive removal was not significantly different among the three adhesive-removal techniques tested. Post-treatment roughness of the enamel surface was greater for the high-speed adhesive-removal technique than for either the low-speed or ultrasonic adhesive-removal methods.