THE USE OF DEBONDING PLIERS IN THE REMOVAL OF CERAMIC BRACKETS - FORCE LEVELS AND ENAMEL CRACKS

The purpose of this study was to determine the magnitude of the applie d forces when using pliers as a debonding method for removing three ty pes of ceramic brackets. The following variables were evaluated: debon ding strengths, the Adhesive Remnant Index, and enamel damage with tra nsillumination. All the brackets in this investigation were debonded w ith a direct bond remover plier. An Instron Model Universal testing ma chine was used to measure debonding strengths. From the results of thi s study, the following conclusions can be drawn: (1) The diamteral com pression mean bond strengths for the three bracket types tested ranged from a low of 67.8 Kg/cm(2) to a high of 102.9 Kg/cm(2) and are in th e clinically acceptable range for orthodontic force application. (2) T here was no significant difference in the mean bond strengths of the t hree ceramic brackets tested. (3) The ARI scores were found to range b etween 2 and 4 indicating a cohesive type of bond failure. (4) Transil lumination was used to evaluate minute enamel damage, and the results indicated that most of the teeth (82.02%) experienced no increase in e namel cracks after debonding. The teeth that showed an increase in the number of cracks after debonding had a significantly higher mean bond strength (113.0 Kg/cm(2)) than those with no increase in the number o f cracks (72.9 Kg/cm(2)).