A Preliminary Study of Effects of Ceramic Orthodontic Bracket and Residual Adhesive Removal Methods on Enamel Microcracks

A Preliminary Study of Effects of Ceramic Orthodontic Bracket and Residual Adhesive Removal Methods on Enamel Microcracks

Introduction: We aimed to evaluate the effects of ceramic orthodontic brackets and residual adhesive removal methods on enamel microcracks. Methods: Thirty extracted premolars were collected, and the location, length, and width of enamel microcracks were measured using scanning electron microscopy (SEM). Based on visibility, the teeth were categorized as follows: Group 1, with pronounced enamel microcracks visible under indoor lighting (n=12); Group 2, with weak enamel microcracks detectable only under SEM (n=12); and Group 3, the control group (n=6). In Groups 1 and 2, ceramic brackets were bonded and removed using a bracket-removing plier, followed by residual adhesive removal with either a carbide burr or sandblasting. In contrast, the teeth in Group 3 were air-dried without any additional procedures. A second SEM analysis reassessed the enamel microcracks, and these were compared with those in the first SEM analysis. Results: After removing the ceramic brackets and residual adhesive, the width and length of both pronounced and weak enamel microcracks increased in both the carbide burr and sandblasting groups, with no significant difference between the groups. Pronounced microcracks significantly increased in the cervical third of the teeth, whereas weak microcracks increased in the middle third. Notably, all weak microcracks transformed into pronounced microcracks. Conclusions: Removing residual adhesive after debonding ceramic brackets can exacerbate enamel microcracks. Since both the carbide burr and sandblasting methods increased the width and length of the enamel microcracks, with no significant difference between them, considering this risk is important if microcracks are detected before treatment. (Clin J Korean Assoc Orthod 2024;14(4):257-269)