Effect of different resin removal methods on enamel after metal and ceramic bracket debonding : An in vitro micro-computed tomography study.

Abstract

The aim of this study was to conduct an in vitro evaluation of the effects of different adhesive debonding and polishing techniques performed after metal and ceramic bracket removal on enamel using micro-computed tomography (micro-CT). This study was performed on 42 extracted maxillary first premolars divided into 2main groups and 6subgroups as follows: metal (group1) or ceramic (group2) brackets were bonded to the teeth, then, after debonding, one of three different methods was used to remove the residual adhesive: tungsten carbide burs with pumice(A), fiber-reinforced composite burs and polishing paste(B), or Sof-Lex discs(C; 3M Dental, St Paul, MN, USA). The samples were evaluated by micro-CT before bracket bonding (T0) and after resin removal (T1). Demineralization area, demineralization depth, demineralization volume, mineral density, and mineral volume were measured. At T1, demineralization area was significantly larger in groups1A and2A compared to groups1B, 1C, 2B, and2C (P = 0.001). Group2A (ceramic bracket/tungsten carbide-pumice) had the highest demineralization volume (P = 0.001). When the groups were compared in terms of change from T0 to T1, groups1A and2A showed significantly larger changes in demineralization area compared to the other 4groups (P = 0.001). The increase in demineralization volume was larger in group2A compared to all other groups (P = 0.001). All resin removal methods damaged the enamel surface to varying degrees. Regardless of bracket type, the use of tungsten carbide and pumice should be avoided when cleaning the tooth surface after debonding. Use of composite burs and Sof-Lex discs in particular after the debonding of ceramic brackets will help minimize damage.