Evaluation of enamel surface roughness after orthodontic debonding and adhesive resin removal using Zirconia Burs, Tungsten Carbide Burs, and White Stone Burs: an in vitro comparative study

Abstract

Abstract Background The main goal of orthodontic debonding is to restore the enamel surface as closely as possible to its pretreatment condition without causing severe iatrogenic damage. This study aimed to compare the effects of different adhesive removal burs; zirconia burs, tungsten carbide burs, and white stone burs on enamel surface roughness.Materials and Methods Total sample of 72 extracted premolars was randomly divided into three equal groups (n = 24) depending on the method of adhesive removal: zirconia burs (ZB); tungsten carbide burs (TC); and white stones (WS). Before bonding, the initial surface roughness (Ra) at T0 was evaluated using a profilometer and Scanning Electron Microscopy (SEM). The metal brackets were bonded and debonded after 24 hours using a debonding plier, then the adhesive remnants were removed using the different burs. The second Ra at T1 was evaluated and the time consumed for adhesive removal was recorded in seconds. Final polishing was performed using Sof-lex discs and Sof-lex spirals, then the third Ra evaluation at T2 was performed.Results All resin removal techniques significantly increased surface roughness compared to the baseline in all groups. Ra values and SEM images concluded that the lowest surface roughness was observed in the ZB group, followed by the TC group, and WS group. Although the fastest procedure was performed with WS, followed by ZB, then TC. After polishing the Ra values significantly decreased in all groups.Conclusion zirconia burs were comparable to tungsten carbide burs and can be considered alternatives to white stones which caused severe enamel damage. The polishing step created smoother surfaces regardless of the burs used for resin removal.