Evaluation of enamel surface after removal of clear aligner composite attachments using different methods: An in-vitro randomised study

OBJECTIVE: To evaluate bovine enamel surfaces after removal of clear aligner composite attachments using different methods, considering temperature, noise and vibration generated by rotating instruments. The null hypothesis stated that there would be no differences among methods. MATERIAL AND METHODS: A total of 56 specimens were randomly assigned to seven groups according to the removal technique: pencil-tip diamond bur at high-speed (CG); latch-lock multiblade bur at low-speed (LG); friction-grip multiblade bur at high-speed without irrigation (HG); friction-grip multiblade bur at high-speed with irrigation (HIG); aluminium-oxide tips at low-speed (AOG); Sof-Lex™ Pop-On discs at low-speed (SLG), applied from coarse to fine; and Enhance silicone tips at low-speed (EG). Surface roughness was measured using a 3D optical profilometer (Nanovea PS50) and microhardness with a Knoop microhardness tester (Buehler MICROMET 5104). During composite removal, temperature was monitored with a digital infrared thermometer (Lasergrip GM 400), noise with a decibel metre (DL-1100), and vibration with a vibration metre (WT63A). SLG showed the smallest mean change in roughness (ΔRa: 0.46 ± 0.57). CONCLUSION: All removal methods increased enamel roughness and reduced microhardness, with significant differences in temperature, noise and vibration. AOG and SLG caused less enamel damage and better surface preservation, indicating they may represent safer clinical options. The null hypothesis was therefore rejected.