Evaluation of enamel integrity after clear aligner attachments removal: a risk–benefit comparison of one-step tools

Abstract

Background. At the end of clear aligner treatment, attachment removal is essential to restore natural tooth morphology while preserving enamel integrity. This study aimed to compare the effects of seven different composite removal instruments on the enamel surface using a risk–benefit model. Materials. The instruments assessed were: OneGloss, Enhance, SM 104, Sof-Lex disc (coarse grit), tungsten carbide bur, zirconia bur, and white stone bur. Seventy extracted premolar teeth were bonded with standardized condensable composite attachments (2 × 4 × 1 mm). Enamel integrity was quantitatively assessed by measuring surface roughness (µm) and enamel loss depth (mm), and qualitatively analyzed using scanning electron microscopy (SEM). The time required for attachment removal was recorded in seconds. A risk–benefit model was applied to compare enamel damage and time efficiency across tools. Results. White stone bur exhibited higher surface roughness and greater enamel loss compared to other groups (p = 0.000). Aluminium oxide-based tools (OneGloss, Enhance, SM 104, and the Sof-Lex disc) resulted in less enamel loss than the tungsten carbide bur. The risk–benefit model indicated that OneGloss, Enhance, and SM 104 offered the best balance between enamel preservation and time efficiency. SEM analysis further confirmed that OneGloss and SM 104 produced smoother enamel surfaces compared to other instruments. Conclusion. OneGloss and SM 104 demonstrated superior time efficiency and preservation of enamel integrity compared to other evaluated tools.