Influence of operator, tool, dental loupes and tooth position on enamel loss and composite remnants after removal of composite attachments for orthodontic clear aligners: an experimental study using 3D profilometry

Purpose: To assess the influence of operator, tool, dental loupes, and tooth position on enamel loss and composite remnants after removal of composite attachments (CA) for orthodontic clear aligners. Procedure duration was also analyzed.
Materials and methods: Eight maxillary resin dental arches with four natural teeth were placed in the right posterior sector in dental simulators, and CA was realized. The dental arches were randomly distributed according to three experimental factors: operator (junior, senior), tool (tungsten carbide bur and silicone polisher, only silicone polishers), and use of dental loupes. Dental arches were scanned with 3D profilometry before and after CA removal to measure enamel surface height variation (ESHV), particularly enamel loss in the CA area. Digital microscopy was used to detect composite remnants.
Results: The mean enamel loss was -22.7 ± 29.4 µm (range -132 to 0 µm). It was not significantly influenced by experimental factors or tooth position. Composite remnants were found in 34.4% of teeth, significantly more in senior than in junior operators (p = 0.038). They were more frequent with silicone polishers than with tungsten carbide burs (p = 0.0005) and were reduced using dental loupes (p = 0.0090). Junior operators worked faster than senior operators (p = 0.031), but the latter were quicker when using the dental loupes (p = 0.012).
Conclusion: Aligner CA removal induces enamel damage or leaves composite remnants on its surface. The presence of composite remnants is influenced by the type of tool and can be reduced by using dental loupes, which also lowers working time.