Debonding of Clear Aligner Attachments With Fluorescence-Aided Identification Technique (FIT): An In Vitro Study

The aim of this in vitro study was to investigate whether removing fluorescent clear aligner attachments under UV light improves the efficiency of attachment removal and reduces enamel loss and composite residue.

Clear aligner attachments were bonded to bovine teeth using fluorescent-modified composite (AlignerFlow LC, VOCO, Germany); 20 models were prepared. In a split-mouth design, attachments were removed either using a fluorescence-aided identification technique (FIT) under UV light, or with standard white light (non-FIT). Removal time was recorded for each attachment. Intraoral surface and optical coherence tomography (OCT) scans (T0, T1) were analyzed to quantify enamel loss and composite residue using Avizo Software, while OCT scans were assessed using a dichotomous scale for enamel loss and a four-point scale for composite residue.

Although there is a trend toward faster attachment removal with FIT, measurements of removal time did not differ significantly between the groups due to high inter-individual variability. Volumetric analysis revealed a significant reduction in composite residue with FIT, while no significant differences in enamel loss were detected between the groups. OCT measurements revealed no significant differences between groups, as composite residue and enamel loss occurred on a microscopic scale in most of the specimens, regardless of the debonding method.

While neither debonding time nor enamel loss were affected, FIT significantly reduced residual composite after attachment removal, suggesting that FIT may contribute to more standardized clinical outcomes. Future in vivo studies with larger sample sizes, multiple operators, and different adhesive systems are needed to validate these findings.