Comparison of different clear aligner systems with fixed orthodontic treatment in terms of endocrine-disrupting monomer release, treatment effectiveness and efficiency : An in vivo randomized clinical trial.

PURPOSE: The aim of this four-arm parallel trial was to evaluate and compare directly and indirectly produced clear aligners with fixed orthodontic treatment in terms of bisphenol A (BPA) release, as well as treatment effectiveness and efficiency.

METHODS

In all, 52 patients were randomly allocated to four treatment groups according to the appliance system used: direct three-dimensionally (3D)-printed aligners (group A), Invisalign aligners (Align Technology, Santa Clara, CA, USA; group B), ClearCorrect aligners (Round Rock, TX, USA; group C), and fixed orthodontic appliances (group D). Saliva samples were collected at baseline and at multiple time points during the first and final weeks of treatment to evaluate salivary BPA levels. Intraoral scan records were obtained at the beginning and end of treatment. High-performance liquid chromatography was used to analyze the saliva samples, and the Peer Assessment Rating (PAR) index was employed to evaluate treatment effectiveness. In addition, total treatment duration was assessed.

RESULTS

No statistically significant difference was observed between the groups regarding the BPA values measured in saliva at different time points, nor in the percentage reduction of PAR score values (p > 0.05). Total treatment duration was 6.59 ± 1.42 months in group A, 5.36 ± 1.63 months in group B, 5.72 ± 1.88 months in group C, and 10.16 ± 2.28 months in group D. The fixed orthodontic treatment group (group D) had a longer treatment duration than the other groups (p < 0.001).

CONCLUSION

No differences in BPA release were observed among the different treatment modalities. Additional long-term studies are needed to clarify the biological relevance of these findings. In terms of treatment effectiveness, no significant difference was observed between direct and indirect clear aligner techniques and fixed orthodontic treatment. The overall duration of fixed orthodontic treatment was longer than that of clear aligner therapies.