Patient-Reported Outcomes for Different Orthodontic Thermoplastics Used in Clear Aligners

Clear aligner therapy is an esthetic orthodontic treatment modality that uses removable thermoplastic trays to correct dental alignment. Different thermoplastic materials, including thermoplastic polyurethane (TPU) and polyethylene terephthalate glycol (PETG), may differ in flexibility and mechanical behavior. These material differences may influence patient-reported outcomes such as pain, mucosal ulceration, tooth sensitivity, tooth mobility, and material-related allergic symptoms. This randomized, double-blind, parallel-group clinical trial will compare patient-reported outcomes in patients treated with clear aligners fabricated from TPU versus PETG. Participants requiring non-extraction clear aligner therapy for mild to moderate crowding will be randomly allocated in a 1:1 ratio to receive aligners fabricated from either PETG or TPU. Outcomes will be recorded at five predefined time points after aligner assignment and wear: T0 before aligner wear, T1 immediately after aligner insertion/wear, T2 at day 1, T3 at day 3, and T4 at day 7.