Abstract
OBJECTIVE: The aim of this RCT was to analyse the relationship between intermittent vibratory forces and external apical root resorption (EARR) in patients treated with clear aligners, building on prior research on vibrational effects on biomarkers. MATERIALS AND METHODS: A parallel, three-arm randomised clinical trial included adults to be treated with clear aligners, randomly assigned by a computerised randomisation list to: Group A (vibration from treatment onset), Group B (vibration after 6 weeks), or Group C (no vibration). While patients and orthodontists were aware of group assignments, evaluators remained blinded. Digital orthopantomographs (OPGs) taken at treatment initiation (T0) and completion (T4) were analysed using Linge & Linge, Fritz & Krieger, and Malmgren methods. Crevicular fluid levels of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) were measured as bone remodelling markers at different time points (T0, T1, T2, T3, T4). RESULTS: Fifteen patients were analysed in Groups A and C, and 14 in Group B. No significant differences in EARR were found between groups, except for a significant increase in Group B (T2-T0) using Fritz & Krieger correlated with OPG (p = 0.010). Mean EARR was 4.13% (Group A), 4.08% (Group B), and 2.52% (Group C) using Linge & Linge; and 3.26%, 2.82%, and 2.12%, respectively, using Fritz & Krieger. No adverse effects were observed. CONCLUSION: The effect of intermittent vibratory forces on EARR remains inconclusive, highlighting the need for further research to optimise vibration protocols and understand its impact. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05316636.