Aligning Effectiveness, Secretion of Interleukin 1β and Pain Control During Fixed Orthodontic Treatment with Self-Ligating Appliances and Supplemental Vibrational Appliances. A Randomized Controlled Clinical Trial

The aims of the present study were to investigate rate of mandibular incisors alignment, levels of IL-1 and pain and discomfort during orthodontic alignment with the following: 1) conventional-ligating appliance (CLA); 2) self-ligating appliance (SLA); 3) self-ligating appliance combined to vibrational appliance (SLA-VA). Methods: This was a three-armed parallel group randomized clinical trial with allocation ratio 1:1:1. The main inclusion criteria were: full permanent dentition, age below 25 years, no missing teeth, first skeletal and molar class, non-extraction treatment, Little's Irregularity Index (LII) from 3mm to 6mm. The main outcomes were rate of mandibular incisors alignment, concentration of IL-1 and pain and discomfort. Measurements on models were performed at appliance placement (t0) and at monthly intervals for the first 3 months (T1, T2, T3), whereas IL-1 levels were measured at weekly intervals for the first 3 weeks (t1, t2, t3). Differences between groups for normally-distributed variables were initially estimated through Analyses of Variance (ANOVAs) tests, followed by Post-Hoc Scheffe analysis for pair wise comparisons. Results: Thirty-three patients were recruited and randomized with no lost to follow-up. During the first two months, faster alignment was observed for SLA (P=0.0491) and SLA-VA (P=0.0134) compared to CLA. At each time-point of measurement no differences were observed between SLA and SLA-VA. At t1 and t2 were found higher values of IL-1 for SLA-VA compared to SLA (P=0.0209, P=0.0352) and CLA (P=0.0018, P=0.0029), whereas at t3 the difference persisted only versus CLA (P=0.0304). No relevant differences in terms of pain and discomfort were observed between groups at any time point. Conclusions: Self-ligating appliances seem to perform better than conventional-ligating appliances in terms of timing of teeth leveling and alignment. Vibrational devices seem to enhance secretion of IL-1 but do not increase effectiveness of leveling and alignment with regard to treatment acceleration or pain reduction.