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
1. Unit of Orthodontics, Dental School, Department of Surgical Sciences, University of Torino, Italy
2. School of Dentistry, University of Manchester, JR Moore Building, Oxford Road, Manchester, M13 9PL, UK
3. Unit of Gnatology, Dental School, Department of Surgical Sciences, University of Torino, Italy
4. Unit of Experimental Medicine and Clinical Pathology, Department of Clinical and Biological Sciences, University of Torino, Italy.
Aims: The aims of the present study were to investigate rate of mandibular incisors alignment, levels of IL-1β 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-1β 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-1β 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-1β 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-1β but do not increase effectiveness of leveling and alignment with regard to treatment acceleration or pain reduction.
Keywords: Orthodontic movement, acceleration, IL 1β, pain and discomfort