Effects of toothbrush-generated vibration and ultrasound on pain perception following orthodontic elastomeric separation: a randomized controlled clinical trial

Introduction
Vibration and ultrasound have been recently introduced as methods to enhance orthodontic treatment. Beside the limited number of clinical trials evaluating their effectiveness on modulating pain perception, no clinical trial has reported a comparison of these two methods.

Objectives
The aim of the present study was to investigate the effectiveness of vibration and ultrasound on pain perception alleviation, and to compare the efficacy of both interventions given that no previous study has investigated these aspects.

Material and methods
The research sample consisted of 36 patients, who were randomly assigned into three equal groups (vibration group, ultrasound group, and control group). After elastomeric separator placement, two interventional groups were requested to apply vibration and ultrasound for 5 minutes twice-daily on each upper first molar, whilst control group was not subjected to any physical stimulus. In conjunction with this procedure, a pain assessment questionnaire was distributed to all patients, and a daily assessment by visual analogue scale (VAS) was carried out for 5 days since separators placement.

Results
Subjects in vibration group had lower pain scores at all time-points with significant decrease of pain at the first, fourth, and fifth days of application, compared with ultrasound and control groups. No significant differences were noted between ultrasound and control groups among all observational time-points.

Conclusions
Five-minutes, twice-daily application of vibration contributes to the reduction of pain associated with elastomeric separator placement, and could be a suitable method for pain control in the daily orthodontics practice.