Efficacy of a wax containing benzocaine in the relief of oral mucosal pain caused by orthodontic appliances

Abstract

During orthodontic treatment, pain and discomfort of the oral mucosa can be experienced as a result of trauma from the appliances caused by increased friction between mucosal tissue and the surface of the brackets. Currently, orthodontists have few remedies to prevent or relieve this mucosal irritation. The orthodontist can give the patient wax to cover the brackets as a prophylactic measure or to use as needed on specific irritating appliances. Orthodontic wax contains no analgesic components. The purpose of this study was to determine the efficacy of an orthodontic wax containing benzocaine that is released over time in a controlled manner. This randomized, prospective, double-blind, clinical trial compared patients' responses to the wax with benzocaine and the currently used unmedicated orthodontic wax. Seventy patients, 35 in each treatment group, were instructed to apply the wax in a specific manner, and their pain levels were recorded at 6 different time points. The pain levels were analyzed with a repeated-measure analysis of variance (ANOVA) model with factors of treatment (medicated wax vs unmedicated wax) and times (6 levels). Post-hoc pair-wise comparisons were made on the basis of the Fisher least significant difference procedure. The results of this study clearly indicated that the pain profile over time of the group that received the wax containing benzocaine was significantly different from that of the subjects who received the unmedicated wax. The medicated group had significantly lower pain levels at every time point after the first hour (P <.0003 in each case) compared with the unmedicated group. The medicated wax was effective immediately and continued to reduce pain in greater magnitude than did the unmedicated wax. A wax applied to orthodontic brackets that slowly and continuously releases benzocaine is significantly more effective at reducing the pain associated with mucosal irritation than is the current option used by most orthodontists. (Am J Orthod Dentofacial Orthop 2002;122:359-65)