In-vivo evaluation of the bacterial contamination and disinfection of acrylic baseplates of removable orthodontic appliances

Abstract

This randomized clinical trial assessed, by using microbial culture and scanning electron microscopy (SEM), the contamination by mutans streptococci (MS) colonies/biofilms on acrylic baseplates of removable orthodontic appliances and evaluated the efficacy of antimicrobial sprays (Periogard [Colgate-Palmolive Ind. Brasileira, Osasco, SP, Brazil], Cepacol [Merrell Lepetit Farmacêutica e Industrial Ltda, Santo Amaro, SP, Brazil], and sterile tap water [control]) on their disinfection. Seventeen children were randomly enrolled in a 3-stage changeover system with a 1-week interval between each stage. All solutions were used in all stages by a different group of children. The acrylic baseplates were worn full time except at meals. At the end of each week of the trial, the baseplates were submitted to a randomized disinfection protocol and were sent for microbiologic analysis. New baseplates were constructed, and the same sequence of procedures was repeated 2 more times. Acrylic baseplates representing each test solution were examined by SEM. The Friedman test assessed differences at the 5% significance level among the solutions for MS biofilm formation on acrylic surface. Cepacol and Periogard reduced the formation of MS colonies/biofilms, and both solutions differed statistically from sterile tap water (P <.001). However, Periogard was significantly more effective against MS than Cepacol (P <.001). When MS colonies/biofilms were detected on acrylic surfaces under stereomicroscopy, this was confirmed with SEM. Acrylic baseplates of removable orthodontic appliances worn by children were contaminated by MS colonies/biofilms in all cases after 1 week. Although Cepacol had better results than sterile tap water, spraying with Periogard showed significantly greater efficacy in reducing MS colonies/biofilms on acrylic surfaces.