Biofilm associated microorganisms on removable oral orthodontic appliances in children in the mixed dentition.

Biofilms on removable orthodontic appliances act as reservoir of microorganisms, capable of modifying the environmental condition of oral cavity and are difficult to be removed with routine hygiene measures. The present investigation includes enumeration, identification and numerical analysis of different types of cultivable bacteria associated with the biofilms on removable orthodontic appliances. Removable appliances of 25 healthy children among the ages of 10 to 14 years were taken to measure the prevalence of biofilms and type of microorganisms. For isolation of microorganism from biofilms different types of selective and non-selective medium based on standard methods were used. The data were further analysed by using Kolmogorov-Smirnov test, one-sample t-test and Spearman rank correlation coefficient. The percentage frequencies of isolates were also calculated The survey revealed the presence of both multi-species and mono species biofilms on appliances, with Non-Streptococci, anaerobic bacteria, Streptococcus spp., members of the family Enterobacteriaceae and Lactobacillus spp. as a dominant microbial flora of biofilms. Bacillus sp. and Candida sp. were isolated from one sample each. Significant positive and negative correlations were established among the species isolated from biofilms. Higher prevalence of the members of the family Enterobacteriaceae were reported during this study, advocating an extra hygienic measure is essential for this age group while wearing acrylic orthodontic appliances in oral cavity.