Comparative evaluation of ultraviolet and microwave sanitization techniques for toothbrush decontamination

BACKGROUND: Toothbrushes are rapidly contaminated with different microorganisms representing a possible cause of infection or reinfection especially in the periodontal patients under therapy. The purpose of this study was to evaluate the sanitization of toothbrushes previously contaminated by various oral microorganisms using a domestic microwave oven and commercial ultraviolet (UV) light toothbrush sanitizer. MATERIALS AND METHODS: Thirty male dental graduates were randomly assigned to control or experimental groups and received standardized toothbrushes for home use. Each subject was instructed to use it with the standardized modified Bass technique for 1 week and submit it to the investigator after use. Collected toothbrushes were cultured and analyzed for the number of colony-forming units (CFUs). In the next phase, once again a new set of toothbrush was given to each subject and instructed to use it for one more week and follow the same instructions as given earlier. Subsequently, the used toothbrushes were again collected and were sanitized by microwave irradiation, UV radiation, or were not sanitized (control group). After the sanitization procedure, toothbrushes were again cultured for the number of CFUs. The collected data of the presanitized and postsanitized CFU count were log transformed to normalize their distributions prior to analysis. Furthermore, log CFU data were compared and analyzed by one-way ANOVA, Tukey's post hoc procedure, and paired t-test for the difference in the mean at P<0.05. RESULTS: Result showed that after the sanitization procedure, there was a significant (P<0.001) reduction in microbial contamination in both microwave and UV group toothbrushes compared to control group toothbrushes whereas the microbial count in the microwave group was significantly less (P<0.001) compared to the UV group. CONCLUSIONS: The evidence presented in this study suggests that microwave irradiation is an effective disinfectant agent for bacteria and fungi on toothbrushes.