Background and Aim: Contaminated toothbrush has important role in transmission of infection and disease. The purpose of this study was to evaluate two methods of toothbrush disinfection by sodium hypochlorite 0/1% and microwave on three types of microorganisms: staphylococcus aureus, streptococcus mutans and candida albicans.

Materials and methods: In this in vitro study, 90 toothbrushes were divided into 9 groups (n=10). Toothbrushes were contaminated by standard suspension of streptococcus mutans, staphylococcus aureus and candida albicans. Then, toothbrushes were disinfected with hypochlorite sodium %0.1 for 10 minutes and with microwave for 1 minute. Afterwards, remained bacteria on surface of toothbrush were cultured and counted. For analyzing Numbers of Colony-Forming Units remained on toothbrush one-way Kruskal-Wallis and Mann-Whitney tests were used.

Results: Results of this study showed that significant difference exists among disinfectant effects (p<0.001). Results of Mann-Whitney  test showed hypochlorite sodium had more disinfecting effect on Streptococcus mutans and Candida albicans compared with distilled water or microwave (p<0.05).However disinfecting effect of microwave was more than two other disinfectants on Staphylococcus  aureus(p<0.05).

Conclusion: hypochlorite sodium had more disinfecting effect on Streptococcus mutans and Candida albicans however microwave was more effective on Staphylococcus aureus.