An in vitro comparison of antimicrobial toothbrushes

The purpose of this study was to determine the efficacy of toothbrushes that advertise self-disinfecting, antimicrobial properties due to the inclusion of silver nanoparticles or chlorhexidine in the bristles. Three different types of toothbrushes-silver nanoparticle, chlorhexidine-coated, and a control-were submerged in suspensions of Streptococcus mutans and Candida albicans. At designated times postinoculation, organisms were removed from the toothbrush heads, then serially diluted, plated, and incubated. The colony-forming units (CFUs) were counted and a mean percent reduction was determined for each organism group. With the S. mutans groups, the chlorhexidine-coated toothbrushes had significantly greater percent reduction in CFUs at all 3 time points compared to the control or silver nanoparticle toothbrushes. With the C. albicans groups, neither the chlorhexidine-coated nor the silver nanoparticle toothbrushes had a significant reduction in CFUs compared to the control. Neither of the antimicrobial toothbrushes delivered the advertised claim of a 99.9% reduction in CFUs with either microorganism. However, the inclusion of chlorhexidine in toothbrush bristles appeared to be the most promising of the methods tested for toothbrush self-disinfection.