In vitro evaluation of the retention of three species of pathogenic microorganisms by three different types of toothbrush

The retention and survival of microorganisms on toothbrushes pose a threat of recontamination for certain patients at risk. In order to measure the in fluence of brush design and optimize the choice of toothbrush model for com plementary studies, the in vitro retention of three microbial species (Porp hyromonas gingivalis ATCC 33277, Streptococcus mutans ATCC 25175 and Candid a albicans ATCC 26555) was evaluated for three types of toothbrush. Two ser ies of standardized experiments were carried out for each brush and microor ganism. The first series tested the retention of the microorganisms on the head portion of the brush, while the second measured retention on the head of the brush and the part of the handle inserted in the mouth during brushi ng. For each series, the microorganisms were counted at T-0 and T-24 (after storage of the brushes at room temperature for 24 h). Depending on the mic roorganism studied, from 0.2% to 2% of the initial inoculum was retained on the brush. The number detected increased with the size of the exposed area . After 24 h, P, gingivalis and S. mutans were found on only one type of br ush. C. albicans survived on all three. These results confirm that microorg anisms can quickly colonize toothbrushes.