ADRF Trebitsch Scholarship. The microbial contamination of toothbrushes. A pilot study

Ten individuals were each supplied with a new toothbrush of the same type and brand, together with identical tubes of fluoridated toothpaste. After a three-week period, during which subjects were asked to follow their usual oral hygiene practices, the toothbrushes were collected and assayed for microbial contamination using a range of selective growth media. The total microbial load per toothbrush was found to be 10(4) to 10(5) colony forming units. Staphylococci were found on all toothbrushes and streptococci on all but one. These two genera were also quantitatively dominant. Candida, corynebacteria, pseudomonads and coliforms were identified in 70, 60, 50 and 30 per cent of toothbrushes, respectively. However, mutans streptococci, lactobacilli and black-pigmented Gram-negative anaerobic rods were not detected on any of the toothbrushes. For each individual, information on variables such as toothbrush rinsing practices and post-brushing storage methods and environment was collected. No obvious relationship between such variables and microbial load was apparent but it is suggested that more extensive studies are needed, taking into account additional parameters such as age and degree of toothbrush wear and the use of pre-brushing mouthwashes.