Bacterial survival rate on tooth- and interdental brushes in relation to the use of toothpaste

Previous studies indicated that oral hygiene aids can play a rôle in the intra-oral translocation of pathogens. The survival rate of cariogenic and periodontopathogenic species on toothbrushes, with and without toothpaste, and interdental brushes was presently investigated. 12 periodontitis patients had their interdental spaces professionally cleaned with interdental brushes and their teeth with new toothbrushes with or without different dentifrices. Each time brushes were rinsed with tap water and stored dry at room temperature. At different time intervals an interdental brush or 4 tufts from a toothbrush were processed for vitality staining and selective and non-selective culturing procedures. Immediately after rinsing, a toothbrush without toothpaste harboured 10(7), 10(8) and 10(7) colony forming units (CFU) of respectively aerobic, anaerobic and black pigmented species. An insignificant decrease occurred the first 24 hours and after 48 hours still 10(4) CFU of aerobic and anaerobic species could be cultured. No periodontopathogen remained detectable at 8 hours, except for Fusobacterium nucleatum. The proportion of vital bacteria decreased in 48 hours from 50% to 30%. Comparable results were obtained for interdental brushes. The bacterial survival rate on toothbrushes was significantly reduced by the use of a detergent containing toothpaste by 2 log at baseline, another 2 log at 4 hours and an extra log more at 8 hours for aerobic and anaerobic species. A toothpaste without detergent only had an insignificant bactericidal effect. Toothpaste detergents decrease the survival rate of pathogenic species on a toothbrush and can thus limit the risk for bacterial translocation.