Toothpastes containing 0.3% and 0.5% triclosan. II. Effects of single brushings on salivary bacterial counts.

For antimicrobials such as chlorhexidine antiplaque activity appears due to persistence of considerable antimicrobial action in the mouth. The substantivity of antimicrobial compounds can be evaluated by measuring the magnitude and duration of salivary bacterial counts following a single exposure. Such data has been shown to correlate with plaque inhibitory properties of antimicrobial compounds. This study measured the effects of single brushings with 0.3% and 0.5% triclosan with or without PVM/MA copolymer in toothpastes on salivary bacterial counts in 14 young adults. The results were compared with single rinsing with a 0.2% chlorhexidine solution, water and a single brushing with a commercial fluoride toothpaste. The study was a 7 cell cross-over design, randomized using a 7x7 latin square design. Chlorhexidine produced large and significant reductions which persisted to the 7 hour measurement time with no indication of count recovery at this time. The triclosan pastes containing the copolymer produced significant reductions which did not persist beyond 5 hours and evidence of bacterial count recovery with a paste containing triclosan but no copolymer (increments) was apparent after 30 minutes. The water and control paste produced no significant effects on counts. Intertreatment comparisons showed the chlorhexidine rinse more effective than all other preparations in all time periods. Some of the triclosan toothpastes containing the copolymer produced significantly greater effects compared to water or the control paste at some, but not all time periods. There was little difference between the triclosan pastes with the copolymer. Nevertheless, the duration and magnitude of salivary bacterial count reductions seen with the triclosan toothpastes may explain the plaque inhibition effect.