The effects of 0.5% chlorhexidine and 0.2% triclosan containing toothpastes on salivary bacterial counts

A number of antimicrobial compounds could be incorporated into toothpastes to enhance plaque inhibitory effects. However, the number of possible formulations is immense and makes clinical testing in plaque and gingivitis studies difficult. In this study, the effects on salivary bacterial counts of a number of chlorhexidine and triclosan toothpastes was evaluated as a predictor of persistence of antimicrobial action in the mouth. The study was a supervised, randomised 15-way crossover study employing 10 healthy human volunteers. All toothpastes were brushed for 1 min and comparison made with a 0.2% chlorhexidine rinse. The latter produced a large drop in salivary bacterial counts to the end of the 7-h study period. The toothpastes decreased salivary bacterial counts and all but two had notably more effect than a water brushing. No toothpaste showed a significant persistence of antimicrobial effect beyond 5 h. In the light of available plaque inhibition data for the toothpastes, persistence of antimicrobial activity beyond 5 h will be necessary for a clinical effect on plaque and gingival health. The method appears to be a simple and rapid screening technique for products formulated to enhance plaque inhibition mediated through an antimicrobial action.