Comparative effects of toothpaste brushing and toothpaste rinsing on salivary bacterial counts

The persistence of antimicrobial action of compounds and formulations in the mouth can be demonstrated by recording the magnitude and duration of the reduction of salivary bacterial counts following a single application. Such measures of substantivity appear to correlate with the plaque inhibitory properties of antimicrobial agents. For toothpastes, studies on the short-term inhibition of plaque formation use a number of delivery methods to measure the direct effect of the preparation divorced from toothbrushing. Such methods include paste slurries, paste in trays or cap splints. This study determined whether toothbrushing with a toothpaste produced the same effects on salivary bacterial counts compared to rinsing with a slurry. A group of 24 volunteers brushed or rinsed with a slurry of a commercial toothpaste. Each regimen was repeated twice on 4 separate days by all volunteers and salivary bacterial counts recorded at baseline and time periods to 7 hours. There were no significant differences between brushing or slurry rinsing on salivary bacterial counts and each method produced reproducible effects. This supports the use of the slurry method where the direct plaque inhibitory action of an antimicrobial toothpaste is to be assessed; and indicates that both methods equally make available and activate the relevant ingredients in formulations.