Effect of the antibacterial agents octenidine and chlorhexidine on the plaque flora in primates.

The effect of the antibacterial substance octenidine on plaque formation and on oral microflora in eight monkeys fed a sucrose diet was studied. Plaque was obtained from buccal tooth surfaces of premolars and first molars in two quadrants using a swab and a dental carver and examined using culture and fluorescent antibody procedures. A significant reduction in plaque score was observed on the buccal tooth surfaces after daily topical application of 1% solutions of octenidine and chlorhexidine for 7 d; octenidine was more effective than chlorhexidine. Placebo treatment with water was without significant effect. Octenidine and chlorahexidine affected the plaque flora in a similar manner; the proportion of S sanguis increased in relation to baseline levels while the population of Actinomyces, especially the group A. viscous and A. naeslundii, was markedly reduced. S. sanguis showed an inverse relationship to members of actinomyces in response to the action of the antimicrobial agents. Both plaque sampling methods revealed similar changes in bacterial composition as a result of treatment. The data show that octenidine is an effective inhibitor of dental plaque and its antimicrobial and antiplaque properties make it worthy of further studies.