AN IN-VITRO MOUTH MODEL TO TEST ANTIPLAQUE AGENTS - PRELIMINARY STUDIES USING A TOOTHPASTE CONTAINING CHLORHEXIDINE

The development of an in vitro model simulating the oral cavity has al lowed the antiplaque activity of a toothpaste containing 0.004% chlorh exidine to be tested. The model is based on the continuous irrigation of bovine tooth samples with artificial saliva. Scanning electron micr oscopy showed homogeneous colonization of monobacterial plaque by Stre ptococcus mutans on dental surfaces under these model conditions. The enamel was colonized with regular cell clusters showing a globular app earance. The globules coalesced with increasing plaque thickness. Trea tment with toothpaste containing 0.004% chlorhexidine showed a more ma rked inhibition of bacterial colonization on enamel surfaces than plac ebo paste lacking this antimicrobial agent. These results indicate tha t the toothpaste formulation is compatible with chlorhexidine. It is c oncluded that the in vitro model developed in this study is suitable f or the testing of the antiplaque activity of antimicrobial agents, par ticularly when in a semisolid form such as in a toothpaste.