The in vitro inhibition of microbial growth and plaque formation by surfactant drugs.

Several cationic, mixed and amphoteric surfactants were tested for their antimicrobial activity and ability to inhibit the formation of in vitro plaque by oral microorganisms. All had antimicrobial activity against Actinomyces viscosus. Actinomyces naeslundii and Streptococcus mutans. Cationic surfactants were comparable to chlorhexidine in antimicrobial activity but were less effective in inhibiting plaque formation. Amphoteric surfactants were less effective than other detergents in antibacterial activity and had very limited capacity for the inhibition of plaque formation. Comparison of drug structure provides evidence that surfactant substantivity to saliva-coated enamel is a cation active process. Saliva was found to have an antagonistic effect on the activity of cetylpyridinium chloride but not on Triburon.