ANTISEPTIC ACTIVITY OF SOME ANTIDENTAL PLAQUE CHEMICALS ON STREPTOCOCCUS-MUTANS BIOFILMS

S. mutans is one of the bacterial species involved in the initiation o f cariogenic dental plaque. In situ, antiseptic activity evaluation of dental plaque chemicals is fairly difficult. A dynamic biofilm model of S. mutans on Tygon(TM) support is suitable for the quantification o f antiseptic activity and the comparison of commercial chemical formul ations, submitted or not to the french standards and Pharmacopea. Some of these chemicals, especially quaternary ammonia solutions, do not r educe living bacteria counts by 10E5 as AFNOR specifies. In the case o f dental plaque, antiseptic activity is probably not the only relevant parameter : biofilm dissociation is rather more relevant because the dead or living bacteria adhere to the teeth, favouring the establishme nt of a new active biofilm. Two proceedings can be followed - support surface can be modified, or bacteria exopolvmers synthesis can be inhi bited to prevent cell adherence; - the disruption of the biofilm glyco calyx can be achieved with enzymes or surfactants.