The study of biofilm structure and function mandates the use of model syste
ms for which a host of environmental variables can be rigorously controlled
. We describe a model of supragingival plaque containing Actinomyces naeslu
ndii, Veillonella dispar, Fusobacterium nucleatum, Streptococcus sobrinus,
and Streptococcus oralis wherein cells are cultivated anaerobically in a sa
liva-based medium on hydroxyapatite discs coated with a salivary pellicle,
with material and pieces of apparatus common to all microbiology laboratori
es. After 0.5 hr, 16.5 hrs, 40.5 hrs, and 64.5 hrs, the composition of adhe
rent biofilms was analyzed by culture techniques, live/dead fluorescence st
aining, and confocal laser scanning microscopy. Repeated independent trials
demonstrated the repeatability of biofilm formation after 40.5 hrs and 64.
5 hrs. Brief exposures of biofilms to chlorhexidine or Triclosan produced l
osses in viability similar to those observed in vivo. This biofilm model sh
ould prove very useful for pre-clinical testing of prospective anti-plaque
agents at clinically relevant concentrations.