Objectives. The aim of this in vitro study was to evaluate the inhibitory effects of several commercially available antibacterial
oral rinses on S. mutans biofilm formation.
Methods. In this study, four commercial oral rinses produced in Korea containing different antibacterial substances (benzethonium
chloride, cetylpyridinium chloride, chlorhexidine, and essential oil) were selected for assessment. Sterile distilled water and 0.1%
chlorhexidine solution were used as a negative and a positive control, respectivery The planktonic S. mutans (107 CFU/ml) was
mixed with the experimental oral rinses for 1 minute and the live cells were counted as a colonies forming unit (CFU). Also,
the antibacterial effect of oral rinses were tested by a S. mutans biofilm model with the artificial saliva, THYE medium, and
hydroxyapatite (HA) discs. The S. mutans biofilm was formed on an HA disc coated with artificial saliva for 64 hours. The medium
was replaced every 24 hours, and the cultured biofilm was treated with each oral rinse for either 1 or 5 minutes, 3 times a day
for two days. Also, the number of live cells in the biofilm were counted and denoted as CFU.
Results. All four commercial oral rinses elicited significant antibacterial effects on planktonic S. mutans, showing more than 99%
of CFU reduction. However, only Hexamedine oral rinse primarily composed of chlorhexidine exhibited a significant antibacterial
effect on S. mutans biofilm.
Conclusions. The antibacterial effects of the commercial oral rinses were less pronounced in biofilm than in the planktonic cells,
and they varied among different products.