Comparison of In Vitro Antibacterial Effects of Two Commercial Dentifrices

Chemical control of dental plaque is traditionally carried out using an antibacterial agent, such as triclosan, stannous fluoride or cetyl pyridinium chloride in a dentifrice or a mouthwash. Objective: This research evaluated the in vitro antibacterial efficacy of two commercial dentifrices; one containing 0.24% sodium fluoride/0.30% triclosan/2% gantrez, the other containing 0.45%stannous fluoride together with zinc lactate. Methods: In each test, saliva coated hydroxyapatite discs (HAPD) were treated with a slurry of one of the dentifrices for 30min, washed with water, and then transferred to a new tube containing a bacterial suspension adjusted to 0.2 OD at 610nm. The test samples were incubated at 37°C for different time intervals. The effects on three oral bacterial species, Actinomyces viscosus Streptococcus mutans and Fusobacterium nucleatum, and two different growth media, Trypticase Soy Agar (Becton, Dickinson and Company) and Biofilm Media, described by C.Y. Loo et al (J. of Bacteriology, 2000) were compared. After incubation, an aliquot of bacterial suspension was removed at 2, 4, 20, 24, 28, and 30 hours, respectively, and the optical density was measured. Results: Significantly higher in vitro anti-bacterial efficacy was observed under all experimental conditions and at most time points (4 hours and beyond) for the toothpaste containing triclosan/gantrez as compared to the toothpaste containing 0.45%stannous fluoride/zinc lactate. Significant differences were observed for all three bacterial species. Conclusion: The toothpaste containing 0.24% sodium fluoride/0.30%triclosan/2% gantrez demonstrated superior antibacterial effects in vitro as compared to the toothpaste containing 0.45% stannous fluoride and zinc lactate