Antimicrobial efficacy of commercial dentifrices with triclosan or stannous fluoride

Abstract number: R2257

Haraszthy V., Zambon J., Sreenivasan P., DeVizio W.

Dentifrices with antimicrobials augment mechanical control of bacteria in oral biofilms and provide important clinical benefits such as reductions in gingivitis.

Objectives: This study assessed antimicrobial effects of commercial dentifrices with triclosan/copolymer (Colgate Total; TCN/copolymer), stannous fluoride (Crest Pro-Health; SnF2) or fluoride (Crest Cavity Protection; F). Antimicrobial effects were determined on a battery of 17 oral and non-oral bacterial strains representative of species in the normal oral cavity, in dental caries, in periodontal disease, and in halitosis. An ex-vivo test examined the effects of dentifrices on supragingival plaque from 10 adults as representative of the effects on bacteria in naturally-occurring biofilms.

Methods: Antimicrobial effects on 17 bacterial strains were determined by broth-based procedures for minimal inhibitory concentrations (MIC's). The lowest concentration of dentifrice inhibiting microbial growth after incubation is reported. For the ex-vivo study, dental plaque was collected from all teeth of the 10 subjects. Plaque samples were dispersed and serial dilutions plated on solid media containing different concentrations of each dentifrice and on control media without dentifrice. Bacterial colonies were enumerated following incubation.

Results: The TCN/copolymer dentifrice demonstrated the lowest MIC's. Substantial inhibition of oral Gram-negative bacteria (such as Veillonella sp. and periodontal pathogens including Aggregatibacter actinomycetemcomitans, Eikenella corrodens, and Fusobacterium nucleatum) and Gram-positive bacteria (Streptococcus sp.) was observed by the TCN/copolymer dentifrice. Analyses of the ex-vivo studies by 2-way ANOVA with subjects and dentifrice in the model demonstrated significant effects by the dentifrices (p < 0.0005). Post-hoc Tukey multiple comparison tests indicate significantly higher inhibition by TCN (>80%) than by either of the other dentifrices (p < 0.00005). No significant differences were observed between the SnF2 and F toothpastes (p = 0.99).

Conclusions: Results demonstrate significantly higher antimicrobial effects from the TCN/copolymer dentifrice against a panel of bacteria compared to the SnF2 and F dentifrices. TCN/copolymer dentifrice resulted in significantly higher ex-vivo inhibition of dental plaque bacteria in naturally-occurring biofilms compared to the other dentifrices (p < 0.0005).