Antibacterial efficacy of a cetylpyridinium chloride-based mouthrinse against Fusobacterium nucleatum and in vitro plaques.

PURPOSE: To assess the antimicrobial effects of a fluoride-free and alcohol-free mouthrinse containing 0.075% CPC (test rinse, TR) compared with an otherwise-identical CPC-free control rinse (CR). METHODS: Activity against laboratory cultures of Fusobacterium nucleatum, a bacterium associated with gingival disease, was determined using viable counting following 30-second exposures to TR and CR. Effects against intact saliva-derived plaque biofilms were quantified using confocal microscopy coupled with three-dimensional image analyses (viability profiling). RESULTS: Short exposures to TR caused significant inactivation of F. nucleatum, as determined by viable counting (c. 3 log reduction compared to the control rinse, P < 0.05). Confocal microscopy revealed extensive inactivation of complex oral biofilms following treatment with TR; biofilms were significantly less viable than those exposed to CR and three-dimensional images revealed extensive zones of dead bacteria even within plaque depths. In conclusion, this investigation demonstrates that the CPC-containing mouthrinse has significant antibacterial efficacy against oral bacteria associated with gingival disease and significantly inactivated plaque biofilm in comparison to a relevant control.