In-vivo Anti-Microbial Effects of a 0.1% CPC Rinse

Objective: This research compared the in-vivo, antimicrobial effects of a 0.1% cetylpyridinium chloride (CPC) rinse to positive and negative rinse controls.

Method: This randomized, single-use, 3 periods, examiner-blind, 15 subject, cross-over trial compared the immediate and 4 hr. post use anti-microbial efficacy of an alcohol-free 0. 1% CPC rinse containing 1.5% hydrogen peroxide (Crest® Pro-Health Clinical) (CP) to negative (water - WA) and positive controls (essential oils rinse (EO) (Listerine® Cool Mint)).  10 ml oral lavage samples for microbial enumeration were taken at baseline (24 hr prior),immediately and 4 hr after treatment.  Treatments consisted of a single, 20 ml rinse of assigned mouthwash for 30 sec.  Appropriately diluted oral lavage samples were hand-plated onto Enriched Trypticase Soy Agar (ETSA), Enriched Trypticase Soy w/1% Nalidixic Acid Vancomycin Agar(ETSA-NV), and Enriched Trypticase Soy Agar w/Bismuth (ETSA-BA) and incubated under anaerobic conditions.  In addition, oral lavage samples were plated onto Trypticase Soy Agar (TSA) and incubated under aerobic conditions.  The 4 plating conditions correspond to Total Facultative Anaerobes, Total Gram Negative Anaerobes, Total Sulfide Producers, and Total Aerobes, respectively.  Microbial plate counts were transformed to log base 10 and analyzed using analysis of covariance (ANCOVA) for crossover studies.  There was a 1 week washout between periods.

Result: :   Both the CP and EO rinses showed significant bacterial reductions (p< 0.05) immediately and 4 hr post-treatment for the 4 bacterial classes enumerated versus WA.  In addition, the CP rinse was significantly (p <0.05) better than the EO rinse in bacterial reductions immediately after and 4 hr post treatment for all 4 bacterial groups.

Conclusion: The alcohol-free 0. 1% CPC rinse containing 1.5% hydrogen peroxide was observed to kill more bacteria immediately and 4 hr post-use than the positive control EO rinse.