Presentation Blocks: 03-23-2018 - Friday - 11:00 AM - 12:15 PM

Title: A Multi-criterion Antimicrobial Assessment of a Chlorhexidine Mouthwash


Grace Haddad, The University of Manchester
Ruth Ledder, The University of Manchester
Prem Sreenivasan (Presenter)
Colgate-Palmolive, Co.

Andrew McBain, The University of Manchester


Objectives: Controlling the growth and metabolism of oral bacteria reduces the accumulation of dental plaque and associated metabolic products representing an important component of oral hygiene. This study utilized a number of experimental approaches to examine the antibacterial effects of a mouthwash formulated with 0.12% (v/v) chlorhexidine (marketed as Colgate PerioGard (PG)) in comparison to a fluoride control rinse (Colgate FluoriGard (FL).

Methods: The rapid antimicrobial effects of each mouthwash against Actinomyces viscosus were evaluated using a cell viability indicator dye which was also utilized to determine the minimum inhibitory concentration (MIC) of each mouthwash against Streptococcus mutans. The acidogenesis-mitigation effect for treatments was defined as the minimum acid neutralizing concentration (MNC) for S. mutans and evaluated by a previously described assay that utilized a pH indicator. A novel fluorescence-based sugar assay examined Minimum Sugar Metabolism Inhibitory Concentrations (MiSMIC) for S. mutans.

Results: PG demonstrated rapid inactivation of Actinomyces viscosus in comparison to FL with viability values of 0.02 for PG and 0.74 for FL. Additionally, the MIC values against S. mutans were <0.024% (v/v) for PG and >50% (v/v) for FL. Acidogenesis-mitigation effects represented by MNC values for PG and FL were <0.024% (v/v) and 25% (v/v) respectively. MiSMIC outcomes for PG were <0.024% (v/v) and 0.694% (v/v) for FL.

Conclusions: Together, these results demonstrate significant effects of the mouthwash formulated with 0.12% chlorhexidine for immediate antimicrobial effects on bacteria, inhibition of microbial acid production and sugar metabolism in comparison to a mouthwash formulated with fluoride. Results from this investigation provide additional rationale for the effectiveness of chlorhexidine for oral hygiene.


Poster Session

11:00 am–12:15 pm Mar 23 (US - Eastern)

CC, Hall B/C