title: Effect of chlorhexidine on multi-species biofilms.
abstract: With human saliva as an inoculum, microcosm dental plaques were grown on dental amalgam in a constant-depth film fermentor (CDFF) in the presence (suc +ve) and absence (suc -ve) of sucrose. The biofilms were then exposed to 0.2% chlorhexidine gluconate (CHG) for 1, 5, or 60 min and the survivors enumerated. Suc +ve biofilms had higher proportions of streptococci but lower proportions of veillonellae than suc -ve biofilms. Exposure to CHG for 1 min reduced the viable count of suc -ve and suc +ve biofilms by 53% and 89% respectively. In both cases, reductions were mainly attributable to killing of streptococci and actinomyces. After 60 min of exposure, 4% of the bacteria in the suc -ve and 2% in the suc +ve biofilms remained viable. This study has shown that large numbers of bacteria in microcosm dental plaques can survive a 1-min exposure to 0.2% CHG and that even after a 60-min exposure, substantial numbers of bacteria remain viable.
authors.affiliation: Department of Microbiology, Eastman Dental Institute, University of London, 256 Grays Inn Road, London WC1X 8LD, UK.
authors.forename: M
authors.initials: M
authors.lastname: Wilson
authors.forename: H
authors.initials: H
authors.lastname: Patel
authors.forename: J H
authors.initials: JH
authors.lastname: Noar
mesh_terms: D001419:Bacteria / Q000187:drug effects*; D018441:Biofilms; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003773:Dental Plaque / Q000382:microbiology*; D004202:Disinfectants / Q000494:pharmacology*; D006801:Humans; D013395:Sucrose / Q000494:pharmacology
chemical_list: D004202:Disinfectants; D013395:Sucrose; C010882:chlorhexidine gluconate; D002710:Chlorhexidine