Effect of chlorhexidine on multi-species biofilms.
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.
Wilson
M
M
Department of Microbiology, Eastman Dental Institute, University of London, 256 Grays Inn Road, London WC1X 8LD, UK.
Patel
H
H
Noar
J H
JH
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
D004202:Disinfectants; D013395:Sucrose; C010882:chlorhexidine gluconate; D002710:Chlorhexidine