Direct measurement of the bactericidal effect of chlorhexidine on human dental plaque.
The purpose of the present study was to determine by means of a fluorescence test the ratio between vital and dead bacteria in dental plaque before and after 0.1% chlorhexidine rinses. Plaque was stained by fluoresceindiacetate (FDA), which gave a green color to the living micro-organisms, and by ethidiumbromide (EB), which introduced a red color into the nucleic acids of the dead bacteria. 1-, 2- and 3-day-old undisturbed plaque harbored 80 to 85% living micro-organisms. 1 h after chlorhexidine use, this % was reduced to a plateau of 19 to 34% of vital bacteria present in the sampled plaque. Between 6 and 8 h later, this % rose towards its original value. This study has shown that FDA/EB staining provides a method for direct measurement of bacteria vitality in dental plaque and, as such, can be of great value for testing the efficacy of various antiplaque agents.
Netuschil
L
L
Department of Conservative Dentistry, School of Dental Medicine, University of Tübingen, FRG.
Reich
E
E
Brecx
M
M
D000328:Adult; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003773:Dental Plaque / Q000188:drug therapy / Q000382:microbiology*; D004996:Ethidium; D005452:Fluoresceins; D006801:Humans; D008856:Microscopy, Fluorescence; D013194:Staining and Labeling / Q000379:methods
D005452:Fluoresceins; D004996:Ethidium; C010882:chlorhexidine gluconate; D002710:Chlorhexidine; C018506:diacetylfluorescein