title: Mouth-rinsing with chlorhexidine causes a delayed, temporary increase in the levels of oral viridans streptococci.
abstract: The indigenous oral flora of 27 volunteers was monitored longitudinally over a 4-week period. Bacteria attached on buccal epithelial cells were counted by microscopy. Salivary bacterial colonies and the presence of alpha-hemolysis were examined after aerobic culturing on blood agar plates. The buccal and salivary bacterial counts were stably maintained in most subjects in the two repeated base-line samplings taken at 1-week intervals. Rinsing with a chlorhexidine mouthwash 45 min before sampling dramatically reduced the amount of epithelial cell-adherent bacteria. One day after the chlorhexidine rinse, however, the numbers of the epithelial cell-adherent bacteria exceeded the base-line level, and a similar decrease-increase pattern of changes was detected for the salivary alpha-hemolytic streptococcal counts. The non-hemolytic salivary bacterial counts were not affected by chlorhexidine. Subsequent weekly samplings showed no difference from the base-line samplings. The chlorhexidine-induced, delayed increase of viridans streptococci on oral epithelial surfaces should be considered a possible risk factor in medically compromised patients.
mesh_terms: D000328:Adult; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015169:Colony Count, Microbial; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D009061:Mouth Mucosa / Q000382:microbiology; D009067:Mouthwashes / Q000494:pharmacology*; D012463:Saliva / Q000382:microbiology; D018709:Statistics, Nonparametric; D013291:Streptococcus / Q000187:drug effects*
chemical_list: D000891:Anti-Infective Agents, Local; D009067:Mouthwashes; C010882:chlorhexidine gluconate; D002710:Chlorhexidine