Reduction of salivary S. aureus and mutans group streptococci by a preprocedural chlorhexidine rinse and maximal inhibitory dilutions of chlorhexidine and cetylpyridinium.
OBJECTIVE
Staphylococcus aureus and mutans group streptococci can cause, among many other diseases, infective endocarditis and postoperative infections. The reduction of the number of these microorganisms in the oral cavity prior to surgical procedures has been related to a decreased incidence of such occurrences. The aim of this study was to evaluate the effect of a single preprocedural rinse with 0.12% chlorhexidine solution (Periogard) on the salivary counts of S aureus and mutans group streptococci and determine maximal inhibitory dilutions (MID) of this and 0.05% cetylpyridinium chloride solution (Cepacol).


METHODS
Saliva was collected from 60 patients before and after 30-second mouthrinses with chlorhexidine and cultured in appropriate media. The number of microorganisms was calculated based on the colony-forming units (CFUs). For the in vitro MID determination, 25 strains of S aureus were seeded in the media containing one of the sequential dilutions of both antiseptics.


RESULTS
S aureus, Streptococcus mutans, and Streptococcus sobrinus were initially isolated from 45%, 63%, and 28% of the patients, respectively. After rinsing with chlorhexidine, the reductions in the CFUs were above 99% for all the studied microorganisms. In the MID determination, all isolates were inhibited with 1/20 and 1/80 dilutions of cetylpyridinium and chlorhexidine, respectively. Dose-response curves were obtained for both antiseptics.


CONCLUSIONS
Single preprocedural chlorhexidine mouthrinse is effective in reducing salivary microorganisms to levels currently considered safe to perform invasive procedures, and it is still effective in a 1:80 dilution.
de Albuquerque
Rubens F
RF
Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. ralbuque@forp.usp.br
Head
Timothy W
TW
Mian
Henis
H
Rodrigo
André
A
Müller
Katia
K
Sanches
Karina
K
Ito
Izabel Yoko
IY
D000293:Adolescent; D000328:Adult; D000368:Aged; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis / Q000379:methods*; D002594:Cetylpyridinium / Q000008:administration & dosage*; D002710:Chlorhexidine / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009067:Mouthwashes / Q000008:administration & dosage*; D019647:Oral Surgical Procedures; D012463:Saliva / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects; D013530:Surgical Wound Infection / Q000517:prevention & control
D000891:Anti-Infective Agents, Local; D009067:Mouthwashes; D002594:Cetylpyridinium; D002710:Chlorhexidine