title: Prevalence of mutans streptococci isolated from complete dentures and their susceptibility to mouthrinses.
abstract: The aims of this study were to evaluate the incidence of mutans streptococci (MS - sessile form) on complete maxillary dentures after use of a specific denture paste, and to determine the minimum inhibitory concentration (MIC) and maximum inhibitory dilution (MID) of 3 oral mouthrinses: Cepacol, Plax and Periogard. Seventy-seven complete denture wearers were randomly assigned into 2 groups, according to the product used for denture cleaning: Control group - conventional dentifrice (Kolynos-Super White); and Test group: experimental denture cleaning paste. Denture biofilm was collected at baseline and after 90 and 180 days after treatment by brushing the dentures with saline solution. After decimal serial dilution, samples were seeded onto agar sucrose bacitracin to count colonies with morphological characteristics of MS. MS identification was performed by the sugar fermentation tests. After this procedure, brain heart infusion broth (BHI) was added to oral mouthrinses (Plax, Cepacol e Periogard) and seeded on Petri dishes. The colonies were seeded using the Steers multiplier and, after the incubation, the MIC and MID of the mouthrinses were calculated. The results showed an incidence of 74.0% (n=57) of MS in the 77 complete dentures examined in the study, being 76.3% (n=29) of the Control group (conventional dentifrice) and 71.8% (28) of the Test group (experimental denture cleaning paste). In both groups, the number of positive cases for MS decreased from day 0 to day 180. In the Test group there was a slight decrease in the incidence of Streptococcus mutans 90 days after use of the experimental denture cleaning paste, which was not observed in the Control group. As regards to mouthrinses, for both groups, Periogard showed antimicrobial action with the highest dilution, followed by Cepacol and Plax. In conclusion, the incidence of MS in complete dentures was high and Periogard was the mouthrinse with the strongest antimicrobial action against MS. The experimental denture cleaning paste showed a slight action against S. mutans after 90 days of treatment.
authors.affiliation: Department of Dental Materials and Prosthodontics, Ribeirão Preto Dental School, University of São Paulo, SP, Brazil.
authors.forename: Rodrigo Fernando Gonçalves
authors.initials: RF
authors.lastname: André
authors.forename: Ingrid Machado de
authors.initials: IM
authors.lastname: Andrade
authors.forename: Cláudia Helena
authors.initials: CH
authors.lastname: Silva-Lovato
authors.forename: Helena de Freitas Oliveira
authors.initials: Hde F
authors.lastname: Paranhos
authors.forename: Fabiana Cristina
authors.initials: FC
authors.lastname: Pimenta
authors.forename: Izabel Yoko
authors.initials: IY
authors.lastname: Ito
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002594:Cetylpyridinium / Q000494:pharmacology; D002710:Chlorhexidine / Q000494:pharmacology; D015169:Colony Count, Microbial; D003820:Denture Cleansers; D003827:Denture, Complete, Upper / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007201:Indicator Dilution Techniques; D008297:Male; D008826:Microbial Sensitivity Tests; D009067:Mouthwashes / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects*; D014260:Triclosan / Q000494:pharmacology
chemical_list: D000891:Anti-Infective Agents, Local; D003820:Denture Cleansers; D009067:Mouthwashes; D014260:Triclosan; D002594:Cetylpyridinium; D002710:Chlorhexidine