title: Longitudinal study of the influence of removable partial denture and chemical control on the levels of Streptococcus mutans in saliva.
abstract: Some studies have evaluated the salivary levels of mutans streptococci (MS) in removable partial denture (RPD) users. Saliva samples (2.0 mL) were obtained from 31 patients in six periods: (T0): immediately before installation of RPD; (T8): 8 days after T0; (T48): 48 days after T0; (T92): 92 days after T0; (T140): 140 days after T0 and (T189): 189 days after T0. The samples were vortexed and serially diluted from 10(-1) to 10(-6) in 0.05 m phosphate buffer (pH 7.4). From each dilution, 0.025 mL was plated on Mitis Salivarius Bacitracin (MSB). The plates were incubated in 5% CO2 at 37 degrees C for 72 h. There was an increase (t-test, P < 0.05) in the number of MS between periods T0 and T48 (mean/s.d., CFU mL(-1) of saliva): T0: 2.26/4.43 x 10(6) and T48: 0.47/1.48 x 10(8). After this, intensive treatment with CHX was accomplished in 29 patients. Saliva samples were obtained after treatment in four periods: (T24 h): 24 h after T0; (T14): 14 days after T24 h; (T28): 28 days after T24 h, and (T63): 63 days after T24 h. The number of MS in saliva did not decrease (t-test, P > 0.05). A new CHX formulation was applied in 15 patients. Saliva samples were obtained in periods: (T0): before new CHX application; (T24 h): 24 h after T0 and (T82): 82 days after T0. The new CHX reduced MS levels in saliva: (mean/s.d., CFU mL(-1) of saliva): T0: 6.64/8.47 x 10(6) and T24 h: 3.2/4.27 x 10(5) (sign rank, P < 0.05). In conclusion, there was a significant increase in the number of MS in saliva after the installation of RPD. The intensive treatment with a properly formulated CHX was effective in the reduction of MS, between 24 h and 82 days after its application.
authors.affiliation: Department of Dental Materials and Prosthodontics, Faculty of Dentistry of Araçatuba, UNESP, Araçatuba, SP, Brazil.
authors.forename: E P
authors.initials: EP
authors.lastname: Rocha
authors.forename: S B
authors.initials: SB
authors.lastname: Francisco
authors.forename: A A
authors.initials: AA
authors.lastname: Del Bel Cury
authors.forename: J A
authors.initials: JA
authors.lastname: Cury
mesh_terms: D002710:Chlorhexidine / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D003832:Denture, Partial, Removable / Q000382:microbiology; D006801:Humans; D008137:Longitudinal Studies; D009067:Mouthwashes / Q000627:therapeutic use*; D012463:Saliva / Q000382:microbiology*; D013295:Streptococcus mutans
chemical_list: D009067:Mouthwashes; D002710:Chlorhexidine