title: The impact of a low-frequency chlorhexidine rinsing schedule on the subgingival microbiota (the TEETH clinical trial).
abstract: BACKGROUND
  Information on the efficacy of chlorhexidine (CHX) rinsing on the subgingival microbiota is limited. This study tested if intermittent CHX rinsing over 5 years had an impact on the subgingival microbiota.
  
  
  METHODS
  Subgingival plaque samples were analyzed by the checkerboard DNA-DNA hybridization method in a double-blind randomized CHX rinse study.
  
  
  RESULTS
  A total of 210 subjects were included. The mean age of the subjects was 71.7 (+/- 4.1) years, and 56.2% were women. Evidence of alveolar bone loss was found in 39% of subjects. Bacterial loads were not correlated significantly with probing depth. At year 5, subjects in the CHX rinse group with no evidence of bone loss presented with lower total bacterial counts than control subjects with no bone loss. The levels of the following bacteria were significantly lower in the CHX group: Lactobacillus acidophilus (P <0.05), Eikenella corrodens (P <0.05), Fusobacterium nucleatum sp. nucleatum (P <0.01), Treponema denticola (P <0.05), Leptotrichia buccalis (P <0.05), and Eubacterium saburreum (P <0.05). No differences in bacterial loads were found between CHX and control rinse subjects with alveolar bone loss.
  
  
  CONCLUSIONS
  Older subjects with or without periodontitis carry a large variety of bacteria associated with periodontitis. Intermittent rinsing with CHX may provide a preventive benefit in reducing levels of bacteria but only in subjects without alveolar bone loss.
authors.affiliation: Department of Periodontology and Fixed Prosthodontics, Division of Oral Microbiology, School of Dental Medicine, University of Berne, Berne, Switzerland. rutger.persson@zmk
authors.forename: G Rutger
authors.initials: GR
authors.lastname: Persson
authors.forename: Justin
authors.initials: J
authors.lastname: Yeates
authors.forename: Rigmor E
authors.initials: RE
authors.lastname: Persson
authors.forename: Regula
authors.initials: R
authors.lastname: Hirschi-Imfeld
authors.forename: Marianne
authors.initials: M
authors.lastname: Weibel
authors.forename: H Asuman
authors.initials: HA
authors.lastname: Kiyak
mesh_terms: D000368:Aged; D016301:Alveolar Bone Loss / Q000473:pathology; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D002710:Chlorhexidine / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D016321:Dental Care for Aged / Q000379:methods*; D003773:Dental Plaque / Q000188:drug therapy* / Q000382:microbiology*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009067:Mouthwashes / Q000008:administration & dosage*; D018709:Statistics, Nonparametric
chemical_list: D000891:Anti-Infective Agents, Local; D004269:DNA, Bacterial; D009067:Mouthwashes; D002710:Chlorhexidine