title: Chlorhexidine substantivity on salivary flora and plaque-like biofilm: an in situ model.
abstract: OBJECTIVE
  To evaluate the in situ antibacterial activity of a mouthrinse with 0.2% Chlorhexidine (M-0.2% CHX) on undisturbed de novo plaque-like biofilm (PL-biofilm) and on salivary flora up to 7 hours after its application.
  
  
  METHODS
  A special acrylic appliance was designed, with 3 inserted glass disks on each buccal side, allowing for PL-biofilm growth. Fifteen healthy volunteers wore the appliance for 48 hours and then performed an M-0.2% CHX; disks were removed at 30 seconds and 1, 3, 5 and 7 hours after the mouth-rinsing. Applying a washout period, saliva samples were collected from each volunteer at 30 seconds and 1, 3, 5 and 7 hours after performing an M-0.2% CHX. The PL-biofilm and saliva samples were analysed by confocal laser scanning and epifluorescence microscopes, respectively.
  
  
  RESULTS
  At 30 seconds after M-0.2% CHX, the levels of viable bacteria detected in saliva were significantly lower than those observed in PL-biofilm. The difference in the percentage of live bacteria detected in saliva was significantly higher than that observed in PL-biofilm at 5 and 7 hours after M-0.2% CHX.
  
  
  CONCLUSIONS
  After a single mouthrinse of the 0.2% CHX formulation tested in the present study, the 2-day PL-biofilm presented a significantly higher resistance to this antiseptic in situ than that observed in salivary flora. However, this 0.2% CHX formulation showed a higher substantivity on PL-biofilm than on salivary flora at 5 and 7 hours after mouth-rinsing, which could be related to the slower growth rate of PL-biofilm and the possible reservoir function for antimicrobial agents associated with the undisturbed de novo PL-biofilm.
authors.affiliation: Oral Sciences Research Group, School of Medicine and Dentistry, Santiago de Compostela University, Santiago de Compostela, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: García-Caballero
authors.affiliation: Oral Sciences Research Group, School of Medicine and Dentistry, Santiago de Compostela University, Santiago de Compostela, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Quintas
authors.affiliation: Oral Sciences Research Group, School of Medicine and Dentistry, Santiago de Compostela University, Santiago de Compostela, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Prada-López
authors.affiliation: Oral Sciences Research Group, School of Medicine and Dentistry, Santiago de Compostela University, Santiago de Compostela, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Seoane
authors.affiliation: Periodontology Unit, UCL Eastman Dental Institute, London, United Kingdom.
authors.forename: Nikos
authors.initials: N
authors.lastname: Donos
authors.affiliation: Oral Sciences Research Group, School of Medicine and Dentistry, Santiago de Compostela University, Santiago de Compostela, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Tomás
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology*; D015169:Colony Count, Microbial; D018592:Cross-Over Studies; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D009055:Mouth / Q000382:microbiology; D009067:Mouthwashes; D012463:Saliva / Q000382:microbiology*
chemical_list: D000891:Anti-Infective Agents, Local; D009067:Mouthwashes; D002710:Chlorhexidine