title: A synergistic chlorhexidine/chitosan combination for improved antiplaque strategies.
abstract: BACKGROUND
  The minor efficacy of chlorhexidine (CHX) on other cariogenic bacteria than mutans streptococci such as Streptococcus sanguinis may contribute to uneffective antiplaque strategies.
  
  
  RESULTS
  In addition to CHX (0.1%) as positive control and saline as negative control, two chitosan derivatives (0.2%) and their CHX combinations were applied to planktonic and attached sanguinis streptococci for 2 min. In a preclinical biofilm model, the bacteria suspended in human sterile saliva were allowed to attach to human enamel slides for 60 min under flow conditions mimicking human salivation. The efficacy of the test agents on streptococci was screened by the following parameters: vitality status, colony-forming units (CFU)/ml and cell density on enamel. The first combination reduced the bacterial vitality to approximately 0% and yielded a strong CFU reduction of 2-3 log(10) units, much stronger than CHX alone. Furthermore, the first chitosan derivative showed a significant decrease of the surface coverage with these treated streptococci after attachment to enamel.
  
  
  CONCLUSIONS
  Based on these results, a new CHX formulation would be beneficial unifying the bioadhesive properties of chitosan with the antibacterial activity of CHX synergistically resulting in a superior antiplaque effect than CHX alone.
authors.affiliation: Department of Conservative Dentistry, School of Dental Medicine, University of Tuebingen, Germany. Evi.Decker@med.uni-tuebingen.de
authors.forename: E-M
authors.initials: EM
authors.lastname: Decker
authors.forename: C
authors.initials: C
authors.lastname: von Ohle
authors.forename: R
authors.initials: R
authors.lastname: Weiger
authors.forename: I
authors.initials: I
authors.lastname: Wiech
authors.forename: M
authors.initials: M
authors.lastname: Brecx
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects; D002614:Chelating Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D048271:Chitosan / Q000008:administration & dosage / Q000627:therapeutic use*; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D003743:Dental Enamel / Q000382:microbiology; D003773:Dental Plaque / Q000382:microbiology / Q000517:prevention & control*; D004338:Drug Combinations; D004357:Drug Synergism; D006801:Humans; D010865:Pilot Projects; D012463:Saliva / Q000382:microbiology; D012472:Salivation / Q000502:physiology; D013298:Streptococcus sanguis / Q000187:drug effects
chemical_list: D000891:Anti-Infective Agents, Local; D002614:Chelating Agents; D004338:Drug Combinations; D048271:Chitosan; D002710:Chlorhexidine