title: The effect of a polyhexamethylene biguanide mouthrinse compared to an essential oil rinse and a chlorhexidine rinse on bacterial counts and 4-day plaque regrowth.
abstract: OBJECTIVE
  For various clinical applications, polyhexamethylene biguanide hydrochloride (PHMB) has been used for many years as an antiseptic in medicine. Recently, a 0.04% PHMB mouthwash was shown to inhibit plaque regrowth and to reduce oral bacterial counts. In this study, a 0.12% PHMB mouthrinse (A) was compared with a negative control placebo rinse (10% ethanol, flavour) (B), a positive control 0.12% chlorhexidine rinse (C), and a commercially available mouthrinse containing essential oils (Listerine) (D).
  
  
  METHODS
  The study was a double-blind, randomised 4-replicate 4 x 4 Latin square cross-over design in which plaque regrowth was measured. The in vivo antibacterial effect was assessed by taking bacterial counts from the tooth surface and mucosa 4 h after the first rinse with the preparations on day 1 and prior to the clinical examination on day 5. 16 volunteers participated and, on day 1 of each study period, were rendered plaque-free, ceased toothcleaning, and rinsed 2x daily with the allocated mouthrinse. On day 5, plaque was scored and smears were collected according to the protocol. Washout periods were 9 days. Data were analysed using ANOVA with Bonferroni HSD adjustment for multiple comparisons (significance level alpha=0.05).
  
  
  RESULTS
  The 0.12% PHMB mouthrinse (A) was significantly more effective in inhibiting plaque than the placebo (B) but no significant differences could be observed between A and 0.12% chlorhexidine (C), or between A and Listerine (D). Bacterial count reductions on the tooth surface with PHMB (A) were significantly greater compared to the placebo (B) after 4 h and significantly greater compared to B and D after 5 days. Chlorhexidine (C) was more effective than A after 5 days. On the mucosa, chlorhexidine (C) was significantly more effective in reducing bacterial counts than the other 3 treatments at both time points investigated. PHMB (A) was significantly more effective in reducing bacterial counts than the placebo (B) after 4 h and after 5 days, and than D after 4 h.
  
  
  CONCLUSIONS
  Consistent with a previous study, a PHMB mouthrinse was shown to inhibit plaque recolonisation and to reduce oral bacterial counts, indicating that PHMB may find applications in the prevention of plaque-associated diseases.
authors.affiliation: Department of Operative Dentistry, Periodontology, and Paediatric Dentistry, School of Dentistry, University of Greifswald, Germany. rosin@uni-greifswald.de
authors.forename: Michael
authors.initials: M
authors.lastname: Rosin
authors.forename: A
authors.initials: A
authors.lastname: Welk
authors.forename: T
authors.initials: T
authors.lastname: Kocher
authors.forename: A
authors.initials: A
authors.lastname: Majic-Todt
authors.forename: A
authors.initials: A
authors.lastname: Kramer
authors.forename: F A
authors.initials: FA
authors.lastname: Pitten
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D001645:Biguanides / Q000008:administration & dosage / Q000627:therapeutic use*; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D018592:Cross-Over Studies; D003773:Dental Plaque / Q000382:microbiology / Q000517:prevention & control*; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D009061:Mouth Mucosa / Q000382:microbiology; D009067:Mouthwashes / Q000627:therapeutic use*; D016011:Normal Distribution; D009822:Oils, Volatile / Q000008:administration & dosage / Q000627:therapeutic use*; D010919:Placebos; D015203:Reproducibility of Results; D012459:Salicylates / Q000008:administration & dosage / Q000627:therapeutic use*; D013223:Statistics as Topic; D013729:Terpenes / Q000008:administration & dosage / Q000627:therapeutic use*; D014070:Tooth / Q000382:microbiology
chemical_list: D000891:Anti-Infective Agents, Local; D001645:Biguanides; D004338:Drug Combinations; D009067:Mouthwashes; D009822:Oils, Volatile; D010919:Placebos; D012459:Salicylates; D013729:Terpenes; C031233:polihexanide; C057473:Listerine; D002710:Chlorhexidine