title: Antimicrobial activity of short- and medium-term applications of polyhexamethylene biguanide, chlorhexidine digluconate and calcium hydroxide in infected immature bovine teeth in vitro.
abstract: OBJECTIVE
  To compare the antimicrobial activity of polyhexamethylene biguanide (Prontosan wound gel, Pr) and chlorhexidine digluconate (CHX) after short- and medium-term application with the disinfection ability of calcium hydroxide (Ca) in a model using immature bovine teeth.
  
  
  METHODS
  Sixty immature bovine roots were infected with Enterococcus faecalis and randomly assigned to six groups (n = 10). Disinfectants were applied into the root canal for 10 min (CHX-10 min and Pr-10 min) or 7 days (CHX-7d, Pr-7d and Ca-7d(g) ). In the negative control group (Co-n), no disinfectant was used. Dentine samples were collected, and the total count of bacteria and colony-forming units were determined. The log10 -transformed Colony-forming units (CFU) data were analysed using a Kruskal-Wallis test with post hoc Wilcoxon multiple-comparison tests.
  
  
  RESULTS
  The application of disinfectants led to a significant reduction in CFUs in all groups compared with group Co-n. When compared to Ca-7d(g) , CHX-7d (P = 0.290), CHX-10 min (P = 0.963) and Pr-7d (P = 0.095) revealed no significant differences. Pr-10 min had a significantly higher CFU value than Ca-7d(g) (P = 0.0004), CHX-10 min (P = 0.0009) and Pr-7d (P = 0.0006).
  
  
  CONCLUSIONS
  Within the limitations of this study, sufficient antimicrobial effect may be reached by a short-term application of CHX. For the application of 1% Prontosan wound gel, a medium-term use (7 day) is required, while short-term use (10 min) is less effective.
authors.affiliation: Department of Periodontology, Endodontology and Cariology, University of Basel, Basel, Switzerland.
authors.forename: Lucia K
authors.initials: LK
authors.lastname: Zaugg
authors.forename: Nicola U
authors.initials: NU
authors.lastname: Zitzmann
authors.forename: Irmgard
authors.initials: I
authors.lastname: Hauser-Gerspach
authors.forename: Tuomas
authors.initials: T
authors.lastname: Waltimo
authors.forename: Roland
authors.initials: R
authors.lastname: Weiger
authors.forename: Gabriel
authors.initials: G
authors.lastname: Krastl
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D001645:Biguanides / Q000008:administration & dosage*; D002126:Calcium Hydroxide / Q000008:administration & dosage*; D002417:Cattle; D002710:Chlorhexidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D015169:Colony Count, Microbial; D066298:In Vitro Techniques; D007180:Incisor / Q000382:microbiology
chemical_list: D000890:Anti-Infective Agents; D001645:Biguanides; C031233:polihexanide; C010882:chlorhexidine gluconate; D002126:Calcium Hydroxide; D002710:Chlorhexidine
keywords: Enterococcus faecalis; disinfection; immature teeth; root canal dressing