title: Substantive antimicrobial activity in chlorhexidine-treated human root dentin.
abstract: OBJECTIVE
  The aim of this in vitro study was to assess the substantive antimicrobial activity of different medicaments in human root dentin.
  
  
  METHODS
  Canals of 98 roots were enlarged to standard size and medicated for 7 days with the following: (1) 2% chlorhexidine (CHX) gel, (2) 0.2% CHX gel, (3) 2% CHX solution, (4) Ca(OH)(2), (5) Ca(OH)(2)+ 0.2% CHX gel, (6) 2% CHX solution + a 25% CHX-containing controlled-release device, (7) saline, and (8) gel vehicle. After medication, canals were inoculated with Enterococcus faecalis for 21 days. Dentin samples were collected with Gates-Glidden burs into brain heart infusion broth, and bacterial growth was assessed with spectrophotometric analysis of optical density after 72 hours of incubation.
  
  
  RESULTS
  Mean optical densities were significantly lower for groups with 2% CHX (1, 3, and 6) when compared with those of the controls (P < .05, analysis of variance with the Tukey test). Other groups did not differ significantly from the controls.
  
  
  CONCLUSIONS
  Canal dressing for 1 week with 2% CHX may provide residual antimicrobial activity against E faecalis.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, University of Toronto, Ontario, Canada. bettina.basrani@dal.ca
authors.forename: Bettina
authors.initials: B
authors.lastname: Basrani
authors.forename: J Miguel
authors.initials: JM
authors.lastname: Santos
authors.forename: Leo
authors.initials: L
authors.lastname: Tjäderhane
authors.forename: Helen
authors.initials: H
authors.lastname: Grad
authors.forename: Omer
authors.initials: O
authors.lastname: Gorduysus
authors.forename: Junfu
authors.initials: J
authors.lastname: Huang
authors.forename: Herenia P
authors.initials: HP
authors.lastname: Lawrence
authors.forename: Shimon
authors.initials: S
authors.lastname: Friedman
mesh_terms: D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D002126:Calcium Hydroxide / Q000008:administration & dosage / Q000627:therapeutic use; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D003692:Delayed-Action Preparations; D003786:Dental Pulp Cavity / Q000187:drug effects*; D003804:Dentin / Q000187:drug effects*; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000187:drug effects / Q000254:growth & development; D005782:Gels; D006801:Humans; D055095:Optics and Photonics; D014677:Pharmaceutical Vehicles; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000627:therapeutic use*; D012965:Sodium Chloride; D012996:Solutions; D013053:Spectrophotometry; D013223:Statistics as Topic; D014092:Tooth Root / Q000187:drug effects*
chemical_list: D000891:Anti-Infective Agents, Local; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D005782:Gels; D014677:Pharmaceutical Vehicles; D012388:Root Canal Irrigants; D012996:Solutions; D012965:Sodium Chloride; D002126:Calcium Hydroxide; D002710:Chlorhexidine