title: Effectiveness of a calcium hydroxide and chlorhexidine digluconate mixture as disinfectant during retreatment of failed endodontic cases.
abstract: OBJECTIVE
  The purpose of this in vivo investigation is to compare the effect of a slurry of Ca(OH)2 mixed in aqueous 2% chlorhexidine (CHX) versus aqueous Ca(OH)2 slurry alone on the disinfection of the pulp space of failed root-filled teeth during endodontic retreatment.
  
  
  METHODS
  Forty single-rooted previously root-filled teeth with associated periradicular lesions were included. The teeth were nonsurgically retreated and medicated over 3 treatment visits with 7-10-day intervals with either Ca(OH)2 in water or Ca(OH)2 in 2% aqueous CHX. Root canal cultures were collected in fluid thioglycollate, and bacterial growth was assessed by turbidity daily for 1 week, then weekly for an additional 3 weeks. The presence of enterococci in the root canals at the initial treatment session was determined.
  
  
  RESULTS
  Of the total sample population, 12 of 40 (30%) were positive for bacteria before root filling. The control medication disinfected 12 of 20 (60%) teeth including 2 of 4 teeth originally diagnosed with enterococci. The experimental medication resulted in disinfected 16 of 20 (80%) teeth at the beginning of the third appointment. None of the teeth originally containing enterococci showed remaining growth. This difference between the overall positive cultures was not statistically significant (P > .05).
  
  
  CONCLUSIONS
  Canal dressing with a mixture of 2% CHX and Ca(OH)2 slurry is as efficacious as aqueous Ca(OH)2 on the disinfection of failed root-filled teeth.
authors.affiliation: Department of Endodontology, School of Dental Medicine, University of Connecticut, Farmington, Conn, USA. josephzerella@yahoo.com
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Zerella
authors.forename: Ashraf F
authors.initials: AF
authors.lastname: Fouad
authors.forename: Larz S W
authors.initials: LS
authors.lastname: Spångberg
mesh_terms: D000328:Adult; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002126:Calcium Hydroxide / Q000494:pharmacology*; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003786:Dental Pulp Cavity / Q000382:microbiology; D019232:Dental Restoration Failure; D013293:Enterococcus faecalis / Q000187:drug effects; D006801:Humans; D010485:Periapical Periodontitis / Q000628:therapy; D019233:Retreatment; D012388:Root Canal Irrigants / Q000494:pharmacology*; D012390:Root Canal Therapy; D016037:Single-Blind Method
chemical_list: D000891:Anti-Infective Agents, Local; D012388:Root Canal Irrigants; C010882:chlorhexidine gluconate; D002126:Calcium Hydroxide; D002710:Chlorhexidine