title: Radiographic evaluation of periapical healing after obturation of infected root canals: an in vivo study.
abstract: OBJECTIVE
  To radiographically compare periapical repair of roots with infected root canals obturated in one-step or with calcium hydroxide (Ca(OH)2) intracanal medication in two steps.
  
  
  METHODS
  Standardized preoperative periapical radiographs were taken of 72 roots of vital dogs' teeth. All roots were then aseptically instrumented to ISO size 45. As negative controls, 12 roots were aseptically obturated. The remaining roots were infected with dental plaque and closed. Six weeks later, apical periodontitis was radiographically confirmed in the infected roots. The roots were divided into the following groups: group 1, one-step (n = 24); roots were irrigated with 10 cc saline, obturated, and permanently restored. Group 2, Ca(OH)2 (n = 24); roots were treated as in group 1, except that after saline irrigation Ca(OH)2 medicament was placed in the canal 1 week before obturation. Group 3, positive control (n = 12); the roots were irrigated with saline, access permanently closed but canals not obturated. Group 4, negative control (n = 12); previously aseptically obturated roots were permanently restored. After 6 months, standardized postoperative radiographs were obtained. Three independent evaluators blinded to the treatment groups evaluated the preoperative and postoperative radiographs. The evaluators were instructed to rate each root, based on changes on the radiographs, as failed, improved or healed.
  
  
  RESULTS
  Radiographically, the percentage of cases that completely healed were similar for the one-step and Ca(OH)2 groups (35.3% vs. 36.8%). However, the Ca(OH)2 group had fewer failed cases (15.8% vs. 41.2%) and more improved cases (47.4% vs. 23.5%) than the one-step group.
  
  
  CONCLUSIONS
  Power statistics demonstrated that at 43 cases per group, Ca(OH)2 treatment would be statistically superior to one-step treatment. We consider this number to be clinically important.
authors: Department of Endodontics, University of North Carolina, Chapel Hill, North Carolina, USA.
authors: N
authors: N
authors: Katebzadeh
authors: A
authors: A
authors: Sigurdsson
authors: M
authors: M
authors: Trope
mesh_terms: D000818:Animals; D002126:Calcium Hydroxide / Q000627:therapeutic use; D016009:Chi-Square Distribution; D003773:Dental Plaque / Q000382:microbiology; D003788:Dental Pulp Diseases / Q000000981:diagnostic imaging / Q000382:microbiology* / Q000628:therapy; D004285:Dogs; D005500:Follow-Up Studies; D008768:Methylmethacrylates / Q000627:therapeutic use; D015588:Observer Variation; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging / Q000628:therapy; D010486:Periapical Tissue / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011859:Radiography; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D012388:Root Canal Irrigants / Q000627:therapeutic use; D012389:Root Canal Obturation; D016037:Single-Blind Method; D013223:Statistics as Topic; D016896:Treatment Outcome; D014945:Wound Healing; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
chemical_list: D008768:Methylmethacrylates; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D015035:Zinc Oxide-Eugenol Cement; C031667:IRM cement; D002126:Calcium Hydroxide