title: Periapical changes following root-canal treatment observed 20-27 years postoperatively.
abstract: OBJECTIVE
  The aim of the present study was to identify periapical changes 20-27 years after root-canal treatment.
  
  
  METHODS
  The periapical condition of 265 roots filled by undergraduate students was evaluated in two series of intraoral radiographs taken 10-17 and 20-27 years after treatment. Roots (72) not recorded with a normal periapical situation on both occasions by two observers, were re-evaluated by other two examiners, separately and jointly. Final decisions about diagnoses were made by all four examiners. A strict definition was used for the identification of cases with an unfavourable outcome.
  
  
  RESULTS
  Favourable outcomes were observed in 6.4% of the roots that had radiolucencies at the 10-17-year follow-up. Periapical radiolucencies after 20-27 years appeared in 1.5% of all other roots. The radiographic failure frequency for the total material was 4.9%. The percentage of cases with normal periapical findings at the final follow-up was 86.4%, whilst 8.7% were recorded with increased width of the apical periodontal space. Delayed healing owing to surplus root-filling material explained nearly all of the cases with favourable outcome assessed many years after treatment.
  
  
  CONCLUSIONS
  Late periapical changes, with more successes than failures, were recorded when a 10-17-year follow-up period after root-canal treatment was extended for another 10 years.
authors.affiliation: Department of Odontology-Endodontics, School of Dentistry, University of Bergen, Arstadveien 17, N-5009 Bergen, Norway.
authors.forename: O
authors.initials: O
authors.lastname: Molven
authors.forename: A
authors.initials: A
authors.lastname: Halse
authors.forename: I
authors.initials: I
authors.lastname: Fristad
authors.forename: D
authors.initials: D
authors.lastname: MacDonald-Jankowski
mesh_terms: D005500:Follow-Up Studies; D006801:Humans; D015588:Observer Variation; D010483:Periapical Diseases / Q000000981:diagnostic imaging; D010486:Periapical Tissue / Q000000981:diagnostic imaging*; D010513:Periodontal Ligament / Q000000981:diagnostic imaging; D011670:Pulpectomy; D011859:Radiography; D012387:Root Canal Filling Materials; D018915:Root Canal Preparation; D012390:Root Canal Therapy; D014092:Tooth Root / Q000000981:diagnostic imaging; D017211:Treatment Failure; D016896:Treatment Outcome; D014945:Wound Healing
chemical_list: D012387:Root Canal Filling Materials