title: An 18-year retrospective survival study of full crowns with or without posts.
abstract: OBJECTIVE
  This study of full crowns investigated long-term survival in relationship to biologic and technical variables.
  
  
  METHODS
  A total of 1,037 full crowns in 456 patients, made in an undergraduate university clinic, were evaluated over an 18-year period. All patients were offered a supportive maintenance program. Failures of full crowns were classified as irreversible (loss of full crown and/or tooth) or reversible (full crown intact after conservative treatment) complications and as biologic or technical/patient-related failures.
  
  
  RESULTS
  The Kaplan-Meier survival rate after 18 years was 78%. No statistically significant differences were found between restorations in the maxilla and mandible (P= .150); between restorations on molars, premolars, and anterior teeth (P = .671); and between restorations on posts and cores compared to restorations without posts and cores (P = .602). For the surviving restorations, the improved plaque score over time was statistically significant (P = .001). Biologic failures (66.4%) resulting in removal were more common than technical and patient-related failures (33.6%). Caries was the most frequent reason for failure (irreversible complication).
  
  
  CONCLUSIONS
  The survival of full crowns made in an undergraduate university clinic during an 18-year period is comparable to the results published by university departments or private practitioners. Plaque scores and bleeding on probing were not directly related to failures. Occurrence of a previously reversible complication is a predicting factor for an irreversible complication. A reversible complication within the first 2 years will probably lead to an early irreversible complication.
authors.affiliation: Dental School, Faculty of Medicine and Health Sciences, Ghent University, Belgium. Hein.Debacker@skynet.be
authors.forename: Hein
authors.initials: H
authors.lastname: De Backer
authors.forename: Georges
authors.initials: G
authors.lastname: Van Maele
authors.forename: Nathalie
authors.initials: N
authors.lastname: De Moor
authors.forename: Linda
authors.initials: L
authors.lastname: Van den Berghe
authors.forename: Jan
authors.initials: J
authors.lastname: De Boever
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003442:Crowns; D003731:Dental Caries / Q000150:complications; D003774:Dental Plaque Index; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016876:Metal Ceramic Alloys; D008875:Middle Aged; D010510:Periodontal Diseases / Q000150:complications; D010512:Periodontal Index; D011176:Post and Core Technique; D011476:Prosthodontics / Q000193:education; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D016876:Metal Ceramic Alloys