title: A 20-year retrospective survival study of fixed partial dentures.
abstract: OBJECTIVE
  This study of fixed partial dentures (FPDs) evaluated the long-term efficacy and determined frequencies and causes of failures.
  
  
  METHODS
  A total of 322 FPDs in 193 patients, fabricated at an undergraduate university clinic, were evaluated over a 20-year period. All patients were invited to participate in a supportive maintenance program. Failures of the FPDs were divided into irreversible complications (loss of FPD/abutment) and reversible complications (FPD intact after conservative treatment) and into biologic and technical/patient-related failures.
  
  
  RESULTS
  The Kaplan-Meier survival rate after 20 years was 66.2%. Statistically significant differences in survival rates were found between FPDs without post-and-core abutment teeth as compared to FPDs with at least one post-and-core abutment tooth (P = .002) and for vital abutments versus post-and-core abutments (P = .001), but significant differences were not found between restorations in the maxilla and mandible (P = .27). Caries and loss of retention were the main reasons for failure and accounted for 61% of the failures.
  
  
  CONCLUSIONS
  The survival of FPDs by undergraduate students at a university clinic during a 20-year period was comparable to the results published by university departments or general practitioners. Occurrence of a previously reversible complication is a predictive factor for an irreversible complication later on. A reversible complication within the first 2 years will probably lead to an early irreversible complication.
authors.affiliation: Centre for Special Care, PaeCaMed Research, Unit of Gnathology and Temporomandibular Disorders, 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: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000044:Dental Abutments; D003731:Dental Caries / Q000150:complications; D003774:Dental Plaque Index; D019232:Dental Restoration Failure; D003781:Denture Retention; D003830:Denture, Partial, Fixed; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D010512:Periodontal Index; D011176:Post and Core Technique; D011476:Prosthodontics / Q000193:education; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016019:Survival Analysis