title: Single-tooth replacement: is a 3-unit fixed partial denture still an option? A 20-year retrospective study.
abstract: OBJECTIVE
  This study of 3-unit fixed partial dentures (FPDs) evaluated the long-term efficacy and determined the frequencies and causes of failures.
  
  
  METHODS
  A total of 134 FPDs made in an undergraduate university clinic for 98 patients were evaluated over a 20-year period. All patients were offered a supportive maintenance program. Failures of the FPDs were divided into irreversible (loss of FPDs) or reversible (FPDs intact after conservative treatment) complications and into biologic and technical/patient-related failures.
  
  
  RESULTS
  The overall survival rate was 73.1% after 20 years. There was a statistically significant difference (P = .036) between the survival rates in the mandible for the vital group (96.3%) versus the root canal-treated group (69.3%). Comparing the survival rate in the vital group for the restorations in the maxilla (70.2%) versus the mandible (96.3%), a statistically significant difference (P = .045) was found. The survival rate after 20 years for the 3-unit FPDs (73.1%) was significantly different from that of the FPDs with more than 3 units (61.5%) (P = .026). The main reason for failure was caries (38.1%).
  
  
  CONCLUSIONS
  The survival of 3-unit FPDs over a 20-year period is favorable and should be compared with other single-tooth replacement treatment options. There is an indication that the occurrence of a reversible complication has a predictive value for an irreversible complication later on.
authors.affiliation: Department of Fixed Prosthodontics and Periodontology 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
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000044:Dental Abutments; D003731:Dental Caries / Q000150:complications; D019250:Dental Implants, Single-Tooth; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003779:Denture Design; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D008875:Middle Aged; D012189:Retrospective Studies; D012390:Root Canal Therapy; D016019:Survival Analysis; D016896:Treatment Outcome