title: A retrospective evaluation of treatments with implant-supported maxillary overdentures.
abstract: BACKGROUND
  Considerably lower success rates have been presented for implant-supported overdentures in the maxilla compared with the mandible.
  
  
  OBJECTIVE
  The aim of the study was to report the outcome of implant-supported maxillary overdentures from one clinic.
  
  
  METHODS
  All patients treated with implant-supported maxillary overdentures in the Department of Prosthetic Dentistry, Central Hospital, Skövde, Sweden, between 1993 and 2002 were identified from patient charts and included in the study. All patients had a rigid cast gold alloy bar designed with ball attachments retaining an overdenture.
  
  
  RESULTS
  Twenty-seven subjects were included, of whom 13 were originally planned for overdenture treatment (group 1) and the other 14 for a fixed prosthesis (group 2). The mean observation period was 5.7 years for subjects in group 1 and 5.5 years for those in group 2. One hundred forty-five implants were placed, and the majority of the failures were diagnosed as early ones and were found in group 2. The cumulative implant survival rate after 5 years was 77% in group 1 and 46% in group 2. The probability of having implant failure was almost three times higher among subjects in group 2 compared with subjects in group 1. Most technical and biologic complications were related to the retention system.
  
  
  CONCLUSIONS
  Maxillary implant-supported overdentures show a high implant failure rate, but fewer implant failures occurred for patients originally planned for overdenture treatment.
authors.affiliation: Department of Prosthetic Dentistry, Central Hospital, Skövde, Sweden.
authors.forename: Christin
authors.initials: C
authors.lastname: Widbom
authors.forename: Björn
authors.initials: B
authors.lastname: Söderfeldt
authors.forename: Mats
authors.initials: M
authors.lastname: Kronström
mesh_terms: D000368:Aged; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003834:Denture Precision Attachment; D003827:Denture, Complete, Upper; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D015993:Life Tables; D008297:Male; D008437:Maxilla; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies