title: Implant supported overdentures--the Copenhagen experience.
abstract: OBJECTIVE
  To evaluate the functional and biological effect of implant-supported overdenture treatment in the lower jaw.
  
  
  METHODS
  Thirty-two patients were consecutively treated with Astra Tech implants in the lower jaw for retaining overdentures. All implants had a diameter of 3.5 mm and all but two of the implants were longer than 10 mm. For the implant supported overdentures two methods of attachment were used, a bar or a ball.
  
  
  RESULTS
  One of 69 fixtures was lost during the 4-5 year observation period. The mean bone loss for all fixtures was less than 0.2 mm per year. Complications included 15 fractures of the ball attachment and 26 episodes of looseness of the matrices holding the screw in place. Patient satisfaction with the treatment of the lower jaw was high although 7 patients found that control of the upper denture was poor following treatment.
  
  
  CONCLUSIONS
  When the bone quality and quantity is sufficient, two implants can support an overdenture in the lower jaw, providing prosthesis which functions well.
authors.affiliation: Department of Prosthetic Dentistry, University of Copenhagen, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Gotfredsen
mesh_terms: D000368:Aged; D003718:Denmark; D003774:Dental Plaque Index; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003834:Denture Precision Attachment; D003781:Denture Retention / Q000295:instrumentation*; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible; D008875:Middle Aged; D016348:Osseointegration; D017060:Patient Satisfaction; D010512:Periodontal Index; D016896:Treatment Outcome