title: Clinical wear of overdenture ball attachments after 1, 3 and 8 years.
abstract: OBJECTIVE
  Implant-supported overdentures have become the treatment of choice in restoring complete edentulism, but the types of attachment to assure durable retention are a subject of debate. Ball attachments were reported as a simple treatment, but wear of components was responsible for a decrease in retention. The aim of this retrospective study was to measure the wear of the ball abutment or patrix after three different periods of clinical wear.
  
  
  METHODS
  Sixty-nine specimens of three groups of patrix that were in use for a mean of 12.3 months (group A), 39 months (group B) and 95.6 months (group C) were retrieved from 35 patients and measured on a coordinate measuring machine equipped with a touch trigger probe. Ten unused ball abutments were added as a control (group D). The patrix diameters and any deviation from circularity in different axes were measured.
  
  
  RESULTS
  The diameters of groups A, B and C were significantly different from that of group D (control). No statistically significant differences were found between diameter and circularity variations between groups B and C. The maximal amount of diameter reduction was limited to approximately 30 μm, and 90% of diameter loss at the equator due to wear was reached in group B.
  
  
  CONCLUSIONS
  One, 3 and 8 years of clinical wear reduced significantly the diameters of the ball abutments tested, and the maximal amount of wear was reached after 3 years of clinical use.
authors: UFR of Odontology, Paris 7-Denis Diderot University, Paris, France.
authors: Olivier
authors: O
authors: Fromentin
authors: Claire
authors: C
authors: Lassauzay
authors: Samer Abi
authors: SA
authors: Nader
authors: Jocelyne
authors: J
authors: Feine
authors: Rubens F
authors: RF
authors: de Albuquerque
mesh_terms: D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D019554:Dental Restoration Wear; D003781:Denture Retention / Q000295:instrumentation*; D003828:Denture, Overlay; D005500:Follow-Up Studies; D006801:Humans; D012189:Retrospective Studies; D013499:Surface Properties
chemical_list: D015921:Dental Implants