title: Systematic review of prosthetic maintenance requirements for implant-supported overdentures.
abstract: OBJECTIVE
  To evaluate prosthetic maintenance requirements for implant-retained/supported overdentures via a review of the literature.
  
  
  METHODS
  Using the combined search terms "implant and overdenture," "implant-supported overdenture," "implant-retained overdenture," and "implant-anchored overdenture," along with specific inclusion and exclusion criteria, eligible articles between 1997 and 2008 (up to April 1) were retrieved from PubMed, EMBASE, OVID, the Cochrane Library databases, and seven journals by hand-searching. The initial search yielded 3,120 titles, and 287 articles were assigned to full-text analysis. Upon classification of the prosthetic complications with regard to the jaws treated and the attachment systems used, within- and between-group comparative frequency analyses were undertaken with the Kruskal-Wallis test or the Mann-Whitney U test at P < .05.
  
  
  RESULTS
  A total of 49 articles were included. Within- and between-group evaluations with regard to jaw treated as well as the attachment systems used showed that the frequency of complications did not change over time (P > .05). The differences detected were more matrix replacements after 5 years in the maxilla and mandible and more matrix replacements and patrix fractures after the first year in the mandible (P < .05). Among the attachment systems, a dislodged, worn, or loose matrix or its respective housing was more common in the ball-attachment group after the first year (P < .05). Prosthetic complications for all types of attachments were comparable (P > .05), except for the differences in peri-implant or interabutment mucosal enlargement rates after 1 year.
  
  
  CONCLUSIONS
  Prosthetic maintenance requirements for overdentures on both jaws seem to be comparable. The impact of attachment system on the prosthetic outcome is negligible.
authors.affiliation: CosmORAL Oral and Dental Health Polyclinics, Ankara, Turkey. mcehreli@hotmail.com
authors.forename: Murat Cavit
authors.initials: MC
authors.lastname: Cehreli
authors.forename: Durdu
authors.initials: D
authors.lastname: Karasoy
authors.forename: Ali Murat
authors.initials: AM
authors.lastname: Kokat
authors.forename: Kiyanc
authors.initials: K
authors.lastname: Akca
authors.forename: Steven E
authors.initials: SE
authors.lastname: Eckert
mesh_terms: D016734:Dental Clasps; D019094:Dental Prosthesis, Implant-Supported; D003834:Denture Precision Attachment; D003823:Denture Rebasing; D003780:Denture Repair; D003781:Denture Retention / Q000295:instrumentation; D003828:Denture, Overlay; D006801:Humans; D008283:Maintenance; D018709:Statistics, Nonparametric