title: A meta-analysis of retention systems for implant-supported prostheses in partially edentulous jaws.
abstract: BACKGROUND
  Choosing an appropriate retention system for patients with partial edentulism and dental implants is impeded by a paucity of evidence. The available evidence is extrapolated from either completely edentulous or mixed study populations.
  
  
  OBJECTIVE
  The purpose of this systematic review was to assess the effects of different retention systems used for implant-supported prostheses in patients with partially edentulous jaws by measuring the rates of failure, survival, and event-free situations.
  
  
  METHODS
  An electronic database search supplemented by a manual search was conducted to identify the best, good, and fair quality studies reporting at least 10 participants with a 1-year follow-up (PROSPERO-CRD 42015024649). Summary estimates of the survival, failure, and event-free proportions were obtained using a random effects model with a 95% confidence interval.
  
  
  RESULTS
  Among the 896 citations from 3875 titles identified by the search, 104 studies reporting over 5317 participants with 9568 reconstructions and a total exposure time of 46553.18 years were included in the analysis. Screw-retained single crowns showed twofold minor complication even rates (8.5%; 95% confidence interval [CI]: 5.5-12.9) compared with cement-retained single crowns (4.2%. 95% CI; 3.2-5.4). None of the retention systems were more advantageous than the others in relation to failure and event-free outcomes. However, the summary of the findings suggests that cement-retained single crowns, splinted crowns, and cantilever-fixed partial dentures performed better (with fewer events) than screw-retained restorations in the long term.
  
  
  CONCLUSIONS
  Results suggest that cement retention may be an appropriate system for implant-supported restorations in partial edentulism. However, high-quality prospective studies and cost evaluation are recommended to confirm the evidence.
authors.affiliation: Predoctoral student, Faculty of Dentistry, McGill University, Montreal, Quebec, Canada.
authors.forename: Murali
authors.initials: M
authors.lastname: Ramamoorthi
authors.affiliation: Predoctoral student, Faculty of Dentistry, McGill University, Montreal, Quebec, Canada.
authors.forename: Aparna
authors.initials: A
authors.lastname: Narvekar
authors.affiliation: Associate Professor, Faculty of Dentistry, McGill University, Montreal, Quebec, Canada. Electronic address: shahrokh.esfandiari@mcgill.ca.
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Esfandiari
mesh_terms: D003758:Dental Implantation, Endosseous / Q000379:methods; D017268:Dental Prosthesis Retention / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported / Q000379:methods*; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000601:surgery*