title: Influence of prosthesis type and retention mechanism on complications with fixed implant-supported prostheses: a systematic review applying multivariate analyses.
abstract: OBJECTIVE
  To identify the influence of fixed prosthesis type on biologic and technical complication rates in the context of screw versus cement retention. Furthermore, a multivariate analysis was conducted to determine which factors, when considered together, influence the complication and failure rates of fixed implant-supported prostheses.
  
  
  METHODS
  Electronic searches of MEDLINE (PubMed), EMBASE, and the Cochrane Library were conducted. Selected inclusion and exclusion criteria were used to limit the search. Data were analyzed statistically with simple and multivariate random-effects Poisson regressions.
  
  
  RESULTS
  Seventy-three articles qualified for inclusion in the study. Screw-retained prostheses showed a tendency toward and significantly more technical complications than cemented prostheses with single crowns and fixed partial prostheses, respectively. Resin chipping and ceramic veneer chipping had high mean event rates, at 10.04 and 8.95 per 100 years, respectively, for full-arch screwed prostheses. For "all fixed prostheses" (prosthesis type not reported or not known), significantly fewer biologic and technical complications were seen with screw retention. Multivariate analysis revealed a significantly greater incidence of technical complications with cemented prostheses. Full-arch prostheses, cantilevered prostheses, and "all fixed prostheses" had significantly higher complication rates than single crowns. A significantly greater incidence of technical and biologic complications was seen with cemented prostheses.
  
  
  CONCLUSIONS
  Screw-retained fixed partial prostheses demonstrated a significantly higher rate of technical complications and screw-retained full-arch prostheses demonstrated a notably high rate of veneer chipping. When "all fixed prostheses" were considered, significantly higher rates of technical and biologic complications were seen for cement-retained prostheses. Multivariate Poisson regression analysis failed to show a significant difference between screw- and cement-retained prostheses with respect to the incidence of failure but demonstrated a higher rate of technical and biologic complications for cement-retained prostheses. The incidence of technical complications was more dependent upon prosthesis and retention type than prosthesis or abutment material.
authors.forename: Christopher
authors.initials: C
authors.lastname: Millen
authors.forename: Urs
authors.initials: U
authors.lastname: Brägger
authors.forename: Julia-Gabriela
authors.initials: JG
authors.lastname: Wittneben
mesh_terms: D001863:Bone Screws / Q000592:standards; D002484:Cementation / Q000379:methods; D003738:Dental Cements / Q000592:standards; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported / Q000009:adverse effects / Q000379:methods / Q000592:standards*; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D006801:Humans; D015999:Multivariate Analysis; D011183:Postoperative Complications; D060489:Prosthesis Retention; D012044:Regression Analysis
chemical_list: D003738:Dental Cements