title: A systematic review of the clinical survival of zirconia implants.
abstract: OBJECTIVE
  The aim of this review was to evaluate the clinical success and survival rates of zirconia ceramic implants after at least 1 year of function and to assess if there is sufficient evidence to justify using them as alternatives to titanium implants.
  
  
  METHODS
  An electronic search in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Clinical Trials (CENTRAL) databases was performed in April 2015 by two independent examiners to retrieve clinical studies focusing on the survival rate of zirconia implants after at least 1 year of function. Implant survival was estimated using the overall proportion reported in the studies with a Clopper-Pearson 95 % confidence interval (random effect model with a Der-Simonian Laird estimate).
  
  
  RESULTS
  Fourteen articles were selected out of the 1519 titles initially screened. The overall survival rate of zirconia one- and two-piece implants was calculated at 92 % (95 % CI 87-95) after 1 year of function. The survival of implants at 1 year for the selected studies revealed considerable heterogeneity.
  
  
  CONCLUSIONS
  In spite of the unavailability of sufficient long-term evidence to justify using zirconia oral implants, zirconia ceramics could potentially be the alternative to titanium for a non-metallic implant solution. However, further clinical studies are required to establish long-term results, and to determine the risk of technical and biological complications. Additional randomized controlled clinical trials examining two-piece zirconia implant systems are also required to assess their survival and success rates in comparison with titanium as well as one-piece zirconia implants.
  
  
  CONCLUSIONS
  Zirconia implants provide a potential alternative to titanium ones. However, clinicians must be aware of the lack of knowledge regarding long-term outcomes and specific reasons for failure.
authors.affiliation: School of Dental Medicine, Division of Periodontology, University of Geneva, Rue Barthelemy-Menn 19, CH-1205, Geneva, Switzerland. dr.dhashim@gmail.com.
authors.forename: Dena
authors.initials: D
authors.lastname: Hashim
authors.affiliation: School of Dental Medicine, Division of Periodontology, University of Geneva, Rue Barthelemy-Menn 19, CH-1205, Geneva, Switzerland.
authors.forename: Norbert
authors.initials: N
authors.lastname: Cionca
authors.affiliation: University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, CH-1205, Genève, Switzerland.
authors.forename: Delphine S
authors.initials: DS
authors.lastname: Courvoisier
authors.affiliation: School of Dental Medicine, Division of Periodontology, University of Geneva, Rue Barthelemy-Menn 19, CH-1205, Geneva, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mombelli
mesh_terms: D002516:Ceramics / Q000737:chemistry; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D014025:Titanium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide
keywords: Dental implants; Survival; Systematic review; Zirconia