title: Crestal bone loss and periimplant inflammatory parameters around zirconia implants: A systematic review.
abstract: BACKGROUND
  Zirconia implants have been used for oral rehabilitation; however, evidence of their ability to maintain crestal bone and periimplant soft tissue health is not clear.
  
  
  OBJECTIVE
  The purpose of this systematic review was to evaluate crestal bone loss (CBL) around zirconia dental implants and clinical periimplant inflammatory parameters.
  
  
  METHODS
  The focus question addressed was, "Do zirconia implants maintain crestal bone levels and periimplant soft tissue health?" Databases were searched for articles from 1977 through September 2014 with different combinations of the following MeSH terms: "dental implants," "zirconium," "alveolar bone loss," "periodontal attachment loss," "periodontal pocket," "periodontal index." Letters to the editor, case reports, commentaries, review articles, and articles published in languages other than English were excluded.
  
  
  RESULTS
  Thirteen clinical studies were included. In 8 of the studies, the CBL around zirconia implants was comparable between baseline and follow-up. In the other 5 studies, the CBL around zirconia implants was significantly higher at follow-up. Among the studies that used titanium implants as controls, 2 studies showed significantly higher CBL around zirconia implants, and in 1 study, the CBL around zirconia and titanium implants was comparable. The reported implant survival rates for zirconia implants ranged between 67.6% and 100%. Eleven studies selectively reported the periimplant inflammatory parameters.
  
  
  CONCLUSIONS
  Because of the variations in study design and methodology, it was difficult to reach a consensus regarding the efficacy of zirconia implants in maintaining crestal bone levels and periimplant soft tissue health.
authors.affiliation: Assistant Professor, Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia. Electronic address: fahimvohra@yahoo.com.
authors.forename: Fahim
authors.initials: F
authors.lastname: Vohra
authors.affiliation: Associate Professor and Chair, Dental Materials Research, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Abdul Aziz
authors.initials: AA
authors.lastname: Al-Kheraif
authors.affiliation: Senior Lecturer and Head, Centre for Restorative Dentistry Studies, Faculty of Dentistry, University of Technology (MARA), Shah Alam, Malaysia.
authors.forename: Siti Mariam
authors.initials: SM
authors.lastname: Ab Ghani
authors.affiliation: Dean, Faculty of Dentistry, Department of Restorative Dentistry, University of Technology (MARA), Shah Alam, Malaysia.
authors.forename: Mohamed Ibrahim
authors.initials: MI
authors.lastname: Abu Hassan
authors.affiliation: Assistant Professor, Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Talal
authors.initials: T
authors.lastname: Alnassar
authors.affiliation: Research Associate, Eastman Institute for Oral Health, Division of General Dentistry, University of Rochester, Rochester, NY.
authors.forename: Fawad
authors.initials: F
authors.lastname: Javed
mesh_terms: D016301:Alveolar Bone Loss; D015921:Dental Implants; D003764:Dental Materials; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D010512:Periodontal Index; D010514:Periodontal Pocket; D015040:Zirconium
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D015040:Zirconium; C028541:zirconium oxide