title: Comparison of implant versus tooth-supported zirconia-based single crowns in a split-mouth design: a 4-year clinical follow-up study.
abstract: OBJECTIVE
  This study aims to evaluate the 4-year clinical performance of tooth versus implant-supported single-unit zirconia crowns (LAVA™) placed on posterior region.
  
  
  METHODS
  Twenty-four patients (10 men and 14 women) who had received 48 single crowns (24 implant-supported and 24 tooth-supported) from January 2007 to December 2009, were included. California Dental Association (CDA) quality assessment system, plaque and gingival index scores were used to evaluate the performance of the crowns at baseline and at all follow-up examinations.
  
  
  RESULTS
  During the follow-up period, no fracture of zirconia coping has occurred. Major complication was chipping in three patients that required a new crown fabrication. Except for the failure ones, all crowns in both groups were rated as satisfactory at the follow-up examinations based on the CDA quality assessment criteria. There were no statistically significant differences between tooth and implant-supported crowns in terms of periodontal parameters.
  
  
  CONCLUSIONS
  The present 4-year follow-up clinical study demonstrates that single-unit tooth- and implant-supported zirconia crowns have similar prosthetic and periodontal outcomes.
  
  
  CONCLUSIONS
  Single-unit implant or tooth-supported zirconia crowns may be considered acceptable treatment modalities for restoration of either missing or compromised posterior teeth.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. barisguncu@hacettepe.edu.tr.
authors.forename: Mustafa Barış
authors.initials: MB
authors.lastname: Güncü
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Medipol University, İstanbul, Turkey.
authors.forename: Umut
authors.initials: U
authors.lastname: Cakan
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Guliz
authors.initials: G
authors.lastname: Aktas
authors.affiliation: Department of Periodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Güliz Nigar
authors.initials: GN
authors.lastname: Güncü
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Şenay
authors.initials: Ş
authors.lastname: Canay
mesh_terms: D000328:Adult; D003442:Crowns; D003774:Dental Plaque Index; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010512:Periodontal Index; D016896:Treatment Outcome; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide
keywords: All ceramic; Clinical; Dental implants; Follow-up study; Zirconia