title: Clinical outcomes of zirconia-based implant- and tooth-supported single crowns.
abstract: OBJECTIVE
  Zirconia-based restorations have been increasingly used on implant and teeth abutments, but the evidence about clinical outcomes of these restorations is limited. The aim of this study was to assess up to 7-year clinical outcomes of implant- and tooth-supported zirconia-based single crowns.
  
  
  METHODS
  In this retrospective study, 261 patients with 556 single crowns supported by either teeth (324) or implants (232) were examined during 3- to 7-year follow-up (mean observation of 60.70 months for tooth and 59.20 months for implant-supported crowns). California Dental Association (CDA) quality evaluation system was used to evaluate the restorations. Soft tissue status was assessed using plaque and gingival index scores, bleeding on probing, and pocket depth. Patient and professional satisfaction were evaluated by visual analog scale (VAS).
  
  
  RESULTS
  The 5-year Kaplan-Meier survival probability was 98.3 and 97.3 for implant- and tooth-supported crowns, respectively. In regard to CDA rating, most of the crowns were ranked as either excellent or acceptable (99.5 %). The recorded failures were replacement of the crown due to porcelain chipping (3), implant failure (1), and teeth extraction (5). Soft tissue parameters were not affected by the restorations compare to control teeth. The VAS was high for both patients and clinicians.
  
  
  CONCLUSIONS
  Zirconia-based single crowns on both tooth and implant abutments showed promising clinical performance in this up to 7-year follow-up.
  
  
  CONCLUSIONS
  The zirconia-based single crowns can be used clinically for tooth- and implant-supported restorations.
authors.affiliation: Dental Materials Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Farahnaz
authors.initials: F
authors.lastname: Nejatidanesh
authors.affiliation: Department of Prosthodontics, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Hedayat
authors.initials: H
authors.lastname: Moradpoor
authors.affiliation: Torabinejad Dental Research Center, School of Dentistry, Isfahan University of Medical Sciences, #400-Sheikhsadoogh Shomali St. Sheikhsadoogh Cross Road, Isfahan, 81648-13315, Iran. Savabi@hotmail.com.
authors.forename: Omid
authors.initials: O
authors.lastname: Savabi
mesh_terms: D000368:Aged; D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D012189:Retrospective Studies; D016896:Treatment Outcome; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide
keywords: Computer-aided design; Crowns; Dental restoration failures; Survival analysis; Treatment outcome; Zirconium oxide