title: Eleven-Year Follow-Up of a Prospective Study of Zirconia Implant Abutments Supporting Single All-Ceramic Crowns in Anterior and Premolar Regions.
abstract: BACKGROUND
  Clinical studies on zirconia abutments report very good survival rates and biological and technical results, but few have an observation period of more than 5 years.
  
  
  OBJECTIVE
  The aim of this study was to assess the long-term performance of customized zirconia implant abutments supporting all-ceramic crowns.
  
  
  METHODS
  Twenty-seven patients receiving 54 single implants were included (25 incisors, 14 canines, 15 premolars in both jaws). Yttria-stabilized zirconia abutments were screwed to the implants with a defined torque. All-ceramic crowns were adhesively cemented onto the abutments. The implants, abutments, and crowns were clinically and radiographically examined after 11 years of use. Modified United States Public Health Service (USPHS) criteria were used to assess technical outcomes: fracture of abutment/crown framework/veneering ceramic, loosening of abutment screw/crown, marginal adaptation, anatomical form, occlusal wear, and abutment fit. The biological parameters were pocket probing depth, plaque control record, bleeding on probing, papilla index, and gingival/mucosal recession at implants and neighboring natural teeth. The cumulative success rate of abutments and crowns was calculated by the Kaplan-Meier method. The results of the USPHS criteria were analyzed descriptively.
  
  
  RESULTS
  Sixteen patients with 31 zirconia abutments were examined at 11.3 (±0.9) years after implantation. No abutment or crown was lost. The cumulative success rate was 96.3% for abutments and 90.7% for crowns. Two abutment screws loosened, and three crowns exhibited minor chipping. There were no biological complications.
  
  
  CONCLUSIONS
  Customized zirconia single implant abutments exhibited excellent long-term outcomes in anterior and premolar regions.
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center for Dental Medicine, University of Zurich, Zurich, Switzerland.|Department of Oral Implantology and Prosthetic Dentistry, Academic Center for Dentistry Amsterdam, MOVE Research Institute, Amsterdam, The Netherlands.
authors.forename: Anja
authors.initials: A
authors.lastname: Zembic
authors.affiliation: Effretikon, Switzerland.|Clinic for Preventive Dentistry, Periodontology and Cariology, Center for Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Alexander Otto Hermann
authors.initials: AO
authors.lastname: Philipp
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center for Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Christoph Hans Franz
authors.initials: CH
authors.lastname: Hämmerle
authors.affiliation: Schellenberg, Liechtenstein.
authors.forename: Arnold
authors.initials: A
authors.lastname: Wohlwend
authors.affiliation: Clinic of Fixed Prosthodontics and Biomaterials, School of Dental Medicine, University of Geneva, Geneva, Switzerland.
authors.forename: Irena
authors.initials: I
authors.lastname: Sailer
mesh_terms: D001641:Bicuspid / Q000601:surgery; D002516:Ceramics; D003442:Crowns; D003481:Cuspid / Q000601:surgery; D000044:Dental Abutments; D059605:Dental Implant-Abutment Design / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000601:surgery; D008297:Male; D011446:Prospective Studies; D013997:Time Factors; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide
keywords: ceramics; dental implants; implant abutments; outcome assessment; single-tooth; survival rate; zirconia