title: Ceramic-Veneered Zirconia Frameworks in Full-Arch Implant Rehabilitations: A 6-Month to 5-Year Retrospective Cohort Study.
abstract: OBJECTIVE
  This was a retrospective cohort study designed to evaluate the clinical performance of ceramic-veneered zirconia frameworks.
  
  
  METHODS
  Patients were recruited according to defined inclusion criteria. All patients were checked every 4 months from the time of definitive rehabilitation. At the end of 2013, all patients were rescheduled and rechecked for study purposes. The restorative procedures assessment was performed by previously established methods. The primary outcomes were the survival and success rates of the prosthesis. Descriptive statistics were used for the patient's demographics, implant distribution, and occurrence of complications. To study the survival and success of the prostheses, a Cox Regression analysis was used with a model constructed in a forward conditional stepwise mode. Predictive variables were included in the model, and adjusted survival curves were obtained for each outcome.
  
  
  RESULTS
  From 2008 to 2013, 75 patients were rehabilitated with 92 implant-supported, screw-retained, full-arch ceramic-veneered zirconia framework rehabilitations. The range of follow-up was between 6 months and 5 years. From the 92 full implant-supported screw-retained full-arch rehabilitations, Cox regression analysis indicated that within a 5-year time frame, the probability of framework fracture, major chipping, minor chipping, or any of the former combined to occur was 17.6%, 46.5%, 69.2%, and 90.5%, respectively.
  
  
  CONCLUSIONS
  Results suggest zirconia as a suitable material for framework structure in implant-supported, full-arch rehabilitations. However, it experiences a high incidence of technical complications, mainly due to ceramic chipping. Further clinical studies should aim to ascertain the effects of clinical features and manufacturing procedures on the survival rates of these prostheses.
authors.forename: João Manuel
authors.initials: JM
authors.lastname: Mendez Caramês
authors.forename: António Duarte
authors.initials: AD
authors.lastname: Sola Pereira da Mata
authors.forename: Duarte Nuno
authors.initials: DN
authors.lastname: da Silva Marques
authors.forename: Helena Cristina
authors.initials: HC
authors.lastname: de Oliveira Francisco
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002516:Ceramics / Q000737:chemistry / Q000627:therapeutic use*; D003764:Dental Materials / Q000627:therapeutic use*; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D015040:Zirconium / Q000627:therapeutic use*
chemical_list: D003764:Dental Materials; D015040:Zirconium; C028541:zirconium oxide