title: Two-year clinical evaluation of lithia-disilicate-based all-ceramic crowns and fixed partial dentures.
abstract: OBJECTIVE
  The aim of this study was to evaluate the clinical performance of crowns and fixed partial dentures (FPDs) made with the Empress 2 system over a 2-year period.
  
  
  METHODS
  Twenty anterior or posterior all-ceramic (Empress 2) crowns and 20 anterior or posterior, three-unit fixed partial dentures were fabricated for 15 patients. Evaluations of the restorations were performed at baseline and once a year during the 2-year follow-up period. U.S. Public Health Service criteria were used to examine the marginal adaptation, color match, secondary caries and visible fractures in the restorations. Survival rate of the restorations were determined using Kaplan-Meier statistical analysis.
  
  
  RESULTS
  U.S. Public Health Service criteria showed 100% Alpha scores concerning recurrent caries for both crowns and FPDs. No crown fractures were observed during the 2-year follow-up, however, 10 (50%) catastrophic failures of FPDs occurred. Five (25%) failures occurred within the 1-year clinical period and the others (25%) within the second year.
  
  
  CONCLUSIONS
  Single unit Empress 2 all-ceramic crowns exhibited a satisfactory clinical performance over 2-year period. Furthermore, the high fracture rate of Empress 2 FPDs limits the usage of Empress 2 for the fabrication of all-ceramic FPD.
authors.affiliation: Department of Restorative Dentistry, Division of Dental Biomaterials, Indiana University, School of Dentistry, 1121 W. Michigan Street, Indianapolis, IN 46202, United States. btaskona@iupui.edu
authors.forename: Burak
authors.initials: B
authors.lastname: Taskonak
authors.forename: Atilla
authors.initials: A
authors.lastname: Sertgöz
mesh_terms: D000328:Adult; D002516:Ceramics / Q000737:chemistry; D003116:Color; D003442:Crowns; D003731:Dental Caries / Q000145:classification; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003807:Dentin Sensitivity / Q000145:classification; D003779:Denture Design; D003830:Denture, Partial, Fixed; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D018020:Lithium Compounds / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D017640:Silicates / Q000737:chemistry; D013499:Surface Properties; D016019:Survival Analysis
chemical_list: C118557:Empress 2; D018020:Lithium Compounds; D017640:Silicates; D003776:Dental Porcelain