title: Short-term results of IPS-Empress full-porcelain crowns.
abstract: OBJECTIVE
  A leucite-reinforced, glass-ceramic material was recently introduced for clinical use. In this clinical trial, IPS-Empress material was tested in the form of full-porcelain crowns.
  
  
  METHODS
  Thirty-four patients were restored with 78 full-porcelain crowns. After etching the crowns with hydrofluoric acid, they were silanized and luted using dentin bonding agents and resin composite cement, which was primarily a dual-cured type. The 41 anterior and 37 posterior crowns were evaluated clinically with a mirror and probe, radiographically, and using clinical photographs, according to the modified United States Public Health Service criteria. Restorations having neither charlie nor delta criteria were defined as successful, and their survival rate was calculated according to Kaplan-Meier analysis.
  
  
  RESULTS
  The mean observation period for the 78 restorations was 19.7 +/- 8.5 months. Seventy-four crowns were defined as successful. Four restorations failed because of fractures. Three of the four failures occurred in the first 2 months after cementation. The survival rate was estimated to be 95% successful after 2 years in service. Eighty percent of the crowns demonstrated an excellent esthetic result.
  
  
  CONCLUSIONS
  The initial clinical results of this esthetic full-porcelain crown system are encouraging. However, because of fatigue phenomena for all ceramic materials, a longer observation period is needed to provide a definitive prognosis about the long-term clinical behavior.
authors.affiliation: Department of Fixed and Removable Prosthodontics and Dental Materials, p3hool of Dental Medicine, Zurich University, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Lehner
authors.forename: S
authors.initials: S
authors.lastname: Studer
authors.forename: U
authors.initials: U
authors.lastname: Brodbeck
authors.forename: P
authors.initials: P
authors.lastname: Schärer
mesh_terms: D000538:Aluminum Silicates; D002484:Cementation / Q000379:methods; D003442:Crowns / Q000706:statistics & numerical data; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D016019:Survival Analysis; D013997:Time Factors; D019231:Tooth Preparation, Prosthodontic / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000538:Aluminum Silicates; C075815:IPS-Empress ceramic; D003776:Dental Porcelain