title: Translucency and biaxial flexural strength of four ceramic core materials.
abstract: OBJECTIVE
  To assess the relative translucencies and flexural strengths of four dental restorative ceramic core materials.
  
  
  METHODS
  Eight disk specimens (14 mm in diameterx 0.5+/-0.05 mm in thickness) were prepared for each group of four ceramic core materials (IPS Empress 2 dentin, VITA In-Ceram Alumina, VITA In-Ceram Zirconia, Cercon Base Zirconia), according to the manufacturers' instructions. A color meter was used to measure the relative translucencies of the specimens. The biaxial flexure test (ISO 6872) was then used to measure their flexural strengths. Data for relative translucency (0.0-1.0), fracture load (N) and biaxial flexural strength (MPa) were analyzed by one-way ANOVA, followed by Tukey's multiple comparison test for significant findings (alpha = 0.05).
  
  
  RESULTS
  For relative translucency: IPS Empress 2 (0.78+/-0.03), VITA In-Ceram Alumina (0.94+/-0.01), VITA In-Ceram Zirconia (1.00+/-0.01), Cercon Base Zirconia (1.00+/-0.01), P<0.0001. For biaxial flexural strength: IPS Empress 2 (355.1+/-25.7), VITA In-Ceram Alumina (514.0+/-49.5), VITA In-Ceram Zirconia (592.4+/-84.7), Cercon Base Zirconia (910.5+/-95.3), P<0.0001.
  
  
  CONCLUSIONS
  IPS Empress 2 and VITA In-Ceram Alumina were significantly more translucent than the two opaque zirconia-containing core materials. IPS Empress 2 was significantly weaker, and Cercon Base Zirconia was significantly stronger, than the other two ceramic core materials.
authors.affiliation: Dental Research Institute, College of Stomatology, Nanjing Medical University, Nanjing, PR China.
authors.forename: Ya-Ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Smales
authors.forename: Kevin H-K
authors.initials: KH
authors.lastname: Yip
authors.forename: Wei-Jia
authors.initials: WJ
authors.lastname: Sung
mesh_terms: D003442:Crowns; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D008422:Materials Testing; D055620:Optical Phenomena; D018583:Pliability
chemical_list: D003776:Dental Porcelain