title: Biaxial flexural strength of Turkom-Cera core compared to two other all-ceramic systems.
abstract: Advances in all-ceramic systems have established predictable means of providing metal-free aesthetic and biocompatible materials. These materials must have sufficient strength to be a practical treatment alternative for the fabrication of crowns and fixed partial dentures.
  
  
  OBJECTIVE
  The aim of this study was to compare the biaxial flexural strength of three core ceramic materials.
  
  
  METHODS
  Three groups of 10 disc-shaped specimens (16 mm diameter x 1.2 mm thickness - in accordance with ISO-6872, 1995) were made from the following ceramic materials: Turkom-Cera Fused Alumina [(Turkom-Ceramic (M) Sdn Bhd, Puchong, Selangor, Malaysia)], In-Ceram (Vita Zahnfabrik, Bad Säckingen, Baden-Württemberg, Germany) and Vitadur-N (Vita Zahnfabrik, Bad Säckingen, Baden-Württemberg, Germany), which were sintered according to the manufacturer's recommendations. The specimens were subjected to biaxial flexural strength test in an universal testing machine at a crosshead speed of 0.5 mm/min. The definitive fracture load was recorded for each specimen and the biaxial flexural strength was calculated from an equation in accordance with ISO-6872.
  
  
  RESULTS
  The mean biaxial flexural strength values were: Turkom-Cera: 506.8 ± 87.01 MPa, In-Ceram: 347.4 ± 28.83 MPa and Vitadur-N: 128.7 ± 12.72 MPa. The results were analyzed by the Levene's test and Dunnett's T3 post-hoc test (SPSS software V11.5.0 for Windows, SPSS, Chicago, IL, USA ) at a preset significance level of 5% because of unequal group variances (P<0.001). There was statistically significant difference between the three core ceramics (P<0.05). Turkom-Cera showed the highest biaxial flexural strength, followed by In-Ceram and Vitadur-N.
  
  
  CONCLUSIONS
  Turkom-Cera core had significantly higher flexural strength than In-Ceram and Vitadur-N ceramic core materials.
authors.affiliation: Department of Conservative Dentistry, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia. makramani@yahoo.com
authors.forename: Bandar Mohammed Abdullah
authors.initials: BM
authors.lastname: Al-Makramani
authors.forename: Abdul Aziz Abdul
authors.initials: AA
authors.lastname: Razak
authors.forename: Mohamed Ibrahim
authors.initials: MI
authors.lastname: Abu-Hassan
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D008422:Materials Testing; D018583:Pliability; D013314:Stress, Mechanical
chemical_list: C105314:AllCeram; D003764:Dental Materials; C483026:In-Ceram Alumina; D003776:Dental Porcelain; C058236:Vitadur N; D000537:Aluminum Oxide