title: Flexural resistance of Cerec CAD/CAM system ceramic blocks. Part 2: Outsourcing materials.
abstract: OBJECTIVE
  To test different Cerec CAD/CAM system ceramic blocks, comparing mean flexural strength (sigma), Weibull modulus (m), and Weibull characteristic strength (sigma0) in an ISO standardized set-up.
  
  
  METHODS
  Following the recent ISO Standard (ISO 6872:2008), 11 types of ceramic blocks were tested: IPS e.max CAD MO, IPS e.max CAD LT and IPS e.max CAD HT (lithium disilicate glass-ceramic); In-Ceram SPINELL, In-Ceram Alumina and In-Ceram Zirconia (glass-infiltrated materials); inCoris AL and In-Ceram AL (densely sintered alumina); In-Ceram YZ, IPS e.max Zir-CAD and inCoris ZI (densely sintered zirconia). Specimens were cut out from ceramic blocks, finished, crystallized/infiltrated/sintered, polished, and tested in a three-point bending test apparatus. Flexural strength, Weibull characteristic strength, and Weibull modulus were obtained.
  
  
  RESULTS
  A statistically significant difference was found (P < 0.001) among lithium disilicate glass-ceramic (sigma = 272.6 +/- 376.8 MPa, m = 6.2 +/- 11.3, sigma0 = 294.0 +/- 394.1 MPa) and densely sintered alumina (sigma = 441.8 +/- 541.6 MPa, m = 11.9 +/- 19.0, sigma0 = 454.2 +/- 565.2 MPa). No statistically significant difference was found (P = 0.254) in glass infiltrated materials (sigma = 376.9 +/- 405.5 MPa, m = 7.5 +/- 11.5, sigma0 = 393.7 +/- 427.0 MPa). No statistically significant difference was found (P = 0.160) in densely sintered zirconia (sigma = 1,060.8 +/- 1,227.8 MPa, m = 5.8 +/- 7.4, sigma0 = 1,002.4 +/- 1,171.0 MPa). Not all the materials tested fulfilled the requirements for the clinical indications recommended by the manufacturer.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sedda
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vichi
authors.forename: Francesco
authors.initials: F
authors.lastname: Del Siena
authors.forename: Chris
authors.initials: C
authors.lastname: Louca
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D017076:Computer-Aided Design; D003776:Dental Porcelain / Q000737:chemistry*; D055119:Elastic Modulus; D006801:Humans; D008277:Magnesium Oxide / Q000737:chemistry; D008422:Materials Testing; D018583:Pliability; D013314:Stress, Mechanical; D013499:Surface Properties; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: C520133:IPS e.max CAD LT; C483026:In-Ceram Alumina; C485633:In-Ceram Zirconia; C493120:lithia disilicate; C111130:spinell; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D008277:Magnesium Oxide; D015019:Yttrium; C023506:Glass ceramics; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide