title: Mechanical properties of zirconia reinforced lithium silicate glass-ceramic.
abstract: The aim of this study was to assess the mechanical properties of recently introduced zirconia reinforced lithium silicate glass-ceramic.
  
  
  
  Two types of CAD/CAM glass-ceramics (Vita Suprinity (VS); zirconia reinforced lithium silicate and IPS e.max CAD (IC); lithium disilicate) were used. Fracture toughness, flexural strength, elastic modulus, hardness, brittleness index, and microstructures were evaluated. Data were analyzed using independent t tests. Weibull analysis of flexural strength data was also performed.
  
  
  
  VS had significantly higher fracture toughness (2.31±0.17MPam(0.5)), flexural strength (443.63±38.90MPa), elastic modulus (70.44±1.97GPa), and hardness (6.53±0.49GPa) than IC (P<0.001). On the other hand, VS glass-ceramic revealed significantly a higher brittleness index (2.84±0.26μm(-1/2)) (lower machinability) than IC glass-ceramic (P<0.05). VS demonstrated a homogeneous fine crystalline structure while, IC revealed a structure with needle-shaped fine-grained crystals embedded in a glassy matrix. The VS glass-ceramic revealed a lower probability of failure and a higher strength than IC glass-ceramic according to Weibull analysis.
  
  
  
  The VS zirconia reinforced lithium silicate glass-ceramic revealed higher mechanical properties compared with IC lithium disilicate glass-ceramic.
authors.affiliation: Department of Dental Biomaterials, Faculty of Dentistry, Mansoura University, Mansoura, Egypt. Electronic address: shaymanaghy@mans.edu.eg.
authors.forename: Shaymaa E
authors.initials: SE
authors.lastname: Elsaka
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
authors.forename: Amr M
authors.initials: AM
authors.lastname: Elnaghy
mesh_terms: D002516:Ceramics; D003776:Dental Porcelain; D008094:Lithium; D008422:Materials Testing; D017640:Silicates; D013499:Surface Properties; D015040:Zirconium
chemical_list: D017640:Silicates; D003776:Dental Porcelain; D008094:Lithium; D015040:Zirconium; C028541:zirconium oxide
keywords: Brittleness index; Lithium disilicate; Mechanical properties; Weibull analysis; Zirconia reinforced lithium silicate