Mechanical properties of zirconia reinforced lithium silicate glass ceramic.
OBJECTIVE The aim of this study was to assess the mechanical properties of recently introduced zirconia reinforced lithium silicate glass ceramic. METHODS 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. RESULTS 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+ 0.26mm( 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. SIGNIFICANCE The VS zirconia reinforced lithium silicate glass ceramic revealed higher mechanical properties compared with IC lithium disilicate glass ceramic.
Dental materials official publication of the Academy of Dental Materials