Mechanical properties of zirconia reinforced lithium silicate glass-ceramic

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• 作者：Shaymaa E. Elsaka^a ; ^{shaymanaghy@mans.edu.eg" class="auth_mail" title="E-mail the corresponding author} ; Amr M. Elnaghy^b
• 关键词：Brittleness index ; Lithium disilicate ; Mechanical properties ; Weibull analysis ; Zirconia reinforced lithium silicate
• 刊名：Dental Materials
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：32
• 期：7
• 页码：908-914
• 全文大小：1221 K

文摘

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 ± 0.17 MPa m^0.5), flexural strength (443.63 ± 38.90 MPa), elastic modulus (70.44 ± 1.97 GPa), and hardness (6.53 ± 0.49 GPa) than IC (P < 0.001). On the other hand, VS glass-ceramic revealed significantly a higher brittleness index (2.84 ± 0.26 μm^−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.