Lithium disilicate glass ceramics with improved properties were prepared via a thermal treatment method by varying its composition. This study aims to investigate the influence of the concentration of Al2O3 additive oxides on the phase formation and mechanical properties of lithium disilicate glass ceramics prepared by conventional method. The Al2O3 concentration used are 3.0, 4.5, and 6.0 mol% for LCA1, LCA2, and LCA 3, respectively. As the content of Al2O3 increased the glass transition temperature (Tg), the crystallization temperature (Tc), phase formation, and mechanical properties of lithium disilicate glass ceramics varied considerably, demonstrating the substantial effect of Al2O3. After heat treatment at 600 °C and 800 °C for 1 h, the x-ray diffraction results showed that the major phase in all the glass-ceramic samples was Li2Si2O5 and the minor phases were CeO2, LiAlSi3O8, quartz, and Li2SiO3. For the lowest content of Al2O3, the highest flexural strength and Vickers hardness were obtained as 188.34 MPa and 776 HV, respectively. These results were attributed to the interlocking microstructure of rod-like Li2Si2O5 in the LCA1 sample.

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Owing to its excellent mechanical properties and aesthetic tooth-like appearance, lithium disilicate glass–ceramic is more attractive as a crown for dental restorations. In this study, lithium disilicate glass–ceramics were prepared from SiO2–Li2O–K2O–P2O5–CeO2 glass systems with various Al2O3 contents. The mixed glass was then heat-treated at 600 °C and 800 °C for 2 h to form glass–ceramic samples. Phase formation, microstructure, mechanical properties and bioactivity were investigated. The phase formation analysis confirmed the presence of Li2Si2O5 in all the samples. The glass–ceramic sample with an Al2O3 content of 1 wt% showed rod-like Li2Si2O5 crystals that could contribute to the delay in crack propagation and demonstrated the highest mechanical properties. Surface treatment with hydrofluoric acid followed by a silane-coupling agent provided the highest micro-shear bond strength for all ceramic conditions, with no significant difference between ceramic samples. The biocompatibility tests of the material showed that Al2O3-added lithium disilicate glass–ceramic sample was bioactive, thus activating protein production and stimulating the alkaline phosphatase (ALP) activity of osteoblast-like cells.

This study aims to investigate the influence of heat treatment temperatures on the mechanical properties and chemical solubility (CS) of lithium disilicate‐fluorcanasite glass‐ceramics and to develop new dental materials. The glasses and glass‐ceramics were prepared using CaF2‐SiO2‐CaO‐K2O‐Na2O‐Li2O‐Al2O3‐P2O5‐based glass system using a conventional melt quenching method followed by a two‐stage crystallization process. This two‐stage method involves two heating temperature steps: first at a constant temperature (TS1) of 600°C and second step at varying temperatures (TS2) of 650, 700, 750, and 800°C. The crystallization behavior, phase formation, microstructure, translucency characteristic, density, hardness, fracture strength, and CS were investigated. It was found that the lithium disilicate crystal acted as the main crystalline phase, and the crystalline phase of fluorcanasite occurred at the heat treatment temperatures of 750 and 800°C. In addition, it was found that density, hardness, fracture strength, and CS increased while the translucency values decreased with increasing heat treatment temperatures. Furthermore, the CS increased dramatically when the fluorcanasite phases occurred in the glass‐ceramic samples. The maximum density values, Vickers hardness, fracture toughness, and flexural strength are 2.56 g/cm3, 6.73 GPa, 3.38 MPa.m1/2, and 259 MPa, respectively. These results may offer a possibility to design a new material for dental applications based on lithium disilicate‐fluorcanasite glass‐ceramics.