Additively manufactured lithium disilicate glass-ceramics for dental applications: Role of heat treatment on densification, microstructural evolution, and strengthening-toughening

In this study, lithium disilicate glass-ceramic green bodies were prepared using digital light processing technology, utilizing a precursor slurry with good rheological and photocuring properties. The green bodies underwent debinding, nucleation, and crystallization, followed by densification at the glass melting temperature. We investigated the effects of crystallization time and densification time on the microstructure, mechanical properties, translucency, chemical solubility, and cytotoxicity of the glass-ceramics. The results showed that precise control of densification balanced internal defects and molding quality. Increased crystallization and densification times significantly improved crystallinity, density, flexural strength, and translucency. However, fracture toughness was only enhanced by crystallization time, with intergranular being the fracture main mode. The preferred samples exhibited strength, toughness, and translucency parameters of 284.5   MPa, 2.3   MPa·m 1/2 , and 12.3, respectively. Additionally, these samples showed good resistance to cold and hot aging, chemical solubility, and cytocompatibility, meeting the clinical requirements for dental restorations.