Sintering and mechanical properties of lithium disilicate glass-ceramics prepared by sol-gel method

•Li2Si2O5 glass-ceramics powders with Li2Si2O5 as main crystalline phase were successfully fabricated by the sol-gel method.•The highest flexural strength of pressureless sintered Li2Si2O5 glass-ceramics was 137.1 MPa, with an interlocking microstructure.•The highest flexural strength of hot-pressed Li2Si2O5 glass-ceramics was 277 MPa, almost twice that of pressureless sintered samples. The aim of this study was to investigate the sintering and mechanical properties of lithium disilicate (Li2Si2O5) glass-ceramics prepared by sol-gel method. The results showed that Li2Si2O5 phase started to crystallize in the gel-derived powders around 500 °C. The glass-ceramics powders with a main phase of Li2Si2O5 were obtained after a calcination at 600 °C. Microstructure and flexural strength of pressureless sintered and hot-pressed glass-ceramics were further evaluated, respectively. The Li2Si2O5 glass-ceramic after sintering at 900 °C exhibited the highest flexural strength of 137.1 MPa with an interlocked microstructure. While, the hot-pressed samples could achieve higher densification and much higher flexural strength compared with the pressureless sintered samples, and a flexural strength of 277.0 MPa was obtained after sintering at 950 °C under a pressure of 16 MPa. The results suggest that Li2Si2O5 glass-ceramics fabricated by sol-gel method have a good application prospect for dental restorations.