Developing superior materials to replace damaged teeth is a perpetual challenge, given that teeth are the strongest tissues in our bodies. Glass ceramic (GC) materials stand as dominant choices for dental restoration. Among these, lithium disilicate-based GC is well-known, offering a balance between strength and translucency; however, there is room for strength improvement. On the other hand, zirconia full ceramics exhibit superior flexural strength and toughness but lack promising translucency. The key question is whether it's possible to discover a material that can seamlessly blend the translucency of GC with the strength of zirconia ceramics. Our objective is to formulate and fabricate a straightforward GC system featuring nano-zirconia within an amorphous silica matrix, achieved through powder processing and advanced sintering techniques. By precisely controlling crystalline size, 3D microstructure, concentration, and grain boundaries, we anticipate achieving excellent translucency, high flexural strength, and toughness.

The raw powders were synthesised by the sol-gel method. Then the powders were sintered by spark plasma sintering (SPS-825, Japan). The samples were investigated by different material characterization techniques. The fracture energy and strength of interphases were calculated by density functional theory.

In summary, the translucent, robust, and tough nano-zirconia-silica glass-ceramics were prepared through a powder-based approach. These materials exhibit flexural strength exceeding 1 GPa and toughness surpassing 10 MPam1/2. It's worth noting that mechanical strength is influenced not only by the composition but also by the size and 3D tomography of the nanocrystals within the amorphous matrix. Additionally, the interface between zirconia-zirconia and zirconia-silica plays a pivotal role in determining toughness.