Dental bulk block and method of manufacturing same

A dental bulk block comprising a crystalline phase in an amorphous glass matrix, wherein:

• the crystalline phase comprises at least one lithium silicate-based crystalline phase selected from the group consisting of lithium metasilicate and lithium disilicate, and a eucryptite crystalline phase;
• the dental bulk block is a functionally graded material having a crystalline size gradient with respect to a depth thereof and no interface at a point of change in a main crystalline size gradient value;
• when the dental bulk block is heat-treated at 820° C. for 40 minutes, the dental bulk block exhibits a characteristic peak of a spodumene crystalline phase in an X-ray diffraction analysis result graph;
• and
• when the dental bulk block is heat-treated at 820° C. for 2 minutes, the dental bulk block does not exhibit a characteristic peak of a spodumene crystalline phase in the X-ray diffraction analysis result graph, and
• wherein the crystalline size gradient is sloped such that the at least one lithium silicate-based crystalline phase has a mean grain size in a range of 0.05 to 1.0 μm, and the eucryptite crystalline phase has a mean grain size in a range of 1.0 to 4.0 μm, and
• wherein the amorphous glass matrix comprises 63.0 to 74.0 wt % of SiO2, 11.0 to 13.7 wt % of Li2O, 6 to 9 wt % of Al2O3, 1.5 to 3.5 wt % of K2O, and 2.0 to 4.0 wt % of P2O5, and wherein a molar ratio of SiO2/(Li2O+Al2O3) is 2.10 to 2.90.