The use of lithium silicate glass ceramic has proven itself in the field of dental technology because of its strength and biocompatibility. The strength can additionally be increased by adding a stabilizer from the group consisting of zirconium oxide, hafnium oxide, or mixtures thereof, to the starting raw materials (DE 10 2009 060 274 A1, WO 2012/175450 A1, WO 2012/175615 A1, WO 2013/053865 A2, EP 2 662 342 A1).
Lithium silicate glass ceramic materials, in particular if a blank contains lithium metasilicate as the main crystal phase, enable problem-free machining without high tool wear. To increase the strength, the lithium metasilicate is at least partially converted into lithium disilicate by subsequent heat treatment (DE 197 50 794 A1, DE 103 36 913 B4).
To produce dental restorations, it is known to press plastified ceramic material into a mold cavity present in a curable investment material (EP 1 484 031 B1, EP 0 231 773 A1).
DE 10 2010 108 171 A1 discloses a method to increase the strength of a form body consisting of lithium silicate glass ceramic. Lithium ions are replaced by alkali metal ions of greater diameter to generate a surface compressive stress.