Spinel glass-ceramic, method for the production thereof and shaped dental product containing the spinel glass-ceramic

A method for producing a spinel glass-ceramic, the method comprising:

• a) producing a starting glass containing the components of the spinel glass-ceramic, the components including:
• 30 to 45% by weight SiO2,
• 15 to 30% by weight Al2O3,
• 3 to 10% by weight MgO,
• 2 to 10% by weight P2O5,
• 8 to 20% by weight ZrO2 and/or TiO2,
• 0.1 to 15% by weight La2O3,
• 0.1 to 3.0% by weight B2O3, and
• 0.1 to 10.0% by weight of additives,
• the proportions of the components adding up to 100% by weight, and
• the spinel glass-ceramic not containing any high quartz solid solution phase;
• and
• b) subjecting the starting glass to at least one first heat treatment and then at least one second heat treatment
• wherein the at least one first heat treatment takes place at a temperature of 700° C. to 950° C. and wherein the at least one second heat treatment takes place at a temperature of 900° C. to 1200° C.

A shaped dental product containing a spinel glass-ceramic, the dental product including:

• a spinel glass-ceramic composed of a composition with the following components:
• 30 to 45% by weight SiO2,
• 15 to 30% by weight Al2O3,
• 3 to 10% by weight MgO,
• 2 to 10% by weight P2O5,
• 8 to 20% by weight ZrO2 and/or TiO2,
• 0.1 to 15% by weight La2O3,
• 0.1 to 3.0% by weight B2O3, and
• 0.1 to 10.0% by weight of additives,
• the proportions of the components adding up to 100% by weight, and
• the spinel glass-ceramic not containing any high quartz solid solution phase.