Glass-ceramic and its production and use

摘要

The invention encompasses a glass-ceramic comprising a continuous glass phase and a crystal phase comprising tetragonal leucite, wherein the glass-ceramic has a crack-free glass phase and a crystal phase comprising leucite crystals distributed essentially homogeneously in the glass phase. The crystal phase has a particle size distribution made of from about 5% to about 70% of a first group of leucite crystals having particle sizes of <1 mum and from about 30% to about 95% of a second group of leucite crystals having particle sizes of >=1 mum. The proportion of Li₂O in the glass-ceramic is preferably below 0.5% by weight. It is preferred that not only the glass phase but also the crystal phase is essentially free of cracks. The corresponding glass-ceramics are particularly suitable for use in the dental sector, in particular as facing ceramics.