Chapter 2. High Expansion Feldspar Porcelain and Magnesia Core Materials

Summary

Feldspar porcelains have been used in dentistry for denture teeth since the early 1800s and more recently as veneering for crown and bridgework. Porcelains for veneering metal substructures have higher thermal expansion values due to an increase in leucite content. Recently high expansion magnesia ceramics have been developed which serve as an inner core reinforcement for the construction of all ceramic crowns. The construction of a feldspar crown is done by hand using finely ground factory-fritted porcelains and firing to produce vitreous sintering.