AL2O3-MODIFIED AND ZRO2-MODIFIED DENTAL GLASS-CERAMICS

Castable machinable glass-ceramics have been widely considered as aest hetic materials for dental restoration. In order to extend their appli cations to bridge-work fabrication, it is necessary to increase their fracture strength and fracture toughness. The effects of ziconia and a lumina additions on the properties of glass-ceramics, especially on th e mechanical properties were studied. It was found that appropriate ad dition of alumina increases the bending strength due to aluminium stre ngthening the glass-ceramic by means of incorporation into the glass n etwork. However, additions of ziconia fail to show promising results o n the mechanical property. The evolution of recrystallization and the associated microstructure were also studied and are discussed.