“EDGE TOUGHNESS” AND MATERIAL PROPERTIES RELATED TO THE MACHINING OF DENTAL CERAMICS

Abstract Seven dental ceramic compositions, including zirconia, glass-infused alumina, polycrystalline alumina, porcelain and three different machinable glass ceramics (MGC's) were tested for edge flaking. The chosen load range encompassed the forces typically associated with machining operations for these materials. The results were examined with regard to material properties and the applicability of a parameter defined as “edge toughness” to machin-ability. It was determined that a non-linear low-load chipping relationship may be more relevant to machinability than the “edge toughness” parameter calculated from the high-load linear region.