Abstract
Machinability of high-strength glass-ceramics containing a large amount of fine calcium mica crystals was evaluated using conventional dental tools for dental prosthetic application in our CAD/CAM system.The glass-ceramics have excellent mechanical properties, i.e., high bending strength(～300MPa)and good hardness equivalent to a natural tooth enamel.These glass-ceramics were easy to machine using dental tools, such as diamond, carbide, and carborandom bars.In terms of chipping and ease of machining, the rotation speed shoud be<2, 500rpm under a machining condition in air, while, in flowing water, a speed of less than 20, 000rpm could be used.The machinability reveals that the glass-ceramics are appropriate material for the dental CAD/CAM system.
