ULTRAHIGH SPEED MICROGRINDING OF DENTAL CERAMICS - TECHNICAL COMMUNICATION

Theoretical models and experimental results on machining of industrial ceramics have shown that machining at high speeds reduces the grit depths of cut, thus reducing the contact forces and resulting in a reduced possibility of detrimental chipping and subsurface machining damage. A new ultrahigh speed micro-spindle developed for micromachining at rotational speeds as high as 500,000rpm was used for microgrinding of dental ceramics. Several ceramics used for preparation of dental restorations were cut with diamond tools at ultrahigh speeds. The propensity for generation of machining-related damage, such as surface and subsurface microcracks, were greatly reduced by machining at ultrahigh speeds and high feed rates.