Study on rotary ultrasonic machining of sintered zirconia dental ceramics

With the presintered zirconia ceramics widely used in prosthodontic, more and more problems were exposed, such as difficult to control shrinkage, high fracture rate and so on. A new method which used ultrasonic vibration assisted machining sintered zirconia ceramics was proposed. Machining sintered zirconia ceramics with rotary ultrasonic machining and diamond grinding was studied in this paper. Effects of spindle speed on cutting force, edge chipping size and subsurface damage were obtained. Compared with diamond grinding, the assistant for ultrasonic vibration not only reduces the cutting force and subsurface cracks significantly, but olso restrains the edge chipping effectively. Therefore, rotary ultrasonic machining might be the new low-damage method for sintered zirconia ceramics.