Affiliation: | (1) Institute of Dental Materials, Chung-Shan Medical University, Taichung, 402 Taiwan, Republic of China;(2) Institute of Stomatology, Chung-Shan Medical University, Taichung, 402, Taiwan, Republic of China;(3) Dental Department, Chung-Shan Medical University Hospital, Taichung, 402 Taiwan, Republic of China |