*Kazuko Kagawa1, Miyuki Yokoi1, Hitoshi Abekura1, Masamichi Kato1, Fumiko Nishio2, Hanako Umehara1, Chihiro Yoshiga1, kaien Wakamatsu1, Koji Morita1, Kazuya Doi1, Kazuhiro Tsuga1
(1. Department of Advanced Prosthodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, 2. Department of Fixed Prosthodontics, Kagoshima University Graduate School of Medical and Dental Sciences)