1. Section of Implant and Rehabilitative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
2. Division of Advanced Dental Devices and Therapeutics, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
3. Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan
4. Department of Physics, Faculty of Science, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan