1. Oral Health Science Center, Tokyo Dental College; Tokyo Japan
2. Department of Oral and Maxillofacial Implantology; Tokyo Dental College; Tokyo Japan
3. Department of Anatomy; Tokyo Dental College; Tokyo Japan
4. Department of Removable Partial Prosthodontics; Tokyo Dental College; Tokyo Japan
5. Division of Materials & Manufacturing Science, Graduate School of Engineering; Osaka University; Osaka Japan