1. Dental Materials Laboratory, Department of Restorative Dentistry, Indiana University School of Dentistry, 1121 West Michigan Street, Indianapolis, IN 46202-5186, USA
2. Department of Mechanical Engineering. Kokushikan University, Faculty of Engineering, Tokyo, Japan
3. Prosthdontics, Department of Restorative Dentistry, Indiana University School of Dentistry, 1121 West Michigan Street, Indianapolis, IN, 46202-5186, USA