1. Department of Operative Dentistry; Nihon University School of Dentistry; Tokyo Japan
2. Department of General Dentistry; Creighton University School of Dentistry; Omaha NE USA
3. Department of Restorative Dentistry; Oregon Health & Science University School of Dentistry; Portland OR USA
4. Department of Adult Restorative Dentistry; University of Nebraska Medical Center College of Dentistry; Lincoln NE USA