1. Department of Reconstructive Dentistry and Gerodontology School of Dental Medicine University of Bern Bern Switzerland
2. Comprehensive Dental Care The Nippon Dental University Niigata Hospital Niigata Japan
3. Department of Dental Materials Science School of Life Dentistry at Niigata The Nippon Dental University Niigata Japan
4. Division of Gerodontology and Removable Prosthodontics University Clinics of Dental Medicine University of Geneva Geneva Switzerland
5. Department of Geriatric Dentistry School of Dentistry Showa University Tokyo Japan