1. Division of Gerodontology and Removable Prosthodontics School of Dental Medicine University of Geneva Geneva Switzerland
2. Department of Prosthodontics and Materials Science Center for Dental, Oral and Maxillofacial Surgery University of Leipzig Leipzig Germany
3. Department of Operative Dentistry and Periodontology Centre of Dental Medicine University of Cologne Cologne Germany
4. Medical Research Department Colgate Palmolive Company Hamburg Germany
5. Colgate Palmolive Dental Health Unit Williams House Manchester Science Park Manchester UK
6. Department of Rehabilitation and Geriatrics University Hospitals of Geneva Geneva Switzerland