1. Gerodontology Section, Department of Prosthetic Dentistry and Materials Science, Leipzig University, Liebigstraße 12, 04103 Leipzig, Germany
2. Clinic of General, Special Care and Geriatric Dentistry, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, CH-8032 Zurich, Switzerland
3. Institute of Biometry and Clinical Epidemiology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany
4. Materials Science Section, Department of Prosthetic Dentistry and Materials Science, Leipzig University, Liebigstraße 12, 04103 Leipzig, Germany
5. University Research Priority Program “Dynamics of Healthy Aging”, University of Zurich, CH-8050 Zurich, Switzerland