1. Unit of Periodontology, University Medicine, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany
2. Department of Prosthetic Dentistry, Gerodontology, and Biomaterials, Center of Oral Health, University Medicine, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany
3. Institute of Clinical Chemistry and Laboratory Medicine, University Medicine, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany
4. Institute of Community Medicine, University Medicine, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany
5. Department of Oral Surgery, School of Dentistry, University of Birmingham, Birmingham, UK