1. ETEP (Etiology and Therapy of Periodontal and Peri-implant Diseases) Research Group, University Complutense of Madrid, Madrid, Spain
2. Department of Periodontology, Faculty of Dental Medicine, Hadassah and the Hebrew University Medical Center, Jerusalem, Israel
3. Biomedical Research Institute Sant Pau (IIB Sant Pau), Sardenya Primary Health Care Center, Barcelona, Spain
4. Periodontal Research Group, and Birmingham NIHR Biomedical Research Centre in Inflammation, Institute of Clinical Sciences, College of Medical & Dental Sciences, The University of Birmingham, Birmingham, UK
5. Birmingham Community Healthcare NHS Foundation Trust, Birmingham, UK
6. Institut für Allgemeinmedizin, Medizinische Fakultät der Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
7. Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, School of Dentistry, University of Pisa, Pisa, Italy
8. Oxford Primary Care, Radcliffe Primary Care Building, ROQ, University of Oxford, Oxford, UK
9. Dental Faculty, University of Strasbourg, Strasbourg, France
10. Department of General Practice and Family Medicine, University Medical Center Göttingen, Göttingen, Germany
11. Department of Periodontology, Operative and Preventive Dentistry, University Hospital Bonn, Bonn, Germany
12. Dr. Odinaka’s Clinic, Bodø, Norway
13. Department of Periodontology, Faculty of Dentistry, National & Kapodistrian University of Athens, Athens, Greece
14. Department of Family Medicine, Ankara University School of Medicine, Ankara, Turkey
15. Department of Medicine, University of Vic–Central Catalonia University, Vic, Spain
16. Primary Health Care Service, Althaia Foundation–Healthcare and University Network, Manresa, Spain
17. Department of Family Medicine, Jagiellonian University Medical College, Krakow, Poland
18. Department of Family Medicine, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel