1. ETEP (Etiology and Therapy of Periodontal and Peri‐implant Diseases) Research Group, Faculty of Dentistry University Complutense of Madrid Madrid Spain
2. Department of Periodontology Institute of Dentistry, University of Turku Turku Finland
3. The Wellbeing Services County of Southwest Finland, Oral Health Care Turku Finland
4. Department of Periodontology Aix‐Marseille Université Marseille France
5. Medical University of Innsbruck University Hospital of Conservative Dentistry and Periodontology Innsbruck Austria
6. Clinic of Conservative Dentistry and Periodontology University of Kiel Kiel Germany
7. Faculty of Dental Medicine, Department of Community Dentistry, Hadassah Medical Center Hebrew University of Jerusalem Jerusalem Israel
8. Department of Periodontology Malmö University Malmö Sweden
9. Department of Periodontology, Faculty of Dental Medicine, Hadassah Medical Center Hebrew University of Jerusalem Jerusalem Israel
10. Department of Periodontology, Center for Dentistry and Oral Medicine (Carolinum) Goethe University Frankfurt Frankfurt Germany