1. Department of Periodontology, Oral Medicine and Oral Surgery Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of Health Berlin Germany
2. Department of Periodontology, Health Science Center University of Washington Seattle Washington USA
3. Department of Restorative Dentistry Periodontology, Endodontology, Preventive Dentistry and Pedodontics, Dental School, University Medicine Greifswald Germany
4. Department of Periodontology, Endodontology and Cariology, University Center for Dental Medicine Basel (UZB) University of Basel Basel Switzerland
5. Department of Reconstructive Dentistry, University Center for Dental Medicine Basel (UZB) University of Basel Basel Switzerland
6. Department of Periodontology, Operative and Preventive Dentistry University Hospital Bonn Bonn Germany