1. Department of Periodontology, Institute of Clinical Dentistry, Faculty of Dentistry University of Oslo Oslo Norway
2. Department of Biomaterials, Institute of Clinical Dentistry, Faculty of Dentistry University of Oslo Oslo Norway
3. Department of Experimental Trauma Surgery, Faculty of Medicine Justus‐Liebig University Giessen Giessen Germany
4. Periodontology University Complutense of Madrid Madrid Spain
5. Department of Prosthetics and Oral Function University of Oslo Oslo Norway