Ivar Krohn-Dale1, Olav E. Bøe 2,3 Morten Enersen and Knut N. Leknes1
1 Department of Clinical Dentistry – Periodontotics, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway; 2Department of Clinical Dentistry – Dental Research, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway; 3Faculty of Dentistry, Institute for Oral Biology, University of Oslo, Oslo, Norway
J Clin Periodontol 2012