1. Section for Periodontology, Microbiology and Community Dentistry; Department of Odontology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
2. Department of Infectious Diseases and Rheumatology; Institute for Inflammation Research; Rigshospitalet; Copenhagen University Hospital; Copenhagen Denmark
3. Department of Applied Oral Sciences; Center for Periodontology; The Forsyth Institute; Cambridge Massachusetts USA