1. Centre for Oral Clinical Research; Institute of Dentistry; Barts and The London School of Medicine and Dentistry; Queen Mary University London (QMUL); London UK
2. Institute for Community Medicine; University Medicine Greifswald; Greifswald Germany
3. Unit of Periodontology; Department of Restorative Dentistry, Periodontology, Endodontology, and Preventive and Pediatric Dentistry; University Medicine Greifswald; Greifswald Germany