1. University of Tampere; School of Health Sciences; Voimakatu 4 A 12 (home) Tampere Finland FI-33100
2. Tampere University Hospital; Department of Oral and Dental Diseases; PO Box 2000 Tampere Finland FI-33521
3. The University of Manchester; Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health; JR Moore Building Oxford Road Manchester UK M13 9PL
4. Ministry of Social Affairs and Health; Health Department; P.O. Box 33 FIN-00023 Government Helsinki Finland
5. THL (National Institute for Health and Welfare); PO Box 30 Helsinki Finland 00271
6. University of Copenhagen; Department of Public Health; Copenhagen Denmark
7. Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester; Cochrane Oral Health; JR Moore Building Oxford Road Manchester UK M13 9PL