Affiliation: | 1. Public Dental Service, V?stra G?taland Region, , Stenungsund, Sweden;2. Department of Cariology, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, , Gothenburg, Sweden;3. Department of Preventive Dentistry, Public Dental Health, Uppsala County Council, , Uppsala, Sweden;4. Nordic School of Public Health NHV, , Gothenburg, Sweden |