1. Center for Oral Rehabilitation, Public Dental Services, Falun, Sweden;
2. Department of Surgical Sciences, Oral and Maxillofacial Surgery, Medical Faculty, Uppsala University, Uppsala, Sweden;
3. School of Education, Health and Social Studies, Falun, Sweden;
4. Center for Public Dental Services, Falun, Sweden;
5. Public Dental Services, Gävleborg, Sweden;
6. Center for Clinical Research, Uppsala University/Region Gävleborg, Gävle, Sweden