1. Dental Biomaterials Adverse Reaction Unit, NORCE Norwegian Research Centre AS, Bergen, Norway
2. Department of Clinical Dentistry, University of Bergen, Bergen, Norway
3. Department of Community Medicine, Faculty of Health Sciences, The National Research Center in Complementary and Alternative Medicine (NAFKAM), UiT The Arctic University of Norway, Tromsø, Norway
4. Research Unit for General Practice, NORCE Norwegian Research Centre AS, Bergen, Norway
5. Department of General Practice, Institute of Health and Society, University of Oslo, Oslo, Norway
6. Institute for Applied Epistemology and Medical Methodology, University of Witten/Herdecke, Freiburg, Germany