1. Clinic of Periodontology, Borås Public Dental Service Region Västra Götaland Sweden
2. Research and Development Unit Borås Sweden
3. Department of Prosthodontics, Gerodontology and Oral Rehabilitation Graduate School of Dentistry Osaka University Osaka Japan
4. Department of Health Sciences Kristianstad University Kristianstad Sweden
5. Department of Health Blekinge Institute of Technology Karlskrona Sweden
6. School of Dental Science Trinity College Dublin Ireland
7. Faculty of Dentistry The University of Hong Kong Hong Kong SAR China