1. Division of Prosthetic Dentistry, Maxillofacial UnitHalmstad Hospital Halmstad Sweden
2. Department of Prosthodontics/Dental materials science, Institute of Odontology, Sahlgrenska AcademyGöteborg University Sweden
3. Department of Periodontology, Faculty of OdontologyMalmö University Malmö Sweden
4. Department of Prosthetic Dentistry and Oral Function, Faculty of Dentistry, Institute of Clinical DentistryUniversity of Oslo Oslo Norway