1. Prosthodontic Specialist Clinic, Public Dental Service of Västerbotten, Region Västerbotten, Umeå, Sweden;
2. Dental Material Science, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden;
3. Prosthetic Dentistry, Department of Odontology, Faculty of Medicine, Umeå University, Umeå, Sweden