1. Clinic for Fixed and Removable Prosthodontics and Dental Material Science; Center of Dental Medicine; University of Zurich; Zurich Switzerland
2. Center of Dental Medicine; University of Zurich; Zurich Switzerland
3. Division of Fixed Prosthodontics and Biomaterials; Center of Dental Medicine; University of Geneva; Geneva Switzerland
4. Institute of Mathematical Statistics and Actuarial Science; University of Berne; Berne Switzerland