1. Clinic of Reconstructive Dentistry, Center of Dental Medicine University of Zurich Zurich Switzerland
2. Centre for Oral Clinical Research, Institute of Dentistry, Barts and The London School of Medicine and Dentistry Queen Mary University of London London UK
3. Department of Life, Health and Environmental Sciences University of L'Aquila L'Aquila Italy
4. Department of Conservative Dentistry, Faculty of Dentistry University of Chile Santiago Chile