1. ARDEC; Ariminum Odontologica; Rimini Italy
2. Center for Dental Medicine; University of Zurich; Zurich Switzerland
3. Faculty of Medicine and Dentistry; University of Murcia; Murcia Spain
4. Politecnico di Torino; Dipartimento di Scienza Applicata e Tecnologia-DISAT Istituto di Ingegneria e Fisica dei Materiali; Institute of Materials Engineering and Physics; Torino Italy
5. Faculty of Dentistry; University of Chieti; Chieti Italy
6. Faculty of Dentistry; University of Medical Science; La Habana Cuba