1. Department of Biomedical Sciences, Dentistry and Morphological and Functional Imaging, University of Messina, Messina
2. Multidisciplinary Department of Medical-Surgical and Dental Specialties, University of Campania “Luigi Vanvitelli”, Napoli, Italy
3. Department of Implantology, Faculty of Dentistry, University of Aldent, Tirana, Albania
4. Department of Prosthetic Dentistry, Dr D.Y. Patil Dental College and Hospital, Dr D.Y. Patil Vidyapeeth, Pimpri, Pune, India
5. Department of Medical and Surgical Science, Section of Dentistry, University of Catania
6. Private Practice, Catania, Italy