1. Department of Surgical and Integrated Diagnostic Sciences, University of Genova, 16132 Genoa, Italy
2. Therapeutic Dentistry Department, Institute of Dentistry, I.M. Sechenov First Moscow State Medical University, Trubetskaya Str., 119992 Moscow, Russia
3. Dental Department, University Trisakti, Jakarta 11440, Indonesia
4. Department of Biomedical Surgical and Dental Sciences, University of Milan, 20142 Milan, Italy