1. Department of Biomedical, Surgical, and Dental Science Università degli Studi di Milano Milan
2. IRCCS Istituto Ortopedico Galeazzi Milan Italy
3. Department of Oral Surgery Institute of Dentistry, I. M. Sechenov First Moscow State Medical University Moscow Russia
4. Department of Periodontics and Implantology University Of Bern Bern Switzerland