1. Operative Unit of Dentistry; University-Hospital of Ferrara; Ferrara Italy
2. Research Centre for the Study of Periodontal and Peri-implant Diseases; University of Ferrara; Ferrara Italy
3. Operative Unit of Dentistry and Maxillofacial Surgery; Department Integrated Activity-Specialist Surgeries; University-Hospital of Modena; Modena Italy
4. Department of Specialistic Surgeries Head-Neck; University of Modena and Reggio Emilia; Modena Italy
5. Department of Periodontics; School of Dentistry; West Virginia University; Morgantown West Virginia
6. Private Practice Torre Pedrera; Rimini Italy
7. Center of Clinical Epidemiology; University of Ferrara; Ferrara Italy