1. Department of Surgery, Unit of Dentistry and Oral Surgery; University of Pisa; Pisa; Italy
2. Department of Periodontology; University of Florence; Florence; Italy
3. Department of Experimental Pathology, Medical Biotechnologies, Infectious Diseases and Epidemiology; University of Pisa; Pisa; Italy
4. European Research Group on Periodontology; Genova; Italy