1. Research Centre for the Study of Periodontal and Peri-Implant Diseases; University of Ferrara; Ferrara Italy
2. Department of Medical and Surgical Specialties; University of Padova; Padova Italy
3. Department of Periodontics and Oral Medicine; School of Dentistry, University of Michigan; Ann Arbor MI USA
4. Department of Clinical and Experimental Medicine; University of Ferrara; Ferrara Italy