1. Unit of Periodontology, Endodontology and Restorative Dentistry, Department of Medical Biotechnologies University of Siena Siena Italy
2. Unit of Periodontology UCL Eastman Dental Institute London UK
3. Department of Periodontology, Faculty of Dentistry University of Oslo Oslo Norway
4. Unit of Dermatology, Department of Medical, Surgical and Neurological Science University of Siena Siena Italy