1. Department of Surgical and Morphological Science, Dental School, University of Varese, Via Giuseppe Piatti 10, 21100 Varese, Italy
2. Private Practice, 00193 Rome, Italy
3. Dental Research Division, Department of Periodontology, Guarulhos University, Praca Teresa Cristina 229, 07023070 Guarulhos, SP, Brazil
4. Division of Periodontics, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia