1. Periodontology Department, School of Dentistry, University of Granada, Colegio Máximo, s/n 18071 Granada, Spain
2. Biomedical Department of Internal Medicine & Medical Specialties, University of Palermo, Italy
3. Periodontology Unit & Division of Clinical Research, Eastman Dental Institute & Hospital, University College London (UCL), London, UK
4. Euro–Mediterranean Institute of Science & Technology, Palermo, Italy