1. Iasis Dental (Private Practice), 12241 Athens, Greece
2. Laboratory of Clinical Virology, Medical School, University of Crete, 71003 Heraklion, Greece
3. Biomedical Applications Unit, Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece
4. Department of Oral and Maxillofacial Surgery, University Hospital Attikon, 12462 Athens, Greece