1 Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry, Aristotle University of Thessaloniki, Agiou Dimitriou 195, 541 24, Thessaloniki, Greece. mnikifor@yahoo.gr.
2 Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry, Aristotle University of Thessaloniki, Agiou Dimitriou 195, 541 24, Thessaloniki, Greece.
3 Department of Oral Surgery, Implantology and Roentgenology, School of Dentistry, Aristotle University of Thessaloniki, Agiou Dimitriou 195, 541 24, Thessaloniki, Greece.
4 School of Agriculture, Laboratory of Agronomy, Aristotle University of Thessaloniki, Agiou Dimitriou 195, 541 24, Thessaloniki, Greece.