1. Department of Surgical Sciences, University of Turin C.I.R. Dental School, Turin, Italy.
2. Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy.
3. Department of Periodontology, Institute of Oral Bioscience, Jeonbuk National University School of Dentistry, Jeonju, Korea.
4. Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea.