1. Department of Dental Materials, Dental Science Research Institute, Chonnam National University School of Dentistry, Gwangju, Korea
2. GnS International, Daejeon, Korea
3. Department of Oral Medicine, Seoul Veterans Hospital, Seoul, Korea
4. Department of Oral Medicine, Dental Science Research Institute, Chonnam National University School of Dentistry, Gwangju, Korea
5. Department of Oral Medicine, Chonnam National University Dental Hospital, Gwangju, Korea