1 Department of Prosthodontics, Dongtan Sacred Heart Hospital, Hallym University, Dongtan, Republic of Korea.
2 Department of Oral and Maxillofacial Pathology, and Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, 1 Heogi-dong, Dongdaemun-gu, Seoul 130-701, Republic of Korea.
3 Department of Oral Medicine, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
4 College of Pharmacy, Wonkwang University, Iksan 570-749, Republic of Korea.