1. Department of Prosthodontics, School of Dentistry, ITRD, Kyungpook National University, Daegu, Republic of Korea.
2. Department of Microbiology and Immunology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
3. Department of Periodontics and Endodontics, State University of New York at Buffalo, Buffalo, New York, United states of America.
4. Department of Dentistry, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
5. Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea.