1. Department of Conservative Dentistry; The Catholic University of Korea, St. Paul's Hospital; Seoul; Korea
2. Department of Dental Hygiene; Shingu University; Seongnam; Korea
3. Department of Biomaterials & Prosthodontics; Kyung Hee University Dental Hospital at Gangdong; Seoul; Korea
4. Department of Endodontics; University of Western Australia, Crawley; Australia
5. Department of Maxillofacial Tissue Regeneration; School of Dentistry and Institute of Oral Biology; Kyung Hee University; Seoul; Korea