1. Department of Conservative Dentistry, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Korea.
2. Department of Nutritional Science and Food Management, Ewha Womans University Health Science College, Seoul, Korea.
3. Department of Oral and Maxillofacial Surgery, Korea University Anam Hospital, Seoul, Korea.
4. Department of Dental Biomaterials Science, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Korea.