1. Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, Republic of Korea.
2. Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
3. Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Tsurumi-ku, Yokohama-shi, Japan.