1. Department of Prosthodontics, Department of Dentistry, Korea University Ansan Hospital, Ansan, Korea.
2. Cellbiocontrol Laboratory, Department of Medical Engineering, Yonsei University College of Medicine, Institute for Dental Research, Korea University, Korea University Guro Hospital, Seoul, Korea.
3. Department of Prosthodontics, School of Dentistry, Pusan National University, Yangsan, Korea.
4. Department of Prosthodontics, Department of Dentistry, Seoul Veterans Hospital, Seoul, Korea.