1. School of Mechanical Engineering, Kyungpook National University, Daegu 41566, South Korea
2. Department of Biomaterials and Prosthodontics, Kyung Hee University Hospital at Gangdong, School of Dentistry, Kyung Hee University, Seoul 05278, South Korea
3. Department of Prosthodontics, Dental Research Institute, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan 50612, South Korea