1 Assistant Professor, Department of Dentistry, Catholic University of Daegu School of Medicine, Daegu, South Korea; and Graduate student, Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, South Korea. Electronic address: jus2u@cu.ac.kr.
2 Professor, Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, South Korea.