1. Department of Dental Biomaterials, Institute of Biodegradable Materials, School of Dentistry, Jeonbuk National University, Jeonju-si 54896, Jeollabuk-do, South Korea
2. Department of Prosthodontics, School of Dentistry, Jeonbuk National University, 567 Baekje-daero, Jeonju 54896, South Korea