1. Department of Conservative Dentistry, Pusan National University School of Dentistry, Yangsan, Korea.
2. Department of Bioscience Research, University of Tennessee Health Science Center College of Dentistry, Memphis, USA.
3. Area of Endodontics, the University of Hong Kong Faculty of Dentistry, Hong Kong SAR, China.
4. Department of Conservative Dentistry, Kyungpook National University School of Dentistry, Daegu, Korea.