1. School of Dentistry, International Medical University, Kuala Lumpur, Malaysia.
2. Department of Endodontics, University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA, USA.
3. School of Dentistry, Faculty of Clinical and Biomedical Sciences, University of Central Lancashire, Preston, United Kingdom.
4. Department of Endodontology, King’s College London Dental Institute, London, United Kingdom.