1. Department of General Dental Practice and Oral and Maxillofacial Imaging, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia
2. Academic Unit of Oral and Maxillofacial Surgery and Medicine, School of Clinical Dentistry, University of Sheffield, Sheffield, UK
3. Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
4. Academic Unit of Restorative Dentistry, School of Clinical Dentistry, University of Sheffield, Sheffield, UK