1. 'Conservative Dentistry, Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong, SAR, China
2. Department of Dental Materials, University of Granada, Spain
3. Bauru School of Dentistry, University of São Paulo, Brazil
4. 'Conservative Dentistry, Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong, SAR, China,
5. Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, GA, USA