1. Department of Endodontics, Comprehensive Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
2. Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
3. Periodontology and Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
4. Oral Microbiomics and Infection, School of Dentistry, University of Queensland, Brisbane, Australia.