[1
]
Faculty of Dentistry, The University of Hong Kong, Hong Kong.
[2
]
Faculty of Dentistry, The University of Hong Kong, Hong Kong; College of Stomatology,
Anhui Medical University, Hefei, China.
[3
]
College of Stomatology, Anhui Medical University, Hefei, China. Electronic address:
ql-li@126.com.
[4
]
Faculty of Dentistry, The University of Hong Kong, Hong Kong. Electronic address:
chchu@hku.hk.