Funding for this research was provided by:
the education reform project of Sichuan University in the new century (SCU8375, SCU8378)
Received: 19 October 2018
Accepted: 21 January 2019
First Online: 4 February 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of the Ethics Committee of the College of West China Hospital of Stomatology, Sichuan University (WCHSIRB-D-2018-092). Written informed consent was obtained from all the participating students.
: Written consent from the participants was obtained.
: Authors do not have any competing interest.
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