Funding for this research was provided by:
Sichuan Province Science and Technology Support Program (2017RZ0036)
Text and Data Mining valid from 2019-07-17
Received: 29 October 2018
Accepted: 2 July 2019
First Online: 17 July 2019
Ethics approval and consent to participate
: The research protocol was censored and approved by the Ethic Committee of West China Hospital of Stomatology, Sichuan University (Approval No.WCHSIRB-D-2016-084R1). All methods were performed in accordance with the relevant guidelines and regulations. We have read the Helsinki Declaration and have followed the guidelines in this investigation.
: The authors confirm that the content of the manuscript has not been published or submitted for publication elsewhere.
: The authors declare that they have no competing interests.