Funding for this research was provided by:
National Natural Science Foundation of China (81571010)
Key Technology Research and Development Program of Shandong (2018GSF118199)
Received: 11 December 2019
Accepted: 23 June 2020
First Online: 27 July 2020
Ethics approval and consent to participate
: The experimental protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Human Ethics Committee of Shandong University Dental School (No.201910005). Written informed consent was obtained from individual or guardian participants.
: Not applicable.
: The authors declare that they have no competing interests.