Funding for this research was provided by:
Supported by Qingdao Key Health Discipline Development Fund.
Received: 3 October 2021
Accepted: 11 January 2023
First Online: 27 January 2023
: This article does not contain any studies with human participants or animals performed by any of the authors. This study was approved and supervised by the ethics committee of the Qingdao Stomatological hospital Affiliated to Qingdao University.
: All the authors agree to publishing in EJMR.
: The authors declare no conflict of interest.