Received: 2 February 2021
Accepted: 19 June 2021
First Online: 10 July 2021
: The authors declare that they have no conflict of interest.
: All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. The study was approved by the Research Ethics Committee of the Tohoku University Graduate School of Dentistry (No. 2018-3-37).
: Informed consent was obtained in the form of an opt-out option on the Tohoku University Graduate School of Dentistry website where information about the conduct of the study, including the research objectives, were published.