Received: 8 September 2019
Accepted: 1 April 2020
First Online: 15 April 2020
Ethics approval and consent to participate
: We excluded patients who did not want to participate in this study via the opt-out method on the dental clinic website. The ethical committee of the Japanese Society of Periodontology approved this clinical cross-sectional study in a matched collective (JSP2019001) and the need for written consent would be waived via the opt-out method of the dental clinic website.
: Not applicable.
: The authors declare that they have no competing interests in this study. No financial or non-financial interests influenced the interpretation of the data or presentation of the information.