Funding for this research was provided by:
Suomen Hammaslääkäriseura Apollonia
Päivikki ja Sakari Sohlbergin Säätiö
Received: 7 June 2021
Accepted: 23 November 2021
First Online: 7 December 2021
: The participation was voluntary. Each participant or his/her closest proxy gave written informed consent. The City of Helsinki and the Ethics Committee of the Hospital District of Helsinki and Uusimaa approved the study protocol. This study adheres to the guidelines of the Declaration of Helsinki.
: Not applicable.
: The authors declare no competing interests.