Ethics approval and consent to participate
Informed written consent was obtained from all study participants (children and their parents). This study was carried out in agreement with the Federal Act on Research involving Human Beings (Human Research Act; article 2, paragraph 2). The authorisation from the ethics committee was waived (Zurich cantonal ethics commission, BASEC-2022-00962). Children and parents gave their written consent for the use of the molars for research purposes.