Materials and methods
This randomized, parallel, two- arm clinical trial was conducted in nurseries of rural areas around Alexandria, Egypt, from March 2022 to March 2023. Ethical approval was obtained from the Research Ethics Committee at the Faculty of Dentistry, Alexandria University, Egypt (#0272–07/2021). The research purposes and procedures, risks and benefits were explained to the parents and they were asked to sign an informed consent form. The study was conducted in accordance with the Helsinki declaration for human research [