Methods
RECRUITMENT
The study design was a three-arm parallel group, randomized clinical trial that allocated subjects into a 1:1:1 ratio. The trial was approved by the Institutional Review Board of the Faculty of Dentistry/Faculty of Pharmacy, Mahidol University (No. MU-DT/PY-IRB 2019/005.1101) and registered in the Thai Clinical Trials Registry (No. TCTR20190315003) on 15/03/2019.The research purposes, procedures, risks, and benefits of the study were explained to the parents or guardians of the participants before they signed informed consent forms. All participants were free to see a dentist and had rights to withdraw from the study for any reason at any time during the trial. Informed consent was obtained from the parent or guardian of each child prior to commencing the intervention. Participant recruitment and data collection were conducted from March 2019 to October 2020.