It is best to apply fluoride half an hour before eating. Dental fluoride, which is a fluorine-containing substance, fluoridates the surface of each tooth to form a protective film on the surface of the tooth to prevent caries, is a method of dental care for children, and it is generally recommended that fluoride treatment be carried out twice a year. It is generally recommended to have fluoride treatment twice a year. After fluoride treatment, it is recommended not to drink or eat for half an hour to avoid destroying the fluoride protective film and affecting the effect of fluoride application. Try to give your child softer food or fluids that are cool or lukewarm, not too hot or too hard. Do not brush or floss for at least 4-6 hours, and remind your child to spit out the mouthwash in his or her mouth when brushing and not to swallow it. Regular oral checkups and fluoride applications can help minimize your child’s risk of dental caries, and treat them aggressively when necessary and as prescribed by your doctor.