Fluoride application may lead to the risk of dental fluorosis in children, but overall the advantages outweigh the disadvantages. Fluoride has a better effect on preventing dental caries, it can remineralize the surface of the teeth, thus enhancing the strength of the child’s teeth and stopping the further development of dental caries, but a small number of children may accidentally swallow the fluoride when applying fluoride, which will lead to the emergence of dental fluorosis. Therefore, it is recommended that children under the age of three should not apply fluoride as much as possible, because at this time the children are small and can not fully cooperate with the doctor, it is easy to accidentally swallow fluoride, resulting in the emergence of dental fluorosis, and children over the age of three need to choose a regular hospital when applying fluoride treatment.