Fluorine is a natural element that has an important effect on reducing dental caries. It can be used topically or systemically. Today, it is known that topical applications are more suitable to benefit from the protective effect of fluorine. Topical applications are even more effective with supervised brushing of the child's teeth twice a day. Fluoride application prevents demineralization of teeth and provides remineralization of tooth enamel. Thus, tooth decay is largely prevented. In general, it is recommended to apply twice a year.