Fluoride is an essential trace element of the human body. Fluoride can prevent dental caries; its mechanisms in caries prevention mainly include enamel solubility reduction and enamel remineralization enhancement. Fluoride can also affect tooth morphology and inhibit bacterial metabolism and plaque formation. This element has been used to prevent dental caries in systemic and topical ways. Systemic fluoridation includes the following methods: water fluoridation, where appropriate fluoride concentrations are added to drinking water to prevent tooth decay; salt fluoridation, where fluoride is added to domestic salt to control and prevent dental caries; and milk fluoridation, where fluoride is added to milk as a vehicle to provide additional fluoride and prevent dental caries. Fluoride tablets and drops combine both local and systemic effects. Each systematic fluoridation method for caries prevention presents advantages and disadvantages. Different countries and areas should select the most appropriate systemic fluoridation method according to their situation. Topical fluoride use includes personal use of fluorides for caries prevention, such as fluoridated toothpastes, fluoride mouth wash, fluoride floss, and tea gargle. Many forms of professional fluoride agents are available, including fluoride solution, fluoride varnishes, fluoride gels, fluoride foam, fluoride-containing filling materials, and fluoride-releasing materials. Topical use of fluoride for caries prevention is effective; thus it is very commonly used in clinics and families.
