Abstract: Fluoride is one of the possible essential trace elements in human body. Optimal fluoride level is benefit to the teeth and bone. Fluoride can also reduce dental decay by three mechanisms：reducing the solubility of tooth enamel in acid to make it more resistant to decay，remineralizing the tooth enamel that has been demineralized by acids produced and reducing acid production by dental plaque organisms. In China，use of fluoride includes systemic use and topical use. Topical fluoride application is frequently used in dental clinic and prevention programmes in communities，and it is one of safe and effective methods for caries prevention.

Key words: fluoride, enamel, caries prevention

摘要： 氟是人体可能必需的微量元素，适量摄入可对机体代谢产生积极影响。氟亦可通过降低釉质溶解度和促进再矿化、对微生物产生作用达到预防龋病的目的。氟化物应用可分为全身应用和局部应用。目前在我国，局部用氟已成为广泛使用、安全有效的防龋方法之一。

关键词: 氟, 牙釉质, 龋病预防