Topical fluorides, such as varnishes, NaF, SnF2and APF are used as preventive reagents because of their remineralization and antimicrobial abilities. It can also be found in many dental and oral care products, such as toothpaste, mouthwash, and gels. In addition, fluoride intake through drinking water can also be obtained. It is believed that the anticaries effect of fluoride is due to its ability to protect the hard tissues of the teeth and inhibit bacterial growth and metabolism. The fluoride in saliva can be absorbed onto the surface of the apatite crystals which makes the teeth more resistant to the acidic environment of the oral cavity, thereby preventing the demineralization process, when the pH is low, Fluor hydroxyapatite can still tolerate the critical pH of hydroxyapatite, there are 5.5 and can increase the remineralization process. However, irrational use of fluoride can cause several complications such as dental fluorosis, natural fluorosis, neurotoxicity and others. This book emphazise on the management of the app;ication of flourides used in pediatric dentistry.