For a few decades, a decrease in the caries burden in all age groups has been observed in Germany. The regular use of fluoride preparations is described as the main reason for the caries decline. It is well established that topical fluoride application directly to the tooth surfaces in the oral cavity, in particular fluoride-containing toothpastes and fluoride varnishes, is responsible for the decline. Several mechanisms of action, such as the formation of a calcium fluoride layer, remineralization, and the effects on bacterial plaque, were determined to be responsible for the overall clinical effect. All these mechanisms can be effective on enamel and root dentin in patients of all ages. There is a dose-response relationship between the fluoride concentration in the applied preparations and the average caries reduction achieved.There are no general toxicological concerns about topical fluoride application. Fluoride toothpastes should be used from the eruption of the first deciduous tooth. The amount of toothpaste used should be limited to the recommended volumes to avoid the development of enamel fluorosis. The professionally performed application of highly concentrated fluoride varnishes, in addition to having a high caries-inhibiting effectiveness, also exhibits advantages in cases of increased caries risk and existing demineralization. This is also the case for the application on root dentin, where significant primary and secondary preventive effects have been demonstrated by application of highly concentrated fluoride preparations.