[Controversial caries prevention using fluorine].

Fluorine as an essential trace element is necessary for life. The artificial increase of the natural fluoride-content of drinking water up to a maximum of one milligram per litre has been proved a prophylactic step against dental caries. The available material is examined to find out how far side effects of this fluoride concentration as well as any higher fluoride doses can be brought in connection with special defects and patterns of diseases. A comprehensive review of scientific findings concerning physiological reactions caused by fluoride is given.