[Series: Caries prevention in historical perspective. Fluoride].

Shortly after the Second World War it became known in the Netherlands that fluoride can contribute to the prevention of dental caries. As to how this effect was achieved, opinions differed. Initially, the dominant the view was that fluoride had to be absorbed into the enamel and dentine during tooth formation to make the teeth resistant to caries. Later it was discovered that decalcification of the enamel is inhibited if fluoride is present in the dental plaque. While in the beginning water fluoridation was considered to be the most effective measure to prevent caries, the current position is that tooth brushing with fluoride toothpaste plays the most important role in caries prevention.