Topical application of fluorides on teeth. New concepts of mechanisms of interaction

Prevention of caries in exposed root surfaces constitutes an important clinical problem. It is thus important that clinicians involved with periodontology have an insight into fluoride prophylaxis. The understanding of the cariostatic mechanism of fluoride has improved during recent years. The aim of the present review is to give a short account of the present concept. Calcium fluoride appears to be the only product which is formed on enamel, dentin or cementum during brief topical treatments with fluoride or use of toothpaste containing fluoride. This calcium fluoride is stable in the oral environment; this is contrary to what was believed until recently. The calcium fluoride constitutes a pH-dependent reservoir of fluoride which releases fluoride when pH drops. The practical consequences of this concept is discussed.