Fluoride effects on the dentin-pulp complex

Abstract

Fluoride has been widely used to prevent dental caries by enhancing enamel remineralization and inhibiting demineralization. The increased use of fluorides and the reduction in dental caries have been accompanied by increased enamel fluorosis. Despite the great deal that is known about enamel fluorosis, not much is known on the effects of excess fluoride on forming dentin and its relationship to the tooth structure. Previous studies have described dentin hypomineralization with lower microhardness and disrupted hydroxyapatite crystal arrangement in human dentin exposed to fluoride at higher levels than clinically beneficial to prevent the dental caries. These effects appear to be dose related. More recently, dentin fluorosis has been linked to alteration in dentin matrix proteins synthesis, including reduced synthesis of dentin sialoprotein and dentin hypomineralization, while in vitro, fluoride has been shown to modulate type 1 collagen synthesis in the pulp in a dose-related manner. Further studies are necessary to fully understand the precise mechanism of dentin fluorosis. Nevertheless, if the dentin matrix formation and mineralization is affected by exposure to fluoride, this may affect the incidence and rate of progression of dentin caries.