Clinical and structural features and possible pathogenic mechanisms of dental fluorosis

Abstract

ABSTRACT— The aim of the present review has been to give a survey of our present knowledge concerning dental fluorosis and to discuss possible pathogenic mechanisms of this disease. Based on a discussion of the principles behind the Community Index of dental fluorosis it is stressed that absence of harmful community effects should not be confused with a complete absence of fluoride‐induced biological changes. The index values apply to communities and they do not equivalate individual diagnosis. Structurally, an increase in fluoride intake results in an increase in degree and extent of porosity of the enamel. Further, dentin changes may be observed. It is stressed that the clinical and structural features should be kept in mind when possible pathogenic mechanisms of dental fluorosis are discussed. It is obvious that the enamel changes described may not necessarily be a result of a fluoride damage of secretory ameloblast as commonly assumed. Thus, structural changes similar to those of enamel fluorosis may result from an impairment of the process of enamel maturation. This can either be due to a fluoride‐induced change in composition or rheologic features of enamel matrix, or be a result of a disturbance of the cellular processes during enamel maturation. In addition, it is suggested that fluoride may act directly on the poorly understood processes of mineralization in vivo. Finally, results indicate that fluoride interferes with calcium homeostasis, and it cannot be entirely excluded that dental fluorosis may be a result of a more generalized effect of fluoride. It is concluded that much more basic research on fluoride metabolism and formation of mineralized tissues is needed to better understand the effect of fluoride on dental hard tissues.