Enamel.

Abstract

The aim of this study was to test whether dental fluorosis can be produced by administration of chronic doses offluoride during only the post-secretory stage of enamel mineralization. Eight control and eight experimental pigs matched by weight and litter were fed a lowfluoride diet (<0.05 mg F-/kg b.w. daily) from weaning to slaughter at 14 months. The test group received an oral dose of 2 mg F/kg b.w. per day from 8 months of age. Lowerfourth pre-molars were at the post-secretory stage at the start offluoride administration (confirmed by tetracycline marker) and were just erupting at slaughter. All of the fourth pre-molar teethfrom the test group developed diffuse enamel hypomineralization indistinguishable from human fluorosis. No such lesions were seen in any of the teethfrom the control animals. It was concluded that enamel fluorosis may be caused by fluoride exposure in the maturation phase only. The pathogenic mechanism may be an effect either on the selective loss ofprotein or on the influx of mineral, both of which occur during the post-secretory or maturation stage of enamel formation.