Enamel fluorosis in rat's incisor: S.E.M. and T.E.M. investigation.

Findings on the alterations taking place in the enamel have demonstrated that they are generally caused by a daily use of highly fluoridated drinking waters. According to that, the Authors have carried out an ultrastructural study on lower incisors of albino rats after administering for 60 days water with a fluorine concentration five times the normal one. The samples, studied under the S.E.M., showed a general slowing of both the deposition and the maturation phase as well as the presence of some hypomineralized areas even after eruption. All this suggested the possibility that the damages observed were not due to the direct effect of fluorine on the enamel, but to the interaction between fluorine and ameloblasts. The Authors have then carried out an ultrastructural study on the enamel organ using the S.E.M. The results showed the presence of a well-evident endoplasmic reticulum, the lack in dense granules during the secretion phase, the lack in ruffle ended webs during the modulation phase, and the mitochondrial damage in the ameloblast. All this could justify the slowing of the enamel mineralization caused by fluorine effect on the ameloblasts.