Effect of fluoride and gonadal steroid deficiency on enamel and dentin mineralization of female rats.

The aim of this study was to verify the influence of estrogen deficiency on enamel and dentin microhardness of female rats' incisors, as well as the influence of chronic administration of fluoride on that response. Sham or OVX rats drank distilled water or distilled water with 10 ppm fluoride as NaF, for 90 days. The upper incisors were removed and the specimens submitted to microhardness analysis of enamel and dentin. The data were compared by variance analysis and Tukey's test (p<0.05). There was a significant reduction in the mineralization of crown (7.9% and 8.1%) and root (20.4% and 25.0%) in both groups treated with fluoride or distilled water, respectively and an increase (14.2%) in the mineralization of coronal dentin after ovariectomy. Fluoride treatment did not cause reduction in enamel mineralization; however, it reduced dentin mineralization following ovariectomy. It was possible to conclude that estrogens directly or indirectly influence the process of enamel and dentin mineralization of female rats' incisors. The results also indicate that enamel and dentin exhibit different responses to fluoride administration.