Effects of overdosed fluoride on rat's incisor expression of matrixmetalloproteinase-20 and tissue inhibitors of metalloproteinase-2 / 华西口腔医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effects of overdosed fluoride on the expression of MMP-20 and TIMP-2 in rat incisor.</p><p><b>METHODS</b>20 Wistar rats were randomly divided into experiment group and control group. The distilled water was given in control group. 100 mg/L fluoride- was given in experiment group. After 8 weeks treatment, the rats were killed. Immunohistochemical staining was used to observe the expression of MMP-20 and TIMP-2 in rat incisors.</p><p><b>RESULTS</b>Immunohistochemical results demonstrated the presence of MMP-20 and TIMP-2 protein in ameloblasts, odontoblasts, stratum intermedium and the stellate reticulum of rat incisor. The imagination analysis results showed that the expression of MMP-20 was reduesed in experiment group (P<0.01), and the expression of TIMP-2 had no significant difference (P>0.05).</p><p><b>CONCLUSION</b>The overdosed fluoride inhibits the secretion of MMP-20 and leads to the disturbed balance between MMP-20, TIMP-2 in rat incisor, which leads to the delay of the amelogenin removal and the enamel demineralization.</p>