An immunohistochemical study of the effects of excessive fluoride on type I collagen in rat developmental dentine / 中华劳动卫生职业病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the effects of excessive fluoride on type I collagen in rat developmental dentine.</p><p><b>METHODS</b>Eighty SD rats, 5 days old, were divided into experimental and control groups, 40 in each group. The experimental group received subcutaneous injection of 0.2% NaF every 4 days (the dose was 2 mg NaF per kg body wt). The same volume of 0.9% NaCl was used in the control. Twenty rats in each group were killed 4 days after the second and the seventh injection respectively. The expression of type I collagen was assayed with immunohistochemical technique.</p><p><b>RESULTS</b>4 out of 20 rats after two injections showed abnormal distribution of type I collagen (dense stain of collagen in the odontoblast, aggregation of collagen in the dentine and disordered arrangement of collagen in the predentine; All 20 rats after seven injections showed abnormal distribution of type I collagen.</p><p><b>CONCLUSION</b>Excessive fluoride may affect the metabolism of type I collagen in rat developmental dentine.</p>