[An immunohistochemical study of the effects of excessive fluoride on type I collagen in rat developmental dentine].
OBJECTIVE
To study the effects of excessive fluoride on type I collagen in rat developmental dentine.


METHODS
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.


RESULTS
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.


CONCLUSIONS
Excessive fluoride may affect the metabolism of type I collagen in rat developmental dentine.
Hao
Yu-qing
YQ
The College of Stomatology, Huaxi, Sichuan University, Chengdu 610041, China.
Wang
Gou-quan
GQ
Niu
Zhong-ying
ZY
Zhou
Xue-dong
XD
D000818:Animals; D000831:Animals, Newborn; D024042:Collagen Type I / Q000032:analysis*; D003804:Dentin / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development; D005459:Fluorides / Q000633:toxicity*; D007150:Immunohistochemistry; D051381:Rats; D017207:Rats, Sprague-Dawley
D024042:Collagen Type I; D005459:Fluorides