关键词: 氟, 大鼠, 氟斑牙

Abstract: Objective To set up the animal model of dental fluorosis in the lower incisors in Sprague-Dawley(SD)rats and investigate the changes of enamel surface color and amoblogine in rat incisor exposed to fluoride.Methods 105 male SD rats,average weight 200 g,were randomly divided into four groups.15 rats were with distilled water(control group).The other three group SD rats were rendered fluorotic by the administration of 25 mg/L,50 mg/L,100 mg/L sodium fluoride in their drinking water ad libitum.At the different time sites of 5,10,20,30,42 day,every rat was taken a photo of labial enamel surface of the lower incisor.Then some of the rats were sacrificed,manbibular incisors were removed,fixed,demineralized and sections prepared for H-E staining for light-microscopic morphometric observation.Results The normal color of enamel in rat incisor was yellow/yellow-orange.In this test,the fluorosis model was established successfully in incisors at 50 mg/L and 100 mg/L sodium fluoride groups.The enamel color in incisors were present white-chalk,straition and pitting,the ameloblasts arranged in multiple layers.The apperences of enamel fluorosis were ealier and more severity in 100 mg/L than 50 mg/L sodium fluoride group.The normal incisor color and the normal morphology of the ameloblasts were in the control group and the experimental group 25 mg/L NaF.Conclusion 50 mg/L or 100 mg/L NaF may reduced the dental fluorosis successfully in continuous growth incisors in SD rats.the enamel surface in fluorosed rats exhibited opacity,white-chalk,and discoloration of varying extent.No obvious changes in ameloblasts and enamel surface apperenced in control group and 25 mg/L NaF group.

Key words: Fluoride, Rat, Dental fluorosis