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目的比较SD和Wistar两种品系大鼠在相同剂量和染氟时间下,对Na F诱导的氟斑牙易感度差异。方法选择断乳2周清洁级SD大鼠和Wistar大鼠各48只,按体重随机分为4组,每组12只,雌雄各半,分别为对照(自来水)组和50 mg/L(1/20 LD_(50))、150 mg/L(1/10 LD_(50))、250 mg/L(1/5 LD_(50))Na F染毒组。采用自由饮水方式进行染毒,连续染毒6个月。每月检测尿氟浓度并记录大鼠氟斑牙发生时间及程度;染毒结束后,检测大鼠骨氟和牙氟含量。结果各剂量Na F染毒组大鼠尿氟、骨氟和牙氟水平均高于同品系对照组,差异多有统计学意义(P<0.05);且随着Na F染毒剂量的升高和染毒时间的延长,SD和Wistar大鼠尿氟、骨氟和牙氟水平均呈上升趋势。与相同性别同剂量组Wistar大鼠比较,对照组和各剂量Na F染毒组SD大鼠不同染毒时间的尿氟浓度较高,骨氟和牙氟水平较低,差异多有统计学意义(P<0.05)。与Wistar大鼠比较,相同剂量Na F染毒组SD大鼠的氟斑牙出现较早,程度较重,检出率较高;染毒第5、6个月时,各剂量Na F染毒组两种品系大鼠均检出氟斑牙。结论 SD大鼠在体内氟负荷量较低的情况下出现比Wistar大鼠严重的氟斑牙病变,SD大鼠对氟斑牙易感性强于Wistar大鼠。
Objective To compare the susceptibility of dental fluorosis induced by NaF in SD rats and Wistar rats at the same dosage and time. Methods 48 weaned SD rats and Wistar rats were randomly divided into 4 groups according to body weight. Twelve male and female mice were randomly divided into control group (tap water group) and 50 mg / L / 50 LD50), 150 mg / L (1/10 LD_ (50)) and 250 mg / L NaF exposure group (1/5 LD_ (50)). Using free drinking water for exposure, continuous exposure for 6 months. The urinary fluoride concentration was detected every month and the time and degree of dental fluorosis were recorded. After the end of the exposure, the contents of fluoride and fluoride in bone were measured. Results The levels of urinary fluoride, bone fluoride and dental fluorosis in Na F group were significantly higher than those in the control group (P <0.05). With the increase of Na F dose And the extension of exposure time, urinary fluoride, bone fluoride and dental fluorosis in SD and Wistar rats all showed an increasing trend. Compared with the Wistar rats of the same sex and the same dose group, the urinary fluoride concentrations of the rats in the control group and those in the Na F group at different exposure times were higher, and the levels of bone fluoride and dental fluoride were lower, with statistically significant differences (P <0.05). Compared with Wistar rats, the rats with the same dose of NaF had higher incidence of dental fluorosis in SD rats, and the detection rate was higher. At the 5th and 6th month after exposure, NaF exposure Group two strains of rats were detected dental fluorosis. Conclusion SD rats have severe dental fluorosis lesions in Wistar rats with lower fluoride load in vivo. SD rats are more susceptible to dental fluorosis than Wistar rats.