摘要
目的 观察大鼠氟斑牙模型下颌切牙釉质的超微结构,探讨过量氟对牙体微观结构的影响.方法 30只5周龄SD大鼠雌雄各半,均分为3组,对照组用不含氟的去离子水喂养,低氟组用含22.5 mg/L F-（50 mg/L NaF）、高氟组用含45 mg/L F-（100 mg/L NaF）的去离子水喂养;饲养8周后,取所有大鼠下颌切牙,制备用于扫描电镜和原子力显微镜（atomic force microscopy,AFM）观察的牙体组织切片,分析比较不同氟浓度对大鼠釉质微观结构的影响.结果 扫描电镜结果显示,对照组样本釉质中釉柱结构完整,晶体排列紧密,层次清晰;高氟组样本釉柱结构瓦解,晶体松散、弯曲折断;低氟组样本釉柱结构形态的变化介于对照组与高氟组之间.AFM结果显示,对照组、低氟组及高氟组样本釉质中层的平均粗糙度分别为（550.6±32.0）、（415.0±24.2）及（194.3±11.3） nm,高氟组与对照组相比差异有统计学意义（P＜0.05）.结论 在高氟环境下形成的大鼠牙釉质出现明显的结构坍塌,釉柱间无间隙;高氟可造成大鼠发育中牙釉质的釉柱晶体正常结构丧失.
Objective To investigate the ultrastructure of enamel in the mandibular incisor tooth in a rat model of dental fluorosis.Methods Thirty 5-week-old male and female rats of SD strain were divided into three groups of ten.The animals in the control group were maintained for 8 weeks on pure deionized water,in the low-fluoride group deionized water with 22.5 mg/L of fluorine（50 mg/L NaF） was used,and in the high-fluoride group deionized water with 45 mg/L of fluorine（100 mg/L NaF） was used.All specimens examined were obtained from the mandibular incisors.Mid-sagittal ground sections were prepared from the direction of incisal point of each incisor for scanning electron microscopy（SEM） and atomic force microscopy （AFM）.Results According to the SEM results,the prisms in the control group had a complete and clear column structure with closely packed enamel rods or enamel prisms.The prisms in the high-fluoride experimental group were collapsed and showed curved and fractured crystallites.The level of prism structural changes in the low-fluoride experimental group was in between that of the control group and the high-fluoride group.AFM for the middle layer enamel showed an average roughness（Ra） of （550.6±32.0） nm in the control group,（415.0±24.2） nm in the low-fluoride group,and （194.3± 11.3） nm for the high-fluoride group.There was significant difference between the high-fluoride group and the control group（P〈0.05）.Conclusions Formation of rat enamel in the high fluoride environment presented obvious structural collapse and no clearance between prisms.Such changes appear to indicate a loss of normal prism structure in rat enamels from exposure to high levels of fluorine during the maturation period.
出处
《中华口腔医学杂志》
CAS
CSCD
北大核心
2015年第5期307-312,共6页
Chinese Journal of Stomatology
基金
国家自然科学基金
