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Ultrastructure and Crystallographic Study of Enamel in Human Dental Fluorosis.

人类氟斑牙牙釉质的超微结构和晶体学研究。

基本信息

批准号：
63440071
负责人：
MIAKE Yasuo
金额：
$ 18.3万
依托单位：
Tokyo Dental College
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

Materials used in this work were permanent molars of human and porcine dental fluorosis.Enamel surfaces from human subjects with dental fluorosis were generally cloudy to opaque, with several pits or defects of various size and degrees. Porcine subjects with dental fluorosis, however, were not seen pits or defects. Immediately below the relatively highly mineralized outermost surface enamel layer was an extensive hypomineralized area. The highly mineralized layer was composed of many large elongated hexagonal crystals and small hexagonal crystals. In some parts of the large crystals, crystal growth on the surface or attachment of extremely small crystals to the surface were observed. The lattice striations of the large and extremely small crystals were connected to each other in exact register. In views along the (100) plane, lattice intervals of large elongated hexagonal crystal were 0.817 nm. Shapes of small crystals were equilateral-hexagonal or nonequilateral-hexagonal and lattice … More intervals of it were 0.812 nm. This result showed that large elongated hexagonal crystals were hydroxyapatite and small crystals were fluorapatite. The hypomineralized enamel area was composed of fairly sparsely arranged, large crystals and a few small crystals. Large crystals were generally smaller than those observed in the surface layer. In some parts of this area, either the crystals large had perforations in their centers or irregular defects formed on their surfaces. Porcine subjects, however, were not seen those crystals. Both large and small crystal were observed in the transitional region between the highly mineralized surface layer and the subsurface hypomineralized area. Central perforations within the large crystals frequently contained apparently newly formed crystal fragments. Lattice striations between the original crystals and the newly formed crystalline material were not always in register with each other. Wave-dispersive electron-probe line analysis indicated that fluoride concentration was very high in the highly mineralized surface layer and low in the hypomineralized area. Less

这项工作中使用的材料是人类和猪氟斑牙的恒磨牙。患有氟斑牙的人类受试者的牙釉质表面通常是混浊到不透明的，有几个不同大小和程度的凹坑或缺陷。然而，患有氟斑牙的猪受试者却没有发现凹坑或缺陷。紧接着相对高度矿化的最外表面牙釉质层下方是大面积的低矿化区域。高度矿化层由许多大的细长六方晶体和小六方晶体组成。在大晶体的某些部分中，观察到晶体在表面上生长或极小的晶体附着在表面上。大晶体和极小晶体的晶格条纹精确地相互连接。从(100)面观察，大的细长六方晶体的晶格间距为0.817 nm。小晶体形状为等边六方或非等方六方，晶格间距为0.812 nm。该结果表明，大的细长六方晶体是羟基磷灰石，小晶体是氟磷灰石。矿化不足的牙釉质区域由排列相当稀疏的大晶体和一些小晶体组成。大晶体通常比在表层中观察到的晶体小。在该区域的某些部分，大晶体要么在其中心有穿孔，要么在其表面形成不规则的缺陷。然而，猪受试者没有看到这些晶体。在高度矿化的表层和地下低矿化区域之间的过渡区域中观察到了大晶体和小晶体。大晶体内的中心穿孔经常含有明显新形成的晶体碎片。原始晶体和新形成的晶体材料之间的晶格条纹并不总是彼此对齐。波色散电子探针线分析表明，高矿化表层氟化物浓度非常高，而低矿化区域氟化物浓度较低。较少的