44 Ca doped remineralization study on dentin by isotope microscopy
44 Ca doped remineralization study on dentin by isotope microscopy
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同位素显微镜下44 Ca掺杂牙本质再矿化研究
DOI：
10.1016/j.dental.2018.01.022
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发表时间：
2018
期刊：
影响因子：
5
通讯作者：
Tagami J.
中科院分区：
文献类型：
--
作者：
Hiraishi N.;Kobayashi S.;Yurimoto H.;Tagami J.
龋齿是由于矿物质的获得和损失的替代过程而发展的。为了区分内源性钙（牙源性矿物质）和外源性钙（溶液源性矿物质）的摄取，用44 Ca（一种稳定的钙同位素）矿化溶液进行44 Ca掺杂的pH循环。使用44 Ca制备的矿化溶液含有1.5 mmol/L CaCl 2（44 Ca）、0.9 mmol/L KH 2 PO 4、130 mmol/L KCl、20 mmol/L HEPES（pH 7.0）。牛牙根牙本质每天进行pH循环，脱矿（pH 5.0）2 h，在0%（对照）和0.2%NaF（900 ppm氟化物）中孵育2 h，44 Ca掺杂矿化20 h。在14天的pH循环后，将样本纵向切片。在切片表面，同位素成像的40 Ca和44 Ca标记的矿物分布观察到的高质量分辨率的二次离子77（相机IMS 1270，Gennevilliers Cedex，法国）。结果摄取的44 Ca是更大的强度为0.2%的氟化物组比对照组，特别是在浅表病变。对照组40 Ca在病灶内分布于病灶的亚表面和浅表，而氟组40 Ca分布局限于病灶的亚表面。由于氟化物处理的牙本质表面比固有牙本质更耐酸，因此在脱矿循环中，替代矿物从完整的固有损伤中溶解。
ObjectiveThe dental caries is developed as a result of an alternative course of mineral gain and loss. In order to distinguish between intrinsic Ca (tooth-derived mineral) and extrinsic Ca (solution-derived mineral) uptakes, a44Ca doped pH-cycling was performed using44Ca (a stable calcium isotope) remineralization solution.MethodsThe natural abundance of40Ca and44Ca is 96.9% and 2.1%, respectively. The remineralization solution was prepared using44Ca to contain 1.5 mmol/L CaCl2(44Ca), 0.9 mmol/L KH2PO4,130 mmol/L KCl, 20 mmol/L HEPES at pH 7.0. The pH-cycling was conducted on bovine root dentin daily by demineralization (pH 5.0) for 2 h, incubation in 0% (control) and 0.2% NaF (900 ppm fluoride) for 2 h and44Ca doped remineralization for 20 h. After 14 days pH-cycling, the specimens were sectioned longitudinally. On the sectioned surface, isotope imaging of40Ca and44Ca labeled mineral distribution was observed by a high mass-resolution stigmatic secondary ion 77 (Camera IMS 1270, Gennevilliers Cedex, France).ResultsUptake of44Ca was greater in intensity for the 0.2% fluoride group than the control, especially in the superficial lesions. The control group showed40Ca (intrinsic) distribution in the subsurface lesions and in the superficial lesions, meanwhile the fluoride group showed40Ca distribution limited in subsurface lesions. The total Ca (44Ca +40Ca) image revealed more homogeneously for the control than the fluoride group.SignificanceSince the fluoride-treated surface is more acid-resistant than intrinsic dentin, alternative minerals were dissolved from the intact intrinsic lesion in the demineralization cycle.