纳米羟基磷灰石和氢氧化钙对成牙本质细胞活性影响的比较

背景：将纳米羟基磷灰石与成牙本质细胞共同培养能更直观反映羟基磷灰石作为齿科盖髓材料的细胞相容性，但体外培养成牙本质细胞较困难。目的：观察纳米羟基磷灰石和氢氧化钙对小鼠成牙本质细胞的活性的影响。方法：取胎鼠下颌第一磨牙牙胚，采用组织块培养法对小鼠牙乳头细胞进行原代培养，倒置显微镜下挑选具有成牙本质样细胞形态的细胞观察细胞形态及生长情况。采用RT-PCR法对细胞牙本质涎磷蛋白的表达进行鉴定，确定为成牙本质样细胞。取对数生长期的第4代成牙本质样细胞，分别用含有100 mg/L纳米羟磷灰石和100 mg/L氢氧化钙的培养基培养1，3，5，7天，并设置空白对照组。 结果与结论：CCK-8法检测结果显示，培养1，3，5，7 d，纳米羟基磷灰石组的细胞生长良好。培养3，5，7 d，氢氧化钙组细胞活性低于空白对照组(P < 0.01)。碱性磷酸酶测定法检测结果显示，羟基磷灰石和氢氧化钙均对碱性磷酸酶活性无明显影响。结果证实，纳米羟基磷灰石对成牙本质细胞活性无影响，氢氧化钙对其细胞活性有抑制作用。

Comparison of the effects of nano-hydroxyapatite and calcium hydroxide on the cell activity of odontoblasts

BACKGROUND: Culturing odontoblasts with nano-hydroxyapatite can more intuitively reflect the biocompatibility of hydroxyapatite as dental pulp capping materials. However, odontoblasts are difficult to culture in vitro.OBJECTIVE: To observe the effect of nano-hydroxyapatite and calcium hydroxide on the cell activity of mouse odontoblasts.METHODS: Tooth germ of the first mandibular molar was took in fetal mice; mouse dental papilla cells were primary cultured using tissue block culture method. Cells with the cellular morphology of odontoblast-like shape were selected for the observation under inverted microscope. RT-PCR was used to detect the dentin sialophosphoprotein expression in order to identify the odontoblasts. Passage 4 odontoblasts in log-phase were cultured in the media containing 100 mg/L nano-hydroxyapatite and  100 mg/L calcium hydroxide respectively for 1, 3, 5 and 7 days. Blank control group was set up.RESULTS AND CONCLUSION: CCK-8 results showed that cells in the nano-hydroxyapatite group grew well on 1, 3, 5 and     7 days after culture. Cell activity in the calcium hydroxide group was lower than that in the blank control group on 3, 5 and 7 days after culture (P < 0.01). Alkaline phosphatase test results showed that nano-hydroxyapatite and calcium hydroxide had no obvious effect on the activity of alkaline phosphatase. These findings indicate that nano-hydroxyapatite has no effect on the activity of the odontoblasts, while calcium hydroxide has an inhibition effect on the activity of the odontoblasts.