三氧化矿物凝聚体对人乳牙牙髓细胞增殖和分化影响的实验研究

Effects of mineral trioxide aggregate and calcium hydroxide on the proliferation and differentiation capacity of pulp cells of primary teeth

目的对比三氧化矿物凝聚体（mineral trioxide aggregate，MTA）和氢氧化钙对人乳牙牙髓细胞增殖和分化的影响，为MTA应用于乳牙活髓保存治疗提供实验依据。方法培养原代人乳牙牙髓细胞，采用噻唑蓝比色法检测乳牙牙髓细胞生长增殖的变化；von Kossa染色观察牙髓细胞钙结节形成情况，并计数分析；使用实时荧光定量聚合酶链反应法检测碱性磷酸酶（alkaline phosphatase，ALP）、牙本质涎磷蛋白（dentin sialophosphoprotein，DSPP）基因的表达。结果氢氧化钙组牙髓细胞增殖率显著低于对照组和MTA组（F=1792．301，P〈0．01），最大增殖率为89．7％；MTA组牙髓细胞增殖率显著高于氢氧化钙组和对照组（F=1835．065，P〈0．01），最大增殖率为118．4％。氢氧化钙组和MTA组牙髓细胞von Kossa染色均呈阳性，两组间钙结节计数分析差异无统计学意义（P〉0．05）。三组间ALP基因表达量差异有统计学意义（F=349．651，P〈0．01），氢氧化钙组显著低于对照组和MTA组，MTA组显著高于氢氧化钙组和对照组；三组间DSPP基因表达量差异也有统计学意义（F=1653．001，P〈0．01），氢氧化钙组显著低于对照组和MTA组，MTA组显著高于氢氧化钙组和对照组。结论从促进乳牙牙髓细胞的增殖和分化来看，MTA比氢氧化钙更适合作为乳牙的盖髓剂。

Objective To investigate the effects of mineral trioxide aggregate （MTA） and calcium hydroxide on the proliferation and differentiation capacity of pulp cells of primary teeth. Methods Pulp cells were isolated from the retained primary teeth without apparent root resorption and cultured. The cells of 4-8 passages were used in the study. Cell proliferation was detected by MTT array, yon Kossa staining employed to observe the formation of mineralized nodules and mRNA expression of alkaline phosphatase （ALP） and dentin sialophosphoprotein （DSPP） determined by real time PCR. Results MTA-treated cells proliferated significantly faster than the other two groups （ F = 1835. 065, P 〈 0.01 ）, while calcium hydroxide-treated cells grew slower than the control significantly （F = 1792. 301, P 〈 0. 01 ）. The formation of mineralized nodules was found in both MTA-treated and calcium hydroxide-treated pulp cells. The number of mineralized nodules showed no significant difference between the two groups （ P 〉 0. 05 ）. Either ALP or DSPP mRNA expression showed significant difference among the three groups （ F = 349. 651, P 〈 0. 01 ; F = 1653.001, P 〈 0. 01 ）. MTA increased mRNA expression of ALP and DSPP in pulp cells （ P 〈 0.01 ） , whereas calcium hydroxide down-regulated them （ P 〈 0.01 ）. Conclusions MTA is more suitable than calcium hydroxide as pulp-capping agent in primary teeth.