人牙釉质及牙本质的纳米硬度与显微结构关系的研究

Relationship between the microstructure and nanohardness of dentin and enamel of human teeth

目的研究人牙釉质和牙本质的纳米硬度与显微组织的关系。方法利用纳米力学探针、透射电镜及红外光谱仪等设备分别对牙釉质和牙本质的纳米硬度及组织结构进行了测定。结果牙釉质的平均纳米硬度[（4．92±0．40）GPa]高于牙本质[（1．17±0．14）GPa]；结构分析显示，在牙釉质中存在大量晶格条纹均匀排列的羟基磷灰石晶体，而在牙本质中未观察到晶体结构。结论牙釉质与牙本质纳米硬度的差异同二者结构的致密度、无机物的形态及相结构有关。

Objective To investigate the relationship between the nanohardness and microstructure of the dentin and enamel of human teeth. Methods Nano indentation was used to determine the nanohardness of enamel and dentin; TEM and IR were utilized to observe the microstructure and crystalline characteristic. Results The mean nanohardness of the enamel [ （4.92 ± 0. 40 ） GPa ] was significantly higher than that of dentin [ （ 1.17 ± 0. 14） GPa]. A large quantity of hydroxyapatite （HA） crystals and uniform lattice stripe were found in enamel but not in dentin. Conclusions The difference of nanohardness between enamel and dentin is related to their density ,the inorganic morphology and phase structure.