牙本质小管平行和垂直方向上的牙本质力学性能研究

目的探讨人活髓牙本质在平行和垂直牙本质小管方向上的力学性能。方法收集30颗活髓牙,将其沿牙长轴制备成块状牙本质标本,分成2组。A组20个,标本长轴与牙本质小管垂直;B组10个,标本长轴与牙本质小管平行。采用位移测试法测试并比较其在平行或垂直于牙本质小管方向上的压缩力学性能。结果垂直于牙本质小管方向的牙本质弹性模量、比例极限、压缩强度分别为(16.03±1.35)GPa,(159.63±12.6)MPa,(258.59±10.39)MPa;平行于牙本质小管方向的牙本质弹性模量、比例极限、压缩强度分别为(15.26±1.78)GPa,(151.99±15.3)MPa,(255.48±10.35)MPa,两组结果经独立样本t检验差异无统计学意义(P>0.05)。结论牙本质的力学性能在平行和垂直牙本质小管方向上表现为各向同性。

Mechanical properties of dentin in different dentinal tubules direction

Objective To study the mechanical properties of human dentin obtained from vital teeth in different den- tinal tubules direction and analyze whether it is isotropic or anisotropic. Methods Dentin specimens were obtained from 30 freshly extracted nonnal vital human teeth and were grinded to be rectangular along the longitudinal axes of the teeth. Their compressive mechanical properties ahmg and perpendicular to the tubular orientation were measured with displace- ment measurement method. All data obtained were analyzed with t- tests. Results The elastic modulus, proportional limits and compressive strength of the longitudinal and transverse diIction of dentin were （ 16.03 ± 1.35） GPa and （15.26 ±1.78） GPa, （159.63 ±12.6） MPaand （151.99±15.3） MPa, （258.59 ±10.39） MPaand （255.48± 10.35 ） MPa respectively. There were no statistically significance between two directions with t-tests. Conclusion The compression mechanical properties of human dentin obtained from vital teeth are isotropic.