Sano H, Ciucchi B, Matthews W G, Pashley D H
Department of Operative Dentistry, Tokyo Medical and Dental University, Japan.
J Dent Res. 1994 Jun;73(6):1205-11. doi: 10.1177/00220345940730061201.
The relative contribution of the matrix of dentin to the physical properties of dentin is unknown but thought to be small. The objective of this study was to test the hypothesis that the demineralized matrix of dentin contributes little to the strength of dentin by measuring and comparing the ultimate tensile strength and modulus of elasticity of mineralized and demineralized dentin. Small slabs (4 x 0.5 x 0.5 mm) of bovine and human dentin were tested in a microtensile testing device in vitro. Human coronal mineralized dentin gave a mean ultimate tensile strength (UTS) of 104 MPa. Bovine incisor coronal dentin exhibited a UTS of 91 MPa, and bovine root dentin failed at 129 MPa. The modulus of elasticity of mineralized bovine and human dentin varied from 13 to 15 MPa. When dentin specimens were demineralized in EDTA, the UTS and modulus of elasticity fell to 26-32 MPa and 0.25 GPa, respectively, depending on dentin species. The results indicate that collagen contributes about 30% of the UTS of mineralized dentin, which is higher than was expected.
牙本质基质对牙本质物理特性的相对贡献尚不清楚，但据认为很小。本研究的目的是通过测量和比较矿化牙本质与脱矿牙本质的极限拉伸强度和弹性模量，来检验牙本质脱矿基质对牙本质强度贡献不大这一假设。在体外微拉伸测试装置中对牛和人牙本质的小薄片（4×0.5×0.5毫米）进行测试。人冠状矿化牙本质的平均极限拉伸强度（UTS）为104兆帕。牛切牙冠状牙本质的UTS为91兆帕，牛牙根牙本质在129兆帕时失效。矿化牛和人牙本质的弹性模量在13至15兆帕之间变化。当牙本质标本在乙二胺四乙酸（EDTA）中脱矿时，根据牙本质种类，UTS和弹性模量分别降至26 - 32兆帕和0.25吉帕。结果表明，胶原蛋白对矿化牙本质UTS的贡献约为30%，高于预期。
