On the stiffness of demineralized dentin matrices.
On the stiffness of demineralized dentin matrices.
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DOI：
10.1016/j.dental.2015.11.029
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发表时间：
2016-02
期刊：
影响因子：
--
通讯作者：
Arola D
中科院分区：
文献类型：
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作者：
Ryou H;Turco G;Breschi L;Tay FR;Pashley DH;Arola D
树脂与牙本质的结合需要使用自蚀刻底漆或酸蚀刻来脱钙表面并暴露一层牙本质基质的胶原原纤维。酸蚀可以将脱矿牙本质的硬度从大约19 GPa降低到1 MPa，这需要它漂浮在水中，以防止它在粘合过程中坍塌。一些出版物表明，交联剂如麸醛、碳二亚胺或葡萄籽提取物可以硬化胶原蛋白，提高树脂-牙本质的结合强度。目的是评估极性溶剂和胶原交联剂对脱钙牙本质硬度变化的新方法。在用乙醇或乙基-3-（3-二甲氨基丙基）碳二亚胺（EDC）处理后，用圆柱扁平压痕器在水中对完全脱矿的牙本质梁和蚀刻的冠状牙本质切片进行压痕加载。刚度作为应变的函数和加载速率从1到50µm/sec的函数进行测量。当应变为0.25%时，完全脱矿牙本质的弹性模量约为0.20 MPa。在1%的应变下，其强度增加到0.90 MPa以上。暴露于乙醇引起的弹性模量的增加可达四倍。将加载速率从1µm/sec增加到50µm/sec，在水和乙醇中的表观模量都增加了3倍。EDC处理导致完全脱矿样品和酸蚀脱矿牙本质原位表面的刚度增加。在脱矿胶原基质的力学行为的变化可以有效地测量水合作用下通过压痕与圆柱形扁平压痕。该方法可用于量化酸蚀后键合处理对脱钙牙本质性能的影响，以及跟踪由于酶降解而导致的硬度随时间的损失。
Resin bonding to dentin requires the use of self-etching primers or acid etching to decalcify the surface and expose a layer of collagen fibrils of the dentin matrix. Acid-etching reduces the stiffness of demineralized dentin from approximately 19 GPa to 1 MPa, requiring that it floats in water to prevent it from collapsing during bonding procedures. Several publications show that crosslinking agents like gluteraladehyde, carbodiimide or grape seed extract can stiffen collagen and improve resin-dentin bond strength. The objective was to assess a new approach for evaluating the changes in stiffness of decalcified dentin by polar solvents and a collagen cross-linker. Fully demineralized dentin beams and sections of etched coronal dentin were subjected to indentation loading using a cylindrical flat indenter in water, and after treatment with ethanol or ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The stiffness was measured as a function of strain and as a function of loading rate from 1 to 50 µm/sec. At a strain of 0.25% the elastic modulus of the fully demineralized dentin was approximately 0.20 MPa. It increased to over 0.90 MPa at strains of 1%. Exposure to ethanol caused an increase in elastic modulus of up to four times. Increasing the loading rate from 1 to 50 µm/sec caused an increase in the apparent modulus of up to three times in both water and ethanol. EDC treatment caused increases in the stiffness in fully demineralized samples and in acid-etched demineralized dentin surfaces in situ. Changes in the mechanical behavior of demineralized collagen matrices can be measured effectively under hydration via indentation with cylindrical flat indenters. This approach can be used for quantifying the effects of bonding treatments on the properties of decalcified dentin after acid etching, as well as to follow the loss of stiffness over time due to enzymatic degradation.