Fatigue and fracture behavior of radicular dentin substrate: prevention of tooth fracture

本研究的目的是比较神经根牙本质的疲劳强度和拉伸强度。沿根尖牙制作牙本质片，修剪成哑铃状标本。随后，进行了疲劳和拉伸试验。采用阶梯法确定疲劳强度及其标准差。平均疲劳强度和抗拉强度分别为44.3±5.0和84.4±8.3 Mpa。神经根牙本质的疲劳强度仅为抗拉强度的一半左右。此外，用扫描电子显微镜观察了断口。在工程材料中，疲劳破坏往往是通过循环裂纹扩展来实现的，这种循环裂纹扩展是由断口上一系列被称为“条纹”的自相似反射来识别的。我们证实神经根牙本质断裂面上的条纹间距大约在3到10μm之间。

The purpose of this study was to compare the fatigue and tensile strengths of radicular dentin. Dentin slabs were prepared along the radicular tooth and trimmed into dumbbell-shaped specimens. Subsequently, fatigue and tensile tests were performed. The staircase method was employed to determine fatigue strength and its standard deviation. Mean fatigue strength and tensile strength were 44.3 ± 5.0 and 84.4 ± 8.3 MPa, respectively. The fatigue strength of radicular dentin was only approximately one half of the tensile strength. Additionally, fracture surfaces were observed by scanning electron microscopy. In engineering materials, fatigue failures are often facilitated by cyclic crack extension, which is identified by a series of self-similar inflections on the fracture surface regarded as “striations”. We confirmed that striations spacing on fracture surfaces of radicular dentin ranged from approximately 3 to 10 μm.