De Groot R, Van Elst H C, Peters M C
Department of Cardiology and Endodontology, School of Dentistry, University of Nijmegen, The Netherlands.
J Dent Res. 1988 Jun;67(6):919-24. doi: 10.1177/00220345880670060601.
This study contains the first part of a research project in which the applicability of fracture mechanics parameters to predict failure of a restored tooth was investigated. Fracture mechanics parameters have been used in dental research before, but were restricted to comparative studies between various brands of composites. The critical values of the opening mode stress intensity factor (KI), its equivalents, the strain energy release rate (GI), and the J integral (JI), were measured with single-edge notched-bend (SENB) specimens of dental composite in a three-point bend test. The measured values of KIc for Silux (KIc = 0.99 +/- 0.03 MNm-3/2) and P-30 (KIc = 1.88 +/- 0.12 MNm-3/2), compared with values from the literature, show quantitative agreement. The J integral was computed by means of finite element analysis (FEA) on a two-dimensional model of the SENB specimens. The critical value of the J integral (measured with SENB specimens, notch depth-to-width ratio (a/W) = 1/2) was used to predict failure of specimens having an arbitrary geometry. In this study, failure was predicted for SENB specimens with notch depth-to-width ratio (a/W) = 1/4 and 3/4. The predicted deflection and load at failure correspond well with the measured deflection and load.
本研究包含一个研究项目的第一部分，该项目调查了断裂力学参数预测修复后牙齿失效的适用性。断裂力学参数此前已用于牙科研究，但仅限于不同品牌复合材料之间的比较研究。在三点弯曲试验中，使用牙科复合材料的单边切口弯曲（SENB）试样测量了开口模式应力强度因子（KI）及其等效参数应变能释放率（GI）和J积分（JI）的临界值。Silux（KIc = 0.99 +/- 0.03 MNm-3/2）和P - 30（KIc = 1.88 +/- 0.12 MNm-3/2）的KIc测量值与文献中的值相比，显示出定量一致性。通过对SENB试样的二维模型进行有限元分析（FEA）来计算J积分。J积分的临界值（用SENB试样测量，缺口深度与宽度比（a/W）= 1/2）用于预测具有任意几何形状的试样的失效。在本研究中，预测了缺口深度与宽度比（a/W）= 1/4和3/4的SENB试样的失效情况。预测的失效挠度和载荷与测量的挠度和载荷吻合良好。
