Fatigue analysis of restored teeth longitudinally cracked under cyclic loading.
Fatigue analysis of restored teeth longitudinally cracked under cyclic loading.
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DOI：
10.1016/j.dental.2021.12.005
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发表时间：
2022-01
期刊：
影响因子：
--
通讯作者：
Fok ASL
中科院分区：
文献类型：
--
作者：
Lin F;Ordinola-Zapata R;Ye N;Xu H;Fok ASL
采用有限元分析（FEA）和应力-寿命（S-N）方法研究修复牙的疲劳行为，特别是在循环机械载荷下牙本质纵向开裂的机制。对10颗树脂基复合材料修复的根管充填前磨牙进行阶跃应力循环加载，产生纵向裂纹。记录断裂载荷和在每个载荷水平下完成的循环次数。有限元分析用于预测每个部件在全局循环载荷下的应力幅。在有限元分析中，牙本质-复合材料界面被认为是完整的和脱粘的条件。预测的应力集中与断裂模式进行了比较，以帮助阐明故障机制。S-N方法进一步用于预测修复牙齿中不同成分的寿命。累积疲劳损伤用不同应力幅下寿命分数之和表示。在约50%的样本中观察到纵向裂纹，平均断裂载荷为770±45 N，平均失效循环次数为32297±12624。牙本质纵裂起始于牙洞线角附近，并向牙根方向扩展。牙本质-复合材料界面的寿命分数之和在约7000次循环后超过1，而牙本质的寿命分数之和远低于1，表明界面脱粘发生在牙本质断裂之前。这是支持微CT图像显示在开裂的样品中的界面空间变宽。在脱粘牙中，有限元分析显示牙本质应力集中在洞的牙龈壁，这与在循环载荷试验中发现的纵向裂纹相吻合。牙本质寿命分数之和在~30000次循环时接近1，与实验值相似。在循环载荷作用下，根充牙本质-复合材料界面的脱粘可能先于牙本质纵向开裂发生。这些事件发生的大致时间可使用FEA提供的应力疲劳分析进行估计。因此，该方法可用于评估根充牙修复设计的寿命。
To investigate the fatigue behavior of restored teeth, in particular the mechanisms of longitudinal dentinal cracking under cyclic mechanical loading, using finite element analysis (FEA) and the stress-life (S-N) approach. Ten root-filled premolars restored with resin composites were subjected to step-stress cyclic loading to produce longitudinal cracks. Fracture loads and number of cycles completed at each load level were recorded. FEA was used to predict the stress amplitude of each component under the global cyclic load. Both intact and debonded conditions were considered for the dentin-composite interface in the FEA. The predicted stress concentrations were compared with the fracture patterns to help elucidate the failure mechanisms. The S-N approach was further used to predict the lifetimes of the different components in the restored teeth. Cumulative fatigue damage was represented by the sum of the fractions of life spent under the different stress amplitudes. Longitudinal cracks were seen in ~50% of the samples with a mean fracture load of 770±45 N and a mean number of cycles to failure of 32297±12624. The longitudinal dentinal cracks seemed to start near the line angle of the cavity, and propagated longitudinally towards the root. The sum of fractions of life spent for the dentin-composite interface exceeded 1 after ~7000 cycles when that for dentin was much lower than 1, indicating that interfacial debonding would occur prior to dentin fracture. This was supported by micro-CT images showing widened interfacial space in the cracked samples. In the debonded tooth, FEA showed dentinal stress concentrations at the gingival wall of the cavity, which coincided with the longitudinal cracks found in the cyclic loading test. The sum of fractions of life spent for dentin was close to 1 at ~30000 cycles, similar to the experimental value. Debonding of the dentin-composite interface may occur prior to longitudinal cracking of dentin in root-filled teeth under cyclic loading. The approximate time of occurrence for these events could be estimated using fatigue analysis with stresses provided by FEA. This methodology can therefore be used to evaluate the longevity of restoration designs for root-filled teeth.
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DOI：
10.1111/j.1708-8240.2010.00330.x
发表时间：
2010-06
期刊：
Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.]
影响因子：
--
作者：
Lubisich EB;Hilton TJ;Ferracane J;Northwest Precedent
通讯作者：
Northwest Precedent
影响因子：
5
作者：
Li, Yuping;Carrera, Carola;Chen, Ruoqiong;Li, Jianying;Chen, Yungchung;Lenton, Patricia;Rudney, Joel. D.;Jones, Robert S.;Aparicio, Conrado;Fok, Alex
通讯作者：
Fok, Alex
影响因子：
5
作者：
Aregawi, Wondwosen A.;Fok, Alex S. L.
通讯作者：
Fok, Alex S. L.
影响因子：
5
作者：
Lin F;Ordinola-Zapata R;Xu H;Heo YC;Fok A
通讯作者：
Fok A
影响因子：
5
作者：
Arola, Dwayne
通讯作者：
Arola, Dwayne