University of Perugia, Civil and Environmental Engineering Department, UdR INSTM, Strada di Pentima, 4, - 05100 Terni, Italy.
University of Perugia, School of Medicine, Department of Biomedical and Surgical Sciences, Odontostomatological University Centre, S. Andrea delle Fratte, 06156 Perugia, Italy.
Mater Sci Eng C Mater Biol Appl. 2017 May 1;74:334-346. doi: 10.1016/j.msec.2016.12.022. Epub 2016 Dec 7.
The aim of this work was to evaluate the stress distribution inside endodontically treated teeth restored with different posts (glass fibre, carbon fibre and steel posts) under different loading conditions by using a 3D-finite element analysis. The effect of masticatory and impact forces on teeth with different degrees of bone loss was analysed. The model consists of: dentine, post, cement, gutta-percha, core and crown. Four simulations were conducted with two static forces (170N horizontal and 100N oblique) and two sections constrained: 1mm (alveolar bone position in a normal periodontium) and 6mm (middle of root) below the crown. Von Mises and the principal stresses were evaluated and analysed with a 3-way ANOVA and Tukey test (α=0.05) and the effect of fibre percentage analysed. Significant differences were found among the stress values for all conditions (p<0.05). Impact load was always responsible for the most critical situation especially when the bone loss was more evident. The system with steel posts showed the highest principal stresses at the post-cement interface with horizontal load and top constraints (compressive stress of 121MPa and tensile stress of 115MPa). The use of glass posts provides a more homogeneous behaviour of the system with lower stresses. Higher fibre percentages gave higher stress in the posts. Moreover, larger bone losses are responsible for important increase in stress. Thus, this work demonstrated that periodontal disease has an important role in the success of tooth restoration after endodontic therapy, influencing the choice of post material and depth.
本研究旨在通过三维有限元分析，评估不同类型（玻璃纤维、碳纤维和金属）桩核系统在不同加载条件下的根管治疗牙的内部应力分布，分析咀嚼和撞击力对不同程度牙槽骨吸收的牙体的影响。模型包括牙本质、桩、黏固剂、牙胶、核和牙冠。共进行了 4 种模拟，施加了两种静态力（170N 水平和 100N 斜向）和两种节段约束：牙冠下 1mm（正常牙周牙槽骨位置）和 6mm（根中部）。评估和分析了 Von Mises 和主应力，并采用三因素方差分析和 Tukey 检验（α=0.05）分析纤维百分比的影响。所有条件下的应力值均存在显著差异（p<0.05）。冲击载荷总是导致最关键的情况，尤其是当骨吸收更明显时。在水平载荷和顶部约束下，金属桩系统的桩-黏固剂界面处显示出最高的主应力（压缩应力为 121MPa，拉伸应力为 115MPa）。玻璃纤维桩的使用提供了更均匀的系统行为，应力较低。较高的纤维百分比会导致桩内的应力增加。此外，较大的骨损失会导致应力的显著增加。因此，本研究表明，牙周病在根管治疗后牙修复的成功中起着重要作用，影响着桩材料和深度的选择。
