Papadopoulos Triantafillos, Papadogiannis Dimitris, Mouzakis Dionysios E, Giannadakis Konstantinos, Papanicolaou George
Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Greece.
Biomed Mater. 2010 Jun;5(3):35009. doi: 10.1088/1748-6041/5/3/035009. Epub 2010 May 27.
The aim of this study was to evaluate the mechanical behavior of endodontically treated teeth restored with fiber reinforced composite posts versus titanium posts, by both experimental testing and numerical simulation (finite element analysis (FEA)). Forty maxillary central incisors were endodontically treated to a size 45 file and then obturated using gutta-percha points and sealer with the lateral condensation technique. The teeth were divided into four groups of ten teeth each. All the posts were of similar dimensions. The first group was restored using carbon fiber reinforced posts (CB), the second and third groups were restored using glass fiber reinforced posts (DP and FW, respectively), and the fourth group (control group) was restored using conventional titanium posts (PP). Half of the specimens of every group were submitted to hydrothermal cycling (2000 cycles, at 5 °C and 55 °C, respectively). All specimens were loaded until failure at a 45° angle with respect to the longitudinal axis at a cross head speed of 0.5 mm min(-1). A two-dimensional finite element model was designed in order to simulate the experimentally obtained results. Mechanical testing revealed that teeth restored with titanium posts exhibited the highest fracture strength. Debonding of the core was the main failure mode observed in glass fiber posts, whereas vertical root fractures were observed in the titanium posts. FEA revealed that the maximum stresses were developed at the interface between the post, dentin and the composite core critical regions in all three cases. Hydrothermal cycling had no significant effect on the fracture behavior of fiber reinforced composite posts.
本研究的目的是通过实验测试和数值模拟（有限元分析（FEA））来评估用纤维增强复合桩与钛桩修复的根管治疗牙的力学行为。40颗上颌中切牙根管治疗至45号锉，然后采用牙胶尖和封闭剂通过侧向加压技术进行充填。将牙齿分为四组，每组十颗。所有桩的尺寸相似。第一组用碳纤维增强桩（CB）修复，第二组和第三组分别用玻璃纤维增强桩（DP和FW）修复，第四组（对照组）用传统钛桩（PP）修复。每组一半的标本进行热循环（2000次循环，分别在5℃和55℃）。所有标本以相对于纵轴45°角、十字头速度为0.5mm/min（-1）加载直至破坏。设计了二维有限元模型以模拟实验结果。力学测试表明，用钛桩修复的牙齿表现出最高的断裂强度。在玻璃纤维桩中观察到的主要失效模式是核的脱粘，而在钛桩中观察到垂直根折。有限元分析表明，在所有三种情况下，最大应力均出现在桩、牙本质和复合核临界区域之间的界面处。热循环对纤维增强复合桩的断裂行为没有显著影响。
