Matheus Tibério C U, Kauffman Cynthia M F, Braz Ana K S, Mota Cláudia C B O, Gomes Anderson S L
Department of Physics, Federal University of Pernambuco, Recife, PE, Brazil.
Braz Dent J. 2010;21(5):420-7. doi: 10.1590/s0103-64402010000500008.
This study used optical coherence tomography (OCT) compared to scanning electron microscopy (SEM) and optical microscopy (OM) to evaluate qualitatively crack propagation and final fracture in restorative composite materials - Filtek Z250 and Filtek Z350 (3M ESPE) - with fiber reinforcement after cyclic loading. Samples were made using a split mold. Initially, 3-point bending tests were performed to determine the maximum force and tension at the fracture moment using samples without fiber reinforcement. Then, mechanical cycling tests were performed using samples with glass fiber embedded internally. The failures were analyzed using the 3 methods described before. OCT permitted good characterization of internal crack propagation of the dental composites, which, however, could not be visualized by either SEM or OM. OCT was proven to be laboratory research tool that is easy to use, does not require any specific preparation of the samples, and is less expensive than SEM.
本研究使用光学相干断层扫描（OCT），并与扫描电子显微镜（SEM）和光学显微镜（OM）进行比较，以定性评估循环加载后含纤维增强的修复性复合材料——Filtek Z250和Filtek Z350（3M ESPE）中的裂纹扩展和最终断裂情况。样品采用分体模具制作。最初，使用未含纤维增强的样品进行三点弯曲试验，以确定断裂时刻的最大力和拉力。然后，使用内部嵌入玻璃纤维的样品进行机械循环试验。使用前述三种方法对失效情况进行分析。OCT能够很好地表征牙科复合材料的内部裂纹扩展情况，然而，SEM和OM均无法观察到这种情况。事实证明，OCT是一种易于使用的实验室研究工具，无需对样品进行任何特殊制备，且比SEM成本更低。
