Study on Mechanical Properties of Light Cured Composite Resins

本研究探讨了吸水性和热应力对两种不同类型的后牙复合树脂的化学固化和光固化体系的各种力学性能的影响，得到的结果如下：1)光固化和化学固化复合树脂的KC值相似，且随吸水率的增加而降低。2)水浸和热应力对两种材料的维氏硬度没有影响。3)通过扫描电镜观察，光固化和化学固化试样的断口形貌略有不同。随着处理时间的增加，大量的填料颗粒从两种复合树脂的表面脱落或突出。4)水吸附和热应力增强了表面粗糙度。此外，发现光固化复合材料比化学固化复合材料更粗糙。5)在压缩和三点弯曲载荷作用下，复合材料的声发射事件数随时间逐渐增加。

In this study, the influence of water sorption and thermal stress on various mechanical properties of two different types of posterior composite resins by chemically and light cured systems were investigated.The results obtained were summarized as follows. 1) Both light and chemical cured composite resins showed similar KC value and that decreased with the increase of water sorption. 2) Water immersion and thermal stress were not affected on Vickers hardness of both materials. 3) By SEM observation, fractured surfaces of light and chemically cured specimens were slightly different. With the time process increased, a remarkable number of filler particles was shown falling off or protruding from the surfaces of both composite resins. 4) Surface roughness was enhanced by water sorption and thermal stress. in addition, light cured composite was found to be rougher than chemically cured composite. 5) Under compressive and three-point-bending loading to the chemical composite resins, AE (Acoustic Emission) event counts were increased gradually with time.