Mair L H
Department of Clinical Dental Sciences, University of Liverpool, England, UK.
Dent Mater. 1994 Mar;10(2):111-5. doi: 10.1016/0109-5641(94)90050-7.
The purpose of this study was to evaluate subsurface fatigue in seven dental composites.
Cylindrical test pieces were subjected to 2000 compression cycles with a load of 120 N. The area of stained subsurface was measured, and subsequently, the specimens were examined by scanning electron microscopy.
The greatest staining occurred in the composites with large quartz fillers, whereas there was little staining in the microfilled materials. Electron microscopy demonstrated very little evidence of cracks, suggesting that silver nitrate stained a network of crazes and microcracks in the subsurface. The pattern of staining indicated that the microcracks formed within the depth of the subsurface rather than by direct nucleation from the indenter.
The different patterns of subsurface damage occurring as a result of compression should be considered when studying the wear and degradation of these materials.
本研究旨在评估七种牙科复合材料的亚表面疲劳情况。
将圆柱形试件在120 N的载荷下进行2000次压缩循环。测量亚表面染色区域，随后通过扫描电子显微镜检查试件。
含有大量石英填料的复合材料染色最严重，而微填料材料染色较少。电子显微镜显示几乎没有裂纹迹象，这表明硝酸银染出了亚表面的裂纹网络和微裂纹。染色模式表明微裂纹是在亚表面深度内形成的，而非由压痕直接形核产生。
在研究这些材料的磨损和降解时，应考虑压缩导致的不同亚表面损伤模式。
