目的考察加速老化后光固化复合树脂的色度稳定性、表面显微结构和内部化学结构的改变及其相互之间的关系。方法用老化仪加速老化4种光固化复合树脂样本,测量老化24 h和96 h后的色差。用环境扫描电子显微镜和傅里叶变换红外光谱仪分别观察老化前后样本表面的显微结构和化学键的改变。用方差分析法分析老化时间与树脂色度间的交互影响(α=0.05)。结果老化时间与复合树脂类型之间具有交互作用(P<0.05),老化后复合树脂的色度改变具有统计学意义(P<0.05)。老化对复合树脂表面显微结构具有明显的影响,老化后基质出现凹陷,填料颗粒暴露,出现孔隙。老化使树脂内部化学键发生变化,基质中的化学键削弱和裂解,不饱和残余物再度聚合。结论随着老化时间的延长,复合树脂的色度变化加大;老化后混合型填料树脂的色度稳定性最好;老化使复合树脂内部化学键发生变化,色度发生改变。Objective The aim of this investigation was to examine the changes of the color stability,surface microstructure and chemical constitution of light-curing composite resin after accelerated aging,and the relations be-tween them.Methods Four light-curing composite resin were aged in an accelerated aging instrument.The color was measured by CIE L*a*b* with a spectrophotometer after treatment for 24 h and 96 h.And the color differences were calculated.Environmental scanning electron microscopy(ESEM) and Fourier transform infrared spectroscopy(FTIR) spectrometer were used to examine the microstructure and chemical composition of the specimens before and after accelerated aging.The color differences were analyzed statistically by repeated-measures two-way analysis of variance and t-test after aging for 24 h and 96 h.The level of significance was defined as α=0.05.Results The materials demonstrated statistically significant differences in color after aging between the 24 h and 96 h(P<0.05).There were significant influences on the microstructure and the chemical composition after aging.The matrix appeared some concaves and pores,the filler particles exposed after aging.The energy of chemical bonds were weaken or broken under the aging,and the unsaturated polymer reacted again.Conclusion The color differences of the composite resin increase with the aging time and irradiation dose.The hybrid filled composites have the best color stability
