Objective:To study the staining of heat-cured base resin with different surface roughness by different coloring agents. Methods; 64 specimens ( 20 mm×20 mm×5 mm) made of heat- cured base resin were divided into 4 groups ( n = 16 ) and then different surface roughness degree were produced for different groups. A surface roughness tester was used to measure Ra along 3 tracks on each surface. The specimens in the 4 groups were immersed in coffee, tea, vinegar and water( n= 4 for each coloring agent) respectively and treated for 4 weeks. The initial and further color values of each specimen were measured using a colorimeter. The CIE L * a * b* values were recorded and color differences (△E) after staining were calculated. Data were statistically analyzed using analysis of variance ( ANOVA). Results; The △E of the specimens in coffee and tea was significantly affected by the immersion solutions (P < 0. 05 ) , and the higher( △E) was observed in the samples treated by coffee than by tea( P < 0. 05). There were no statistically evidence of color change in water and in vinegar( P >0. 05). The specimens with greater surface roughness demonstrated the higher AE(P< 0.05). Conclusion;Extrinsic pigment may stain heat-cured base resin, the rough surface can increase the staining susceptibility.%目的:研究4种着色介质对不同表面粗糙度的热固化基托树脂的表面着色状况.方法:制作64个热固化基托树脂试件,随机分成4组,不同组试件的测试面打磨出不同的粗糙度等级,用表面粗糙度轮廓仪测量其表面粗糙度参数Ra并记录,然后将每组试件分别浸泡于蒸馏水(对照)、咖啡、茶和陈醋中,用分光光度比色仪测量试件浸泡前及浸泡4周后的颜色,得到L*、a *、b*值,计算浸泡前后的色差△E,采用统计学方法,分析热固化基托树脂着色与上述因素的关系.结果:除对照组外,咖啡组和茶组试件的色差值△E均增大(P＜0.05),且咖啡组的△E大于茶组(P＜0.05),陈醋组的△E无明显改变(P＞0.05)；同一浸泡液中不同表面粗糙度的试件的△E值差异有显著性(P＜0.05),表面粗糙度越大,△E越大.结论:外源性色素能引起基托树脂的着色,并且树脂表面越粗糙,着色越明显.
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