着色介质及表面粗糙度对热固化基托树脂着色的影响

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。

Effects of coloring agents and surface roughness on the coloring of heat-cured base resin

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 △E(P<0.05).Conclusion:Extrinsic pigment may stain heat-cured base resin,the rough surface can increase the staining susceptibility.