数码摄影比色法探究三种临时冠材料颜色稳定性

Color stability of three provisional restorative resins measured by photographic system

目的探究比较常用三种临时冠材料的颜色稳定性,为临床医师提供参考。方法选取一种主要成分为Poly(methyl methacrylate)(PMMA)的自凝塑料,两种主要成分为Bis-acryl的复合树脂Protemp和Luxatemp。制备标准试件,分别浸泡于5种浸泡液中不同时间。用数码相机于浸泡前后拍照记录颜色。数据上传至Photoshop软件中读取试件L~*,a~*,b~*值,根据色差公式计算色差△E。结果除人工唾液方案外,三种材料在不同浸泡液中的色差均随时间增加而增大。人工唾液色差平均值△E与其他各浸泡液的色差平均值△E有显著差异(P<0.05)。14天后每组中最大色差△E分别出现在Protemp(唾液+红酒方案)>Luxatemp(唾液+红酒方案)>PMMA组(唾液+咖啡方案),结果具有统计学意义(P<0.05)。结论时间是使临时冠树脂材料产生颜色改变的重要因素。PMMA临时冠材料的颜色稳定性优于Bis-acryl。

Objective The aim of this in vitro study was to measure the color stability of three provisional prosthodontic materials. Methods Three provisional crown and bridge resins were selected. One was made of poly（methyl methacrylate）（PMMA）and two were made of bis-acrylic composite（Protemp and Luxatemp）. The specimens of the three resins were immersed in artificial saliva（as）, as ＋ tea, as ＋ coffee, as ＋ red wine, and as ＋ cola for 3 days, 7 days and 14 days. A digital camera was used to record the color of the specimens with the same parameters and camera settings before and after the immersion. The images were uploaded into Photoshop and the L^＊, a^＊, b^＊ values of the specimens were recorded. Color changes（△E）between baseline and each storage interval were then calculated. Results As the duration of immersion increased, the color change values of all the materials increased in all the staining solutions except for artificial saliva solution. Independent t-test showed statistically significant difference when comparing specimens immersed in artificial saliva with specimens immersed in various staining solutions in both the groups after 3, 7 and 14 days（P〈0.05）. The biggest color change observed in each group was Protemp（as ＋wine）〉Luxatemp（as ＋ wine）〉PMMA（as ＋ coffee）, P〈0.05. Conclusion Time was an important factor in the staining of provisional crown and bridge resins. Tea, coffee, wine and cola could change the color of resins in an unacceptable way after a certain period of time. PMMA was more color stable than Bis-acryl.