不同金属基底和遮色瓷厚度对金瓷修复体色彩的影响

目的　对比不同金属基底和遮色瓷厚度对金瓷修复体色彩的影响,力求找出能有效遮住底层冠金属色的最佳遮色瓷厚度。方法　制作贵金属合金、金沉积与镍铬合金片,分别以其为基底依次制作遮色瓷厚度为0·05、0·1、0·2、0·3、0·4、0·5 mm的试件。用CR-321色差计对试件测色,计算色差并进行统计分析。结果　以镍铬合金与贵金属合金为基底的瓷修复体遮色瓷厚度为0·3 mm时可以完全遮住底色,色差值小于1·5 NBS;金沉积为基底的修复体遮色瓷厚度为0·1 mm即可完全遮住底色,色差值小于1·5 NBS。结论　对于不同的金属基底材料,有不同的遮色瓷厚度要求;随遮色瓷厚度的增加,以镍铬合金与贵金属合金为基底的修复体彩度增加,金沉积为基底的修复体彩度略有下降。

Effects of Varying the Opaque Thickness and the Type of Metal Ceramic Alloy on Color

OBJECTIVE: To compare the color differences of different metal bases and different opaque thickness, and evaluate the best thickness of opaque on different metal bases. METHODS: Precious metal, gold sediment and Ni-Cr plates were prepared as bases, then opaque samples of 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5 mm thickness were fabricated on such plates. Minolta chromatics meter CR-321 was used to examine the color properties of these samples, and deltaE was calculated to evaluate the color difference of the specimens. RESULTS: For the restoration based on Ni-Cr and precious alloys, the color of restorations was not affected by the color of metal bases as the thickness of opaque reached 0.3 mm, and the chromatic value deltaE < 1.5 NBS. For the restoration based on gold sediment, the color of restoration was not affected by the color of metal as the thickness of opaque reached 0.1 mm, and the chromatic value deltaE < 1.5 NBS. CONCLUSION: Different opaque thickness was necessary to obtain ideal color appearance in clinic. As the opaque thickness increased, the color of restoration based on Ni-Cr and noble metal increased but the color of restoration based on gold sediment decreased.