染色烧结次数对CAD-CAM全瓷半透明性和颜色的影响

Effect of stain firing on the translucency and the color of all-ceramic CAD/CAM restorations

目的研究染色烧结次数对CAD-CAM全瓷半透明性和颜色的影响。方法测量5次染色烧结前后CAD-CAM瓷块的透光率和颜色。采用1931CIE-XYZ表色系和CIE1976Lab标准色度系统,计算透光率CR,色差△Eab,彩度Cab,色相角hab。结果随机区组设计方差分析,染色烧结次数达到4次时,A1C、A3C瓷块的半透明性均有显著性改变。烧结后瓷块颜色发生改变,明度和彩度均变大,但与烧结次数无关。A1C色瓷色差大于1.4,色相角随着烧结次数的增加而增加;A3C色瓷色差小于1.4,色相角无明显改变。结论CAD-CAM全瓷染色烧结对A1C和A3C全瓷块半透明性有影响。染色烧结可以改变瓷块的颜色,但与烧结次数无关。

Objective ：To investigate the influence of repeated stain firing on the translucency and the color of all-ceramic CAD/CAM restorations. Methods：16 all-ceramic sample disks, including 8 of A1C and 8 of A3C in the size of 15 mm × 10 mm × 1 mm were fabricated and fired for 5 times. Color was measured before and after stain firing using a colorimeter. Translucency was evaluated by determining the contrast ratio（ CR）, and changes in color were evaluated by determining color difference △E^＊ ab, hue angle hab^＊ , chroma Cab and brightness L^＊. Results： The translucency of A3C was greater than that of A1C. More than 4 time firing increased CR value of both A1C and A3C samples（P 〈 0.05 or P 〈 0.01 ）. △ E^＊ ab of more than 1.4, a visually appreciable change, was found in A1C specimens after firing and there was no detectable clinically relevant differences in A3C specimens. After stain firing, L^＊ and Cab values of all samples increased, the hab^ ＊ of A1C samples increased. Conclusion ：The transIucency and the color of CAD/CAM all-ceramic restorations changes after stain firing, the change of color is not related to the times of firing.