烧结次数对计算机辅助设计制作渗透铝瓷-饰面瓷复合材料颜色稳定性的影响

Effect of repeated firings on the color stability of dental computer aided design/computer aided manufacture infiltration alumina core ceramic and veneering porcelain complex

目的:测定烧结次数对渗透铝瓷-饰面瓷复合材料颜色稳定性的影响,为临床实际应用提供实验依据。方法:选用自行研制的AG2及VitaIn-CeramAL2色系渗透玻璃粉,对牙科计算机辅助设计辅助制作,用氧化铝块进行渗透,制作10mm×10mm×1mm的基底样本,并在其上构筑VitadurAlphaB2色不透明牙本质瓷和牙本质瓷,经过8次反复烧结,用MinoltaCR-321色彩色差计对颜色结果进行测定。并将烧结前后的样本在扫描电镜下观察。结果:多次烧结对两种颜色渗透铝瓷基底的颜色影响较小,两种颜色基底材料饰面瓷后都在第1次烧结和第2次烧结后颜色变化较大,表现为明度值降低,b值和饱和度值升高,色相角变化不明显。而第3次烧结后各次烧结的色差变化很小,颜色相对稳定。基底材料构筑饰面瓷后经过8次烧结后的饰面瓷玻璃相结构中出现很多晶相结构。结论:渗透铝瓷基底颜色受多次烧结影响不大,基底材料饰面瓷后经多次烧结变色主要出现在第1次与第2次间,临床上多次烧结对渗透铝瓷-饰面瓷复合材料颜色的影响很小。

AIM: To assay the influence of repeated firings on the color stability of the glass infiltration alumina core ceramic and veneering porcelain complex and to provide experimental basis for clinical application. METHODS: Dental computer aided design(CAD)/computer aided manufacture(CAM) alumina block was infiltrated by AG2 and Vita In Ceram AL2 color serials of infiltration glass powder made by ourselves. Basal specimens were made by size 10 mm×10 mm×1 mm. Vitadur Alpha B2 color opaque dentine and dentine veneering porcelain were added to these core ceramics.Specimens were sintered up to 8 times. Color results were measured by Minolta CR 321 colorimeter.The samples before and after sintering were observed by scanning electron microscope(SEM). RESULTS:There was little influence on the color of the two color groups of core ceramics by repeated firings. When the core ceramics were veneered, color changes were observed between the first firing cycle and the second firing cycle, these color changes were: light value was decreased,b value and chroma were increased, the change of hue was little.While after the third firing, little color change was found.Crystal phase structure was observed in the veneering porcelain after 8 times of sintering. CONCLUSION:There is little influencing on the basal color of infiltration alumina core ceramic after repeated firings.The color changes of the core ceramic were mainly observed between the first firing cycle and the second firing cycle. The color of infiltration alumina core ceramic and the core veneered porcelain complex are relatively stable after repeated firing cycles at clinic condition.