金属桩核表面遮色对玻璃陶瓷冠颜色和边缘适合性的影响

A study on color-masking Co-Cr mental post-cores of color and marginal fit of glass-ceramic crowns

目的:研究钴铬合金金属桩核遮色后对二硅酸锂全瓷冠修复系统的颜色及颈边缘适合性的影响。方法:选取完整离体行根管治疗和标准基牙、桩道预备后,分别制作钴铬合金桩核和遮色钴铬合金桩核各10个,分别制作A2色二硅酸锂玻璃陶瓷冠。采用Minolta CM-700 d分光测色仪,测试两种桩核背景下全瓷冠唇面中1/3区域的颜色参数L!、a!、b!值,计算并比较色差△E。在100倍体视显微镜下观察各冠边缘与离体牙之间的垂直距离并对比分析边缘适合性。结果:两桩核组背景下全瓷冠的L!、a!、b!值的差异均有统计学意义。钴铬合金桩核组的色差超过临床可接受水平(△E>2);遮色钴铬合金桩核组的色差不能为肉眼所识别(△E<1.5)。钴铬合金桩核组颈边缘适合性为(63.34±7.8)μm,遮色钴铬合金桩核组颈边缘适合性为(87.47±11.3)μm,两组间差异具有统计学意义(P<0.05),但适合性大小均在临床可接受范围内。结论:在玻璃陶瓷修复时,可在金属桩核的核表面遮色,但需注意其边缘适合性。

Objective：To study the color-masking Co-Cr alloy post-cores on color and marginal fit of lithium dicilicate glass-ceramic crown. Methods：An intact extracted maxillary central incisor was received endodontic treatment and the post＇ s root canal was prepared. They were divided into two groups randomly that each ten of color-masking Co-Cr alloy postcores and Co-Cr alloy post-cores were made for these root canals, and A2 lithium dicilicate glass-ceramic crowns were manufactured for every prepared post-core. The color parameter values（ L^＋, a^＋ and b^＋ ） of the middle 1/3 of the crown were measured by the CM-700 d spectrophotometric tester for the two groups, and the AE were calculated. Distance between each crown＇ s margin and the abutment was recorded at 50 points randomly using by measuring microscope. Results ： It was obvious different on the values of L^＋, a^＋, and b^＋ in the two groups. The color difference of color-masking Co-Cr alloy post-cores could not be identified by the naked eye（ △E 〈 1.5 ） ,while the AE value in the Co-Cr alloy post-cores group was beyond the level that could be accepted on clinic （ △ E 〉 2 ）. The marginal fit of the Co-Cr post-cores was （ 63.34± 7.8 ） μm, color-masking Co-Cr post-cores was （ 87. 47 ± 11.3 ） μm, that were all clinically acceptable. Conclusion ： If the metal alloy post-core is needed in the glass-ceramic system, the color-masking Co-Cr alloy post-cores can be considered, but its adaptation must been consideration.