不同桩核对Lava锆瓷冠颜色影响的实验研究

Influence of Four Kinds of Post-cores on Color of Lava All Ceramic System

目的:研究遮色钴铬合金桩核、氧化锆桩核、纤维桩树脂核、钴铬合金金属桩核对二氧化锆全瓷冠(Lava)颜色的影响。方法:选取因牙周炎拔除的完整上颌中切牙,在釉牙骨质界冠方2.0mm处截冠,完善根管充填治疗和桩道预备,分别制作4种不同桩核预备体各10个,每个桩核再相应制作1个Lava二氧化锆全瓷冠,内冠厚0.5mm,饰面瓷0.7mm。采用Minolta CM一700d分光测色仪,测试4种桩核背景下Lava锆瓷冠唇面中1/3区域L~*、a~*、b~*值,分别进行完全随机设计的单因素方差分析和两两比较的LED检验,并根据公式计算和比较色差△E。结果:4种不同桩核背景下Lava锆瓷冠的L~*、a~*、b~*值间差异有统计学意义(FL=136.206,PL=0.000;Fa=3.454,Pa=0.026;Fb=6.172,Pb=0.000)。3组牙色桩核的色差则均不能为肉眼所识别(△E<1.5),钴铬合金桩核组的色差超过临床可接受水平(△E>2)。结论:临床应用锆瓷冠(Lava)进行修复时(特别是前牙区),不建议使用金属桩核。

Objective：To study the influence of four kinds of post-cores on the color of Lava zirconia all ceramic system.Methods：An intact extracted maxillary central incisor was selected and excised 2mm coronal to the enamel-cementum.The tooth received endodontic treatment and root canal preparation.Four kinds of post-cores were prepared（n=10）.Lava zirconia crowns were manufactured to fit the post-cores.The thicknesses of inner crown and enamel porcelain were 0.5mm and 0.7mm respectively.The color parameters（L^＊,a^＊and b^＊）of the middle1/3of the crown were measured by the CM-700 dspectrophotometry.The values of L^＊,a^＊,and b^＊were compared by an ANOVA and a LED test,and the△E was calculated.Results：There were significant differences on the values of L^＊,a^＊,and b^＊in four groups（P〈0.05）.The color difference of three teeth-color groups could not be identified by the naked eye（△E〈1.5）.While the△E values in the Co-Cr alloy post-cores group was beyond the clinical accepted level（△E〉2）.Conclusion：The metal alloy post-core was not recommended for Lava zirconia crown,especially in the anterior area.