高明度ND1代型材料表面4种全瓷冠光学特性比较

The optical property of four different all-ceramic crowns on the light color core ND1 substructure

目的：评估高明度ND1代型材料表面4种全瓷底冠光学参数CIE L＊a＊b＊值、透射比,烧结A2体瓷后与A2色片色差ΔE。方法：制作ND1色基牙,分别戴入Procera氧化铝、Procera氧化锆、Lava氧化锆、IPS E.max低透铸瓷底冠,分光光度比色仪拍摄并在颈1/3、体1/3、切1/3随机选点测色。4组底冠烧结A2体瓷粉后再戴入ND1色基牙（总瓷层厚度控制1.5mm）,分光光度比色仪测色,数据进行单因素方差分析、Bonferroni多重均数比较。结果：4组底冠均提高基牙的L＊值,彩度a＊值下降、b＊值变化不一致,多数组间L＊a＊b＊值有统计学差异。烧结体瓷后各组冠L＊值明显下降,彩度a＊、b＊值上升。各部分与A2总体色差减小（ΔE=1.27~4.17）。4组底冠透光率均值依次为E.max-LT A2〉Pro-Alu〉Lava-Zir〉ProZir。结论：ND1基牙戴入4组全瓷底冠后明度、彩度差异大。底冠烧结体瓷后明度差异减少,彩度差异较大。Lava-Zir和IPS E.max体瓷组色差超过临床可接受度。铸造陶瓷和氧化铝底冠通透性高于2种氧化锆底冠。

Objective： To evaluate the optical property of the light color core substructure ND1 overlaid by 4 different all-ceramic crowns respectively and to study the color difference between the crowns and target tab. Methods： Light color（ ND1 ） substructures were made and were respectively tried in 4 groups of all- ceramic crowns （ Proeera alumina, Procera zireonia, Lava zirconia and IPS E. max glass-ceramic lithium disilicate-reinforced monolithic, n = 10）. The CIE L ＊ , a ＊ , b ＊ values of the cervical part, body and incisal site of the samples were recorded and analyzed by a speetrophotometer before and after veneer. The color difference between the all-ceramic crowns and target A2 dentin tab was evaluated. The spectral integral transmittance of the 4 copings was measured by a spectrophotometer. Results： The L ＊ values of the abutments was increased by all- ceramic copings of the 4 groups, a ＊ values were decreased but b ＊ changed inconsistently. After veneer, the L ＊ values of all the copings declined significantly, the values of a ＊ and b ＊ increased. When compared with A2 tab, the AE of the crowns was 1.27 -4.17. The mean value range of the transmittance of the coping was ： E. max- LT A2 〉 Pro- Alu 〉 Lava- Zir 〉 Pro- Zir. Conclusion： The lightness, hue and light transmittance of the 4 ceramic copings are different. After veneer with A2 dentine, the difference of the lightness is declined but the difference of the hue is signifi- cant. The color difference of the Lava-Zir and IPS E. max is clinically unacceptable.