Ge Jing, Wang Xin-zhi, Feng Hai-lan
Department of Prosthodontics, School and Hospital of Stomatology, Peking University, Beijing 100081, China.
Chin Med J (Engl). 2006 Oct 20;119(20):1715-20.
For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a metal post core. Therefore, this experiment was conducted to test the esthetical possibility of applying cast metal post core in a full ceramic crown restoration.
The color of full ceramic crowns on gold and Nickel-Chrome post cores was compared with the color of the same crowns on tooth colored post cores. Different try-in pastes were used to imitate the influence of a composite cementation on the color of different restorative combinations. The majority of patients could not detect any color difference less than DeltaE 1.8 between the two ceramic samples. So, DeltaE 1.8 was taken as the objective evaluative criterion for the evaluation of color matching and patients' satisfaction.
When the Empress 2 crown was combined with the gold alloy post core, the color of the resulting material was similar to that of a glass fiber reinforced resin post core (DeltaE = 0.3). The gold alloy post core and the try-in paste did not show a perceptible color change in the full ceramic crowns, which indicated that the color of the crowns might not be susceptible to change between lab and clinic as well as during the process of composite cementation. Without an opaque covering the Ni-Cr post core would cause an unacceptable color effect on the crown (DeltaE = 2.0), but with opaque covering, the color effect became more clinically satisfactory (DeltaE = 1.8).
It may be possible to apply a gold alloy post core in the Empress 2 full ceramic crown restoration when necessary. If a non-extractible Ni-Cr post core exists in the root canal, it might be possible to restore the tooth with an Empress 2 crown after covering the labial surface of the core with one layer of opaque resin cement.
出于美学考虑，全瓷冠修复通常使用牙本质颜色的桩核材料。然而，在某些情况下，临床医生不得不考虑将全瓷冠与金属桩核联合使用。因此，进行本实验以测试在全瓷冠修复中应用铸造金属桩核的美学可能性。
比较了金合金和镍铬合金桩核上全瓷冠的颜色与牙色桩核上相同冠的颜色。使用不同的试戴糊剂来模拟复合树脂粘结对不同修复组合颜色的影响。大多数患者无法察觉两个陶瓷样本之间色差小于ΔE 1.8的任何颜色差异。因此，将ΔE 1.8作为评估颜色匹配和患者满意度的客观评价标准。
当Empress 2全瓷冠与金合金桩核联合使用时，所得材料的颜色与玻璃纤维增强树脂桩核的颜色相似（ΔE = 0.3）。金合金桩核和试戴糊剂在全瓷冠中未显示出可察觉的颜色变化，这表明冠的颜色在实验室和临床之间以及复合树脂粘结过程中可能不易改变。在没有不透明覆盖层的情况下，镍铬合金桩核会对冠产生不可接受的颜色效果（ΔE = 2.0），但有不透明覆盖层时，颜色效果在临床上更令人满意（ΔE = 1.8）。
必要时，在Empress 2全瓷冠修复中应用金合金桩核是可行的。如果根管内存在不可取出的镍铬合金桩核，在用一层不透明树脂粘结剂覆盖桩核唇面后，可能可以用Empress 2全瓷冠修复患牙。
