Department of Prosthodontics, Başkent University, Ankara, Turkey.
J Prosthet Dent. 2011 Jul;106(1):38-47. doi: 10.1016/S0022-3913(11)60091-7.
Even though metal ceramic restorations (MCRs) are widely used by clinicians, the influence of the metal on the color of overlaying porcelain is unknown.
The purpose of this study was to analyze the color alterations of different types of metal ceramic alloys during several stages of metal surface preparation and to determine the effect of those changes on the resulting color of opaque porcelain (OP).
Seven different types of alloys (3 base metal, 3 noble, and 1 high noble) were used to prepare disk-shaped specimens (1 mm × 10 mm, n=3), followed by OP application (0.1 mm). Lab* values of specimens were recorded after different stages of metal surface preparation (ingot, after casting, after oxidation, and after the OP application) in addition to the shade tab of OP B1 (target shade). Lab* values of alloys were measured from the ingot structure to the OP application stage and statistically analyzed (Repeated measures ANOVA, and Bonferroni corrected paired t test, α=.05). Lab* values of OP applied groups and the OP shade tab (target shade) were analyzed (1-way ANOVA with Dunnett's multiple comparison test, α=.05). The color differences of the target shade both before and after OP application were calculated and statistically analyzed (1-way ANOVA, Ryan-Einot-Gabriel-Welsch Multiple Range Test, α=.05).
The L* values of all alloys changed significantly after each stage except for 2 alloys (V-Deltaloy SF (N-VDSF)) and (Gnathos Plus (HN-GP)) after casting and airborne-particle abrasion (P<.05). The a* value of all alloys increased after casting. Changes in the a* coordinate were significant except for one of the base metal alloys (P<.05). The a* coordinate changes of alloys showed variation in direction after oxidation and OP application (P<.05). The b* coordinate changes of alloys showed variation in direction after each stage (P<.05). The Lab* values of some OP applied alloys were significantly different from that of the OP shade tab (P<.05). Color difference values (ΔE (OP applied alloy-target shade)) of 2 OP-applied alloys (Cerapall 2 (N-CP2) and Ceradelta (N-CD)) were significantly different (P<.05) and higher than the other OP-applied alloys.
The achromatic color behavior of different alloys was all in the same direction at all metal surface preparation stages. The chromatic behavior of the different alloys was primarily towards the same direction after casting and airborne-particle abrasion, whereas it varied after oxidation and OP application. The color difference of OP for all alloys, regardless of their type, was not visually perceivable when compared to the target shade (ΔE<2.6).
尽管金属陶瓷修复体（MCR）被临床医生广泛使用，但金属对覆盖瓷颜色的影响尚不清楚。
本研究旨在分析不同类型金属陶瓷合金在金属表面处理的几个阶段的颜色变化，并确定这些变化对不透明瓷（OP）最终颜色的影响。
使用七种不同类型的合金（3 种贱金属、3 种贵金属和 1 种高贵金属）制备圆盘状试件（1mm×10mm，n=3），然后施加 OP（0.1mm）。在金属表面处理的不同阶段（锭、铸造后、氧化后和 OP 施加后）以及 OP B1 遮色片（目标遮色片）后，记录试件的 Lab值。从锭结构到 OP 施加阶段测量合金的 Lab值，并进行统计学分析（重复测量 ANOVA 和 Bonferroni 校正配对 t 检验，α=.05）。分析施加 OP 的各组和 OP 遮色片（目标遮色片）的 Lab*值（单因素方差分析，Dunnett 多重比较检验，α=.05）。计算并分析目标遮色片施加前后的颜色差异（单因素方差分析，Ryan-Einot-Gabriel-Welsch 多重范围检验，α=.05）。
除两种合金（V-Deltaloy SF（N-VDSF）和 Gnathos Plus（HN-GP））在铸造和喷丸处理后以及所有合金在氧化和 OP 施加后外，所有合金的 L值在每个阶段都有显著变化（P<.05）。所有合金的 a值在铸造后增加。除一种贱金属合金外，所有合金的 a坐标变化均有统计学意义（P<.05）。氧化和 OP 施加后，合金的 a坐标变化方向发生变化（P<.05）。合金的 b坐标变化在每个阶段都发生了方向变化（P<.05）。一些施加 OP 的合金的 Lab值与 OP 遮色片明显不同（P<.05）。两种 OP 施加合金（Cerapall 2（N-CP2）和 Ceradelta（N-CD））的颜色差异值（OP 施加合金-目标遮色片）（ΔE（OP 施加合金-目标遮色片））差异显著（P<.05），且高于其他 OP 施加合金。
不同合金在所有金属表面处理阶段的非彩色行为都朝着同一方向。不同合金在铸造和喷丸处理后，其彩色行为主要朝同一方向，但在氧化和 OP 施加后则发生变化。与目标遮色片相比（ΔE<2.6），所有类型合金的 OP 颜色差异在视觉上均不可察觉。
