Ozcelik Tuncer Burak, Yilmaz Burak, Ozcan Isil, Kircelli Cem
Department of Prosthodontics, Faculty of Dentistry, Baskent University, Ankara, Turkey.
J Prosthet Dent. 2008 Mar;99(3):193-202. doi: 10.1016/S0022-3913(08)60043-8.
The popularity of base metal alloys has considerably increased in recent years because of their superior mechanical properties as well as the high cost of noble alloys. However, there is disagreement about their effect on the opaque porcelain color and the color differences among base metal alloys.
The purpose of this in vitro study was to determine and compare the influence of various commercially available base metal alloys (excluding titanium-based systems) on the resulting color of opaque porcelain with the use of a colorimetric device.
Fourteen different types of Ni-Cr and 3 different types of Co-Cr porcelain bonding alloys were selected with a Au-Pd alloy (V-Delta SF) as the control group for colorimetric measurements and determination of color shift after opaque application. Shade B1 of an opaque porcelain (IPS d.SIGN Opaquer) was applied (0.1 mm) to all specimens (16 mm x 1 mm). The color coordinates of each specimen were measured with a chromameter. The data were displayed in L*, a*, and b* values according to the CIELAB system, and the color differences (DeltaE) between base metal alloys and the control group were calculated. Data were statistically analyzed with 1-way ANOVA (alpha=.05). The ANOVA was followed by Dunnett's multiple comparison test for comparisons with the control group to determine specifically which groups were significantly different from the control group.
The L* value of only 1 base metal alloy was significantly different from the control group (P<.001). All base metal alloy groups except 3 had a* values which were significantly different from the control group a* value (P=.001 for Rexillium III, P=.008 for Heracles N, and P<.001 for the remaining 12 alloys), whereas only 3 base metal alloys were not statistically significantly different from the control group in the means of b* values (P<.001). All base metal alloys to which opaque porcelain was applied had significantly different DeltaE values in comparison with the control group (P<.001).
The data of the study indicated that a 0.1-mm-thick layer of opaque porcelain applied on the Ni-Cr and Co-Cr alloys did not reliably reproduce the color of opaque porcelain. However, within the limitations of this study, the color differences of base metal alloys measured according to the control group are within clinically acceptable limits (DeltaE<3.5).
近年来，贱金属合金因其优越的机械性能以及贵金属合金的高成本而广受欢迎。然而，对于它们对不透明瓷颜色的影响以及贱金属合金之间的颜色差异存在分歧。
本体外研究的目的是使用比色装置确定并比较各种市售贱金属合金（不包括钛基系统）对不透明瓷最终颜色的影响。
选择了14种不同类型的镍铬合金和3种不同类型的钴铬烤瓷合金，以一种金钯合金（V-Delta SF）作为对照组进行比色测量，并在施加不透明瓷后测定颜色变化。将一种不透明瓷（IPS d.SIGN Opaquer）的B1色号（0.1毫米厚）施加于所有试样（16毫米×1毫米）。用色度计测量每个试样的颜色坐标。数据根据CIELAB系统以L*、a和b值显示，并计算贱金属合金与对照组之间的颜色差异（DeltaE）。数据采用单因素方差分析进行统计学分析（α = 0.05）。方差分析后采用Dunnett多重比较检验与对照组进行比较，以具体确定哪些组与对照组有显著差异。
只有1种贱金属合金的L值与对照组有显著差异（P < 0.001）。除3种贱金属合金组外，所有贱金属合金组的a值均与对照组的a值有显著差异（Rexillium III的P = 0.001，Heracles N的P = 0.008，其余12种合金的P < 0.001），而只有3种贱金属合金在b值均值上与对照组无统计学显著差异（P < 0.001）。与对照组相比，所有施加了不透明瓷的贱金属合金的DeltaE值均有显著差异（P < 0.001）。
研究数据表明，在镍铬合金和钴铬合金上施加0.1毫米厚的不透明瓷层不能可靠地再现不透明瓷的颜色。然而，在本研究的局限性内，根据对照组测量的贱金属合金的颜色差异在临床可接受范围内（DeltaE < 3.5）。
