earticle

영어

Purpose: This study was conducted to investigate alloys spectrophotometrically including yttrium of nickel-chromium (Ni-Cr) alloys, which are used as substitutes for the regulation of beryllium and provide helpful improvements in Ni-Cr alloys. Methods: Four groups of specimens (ZN, ZY, SN and EM) were prepared for analysis. Color parameters were measured with a spectrophotometer, and color difference (ΔE*) was calculated. The t-test and one-way analysis of variance test were used to determine significant difference, and the Tukey test was used to identify where the differences were. To measure the spectroscopic reflectivity, the spectroscopic reflectance was measured and converted into CIE L*, a*, b* color system. Results: The ΔE* value of each metal ceramic group after opaque firing of Ni-Cr alloy with and without yttrium was <2, and the total group color difference (ΔE*) was below 1 in the dentin ceramic all experimental group. However, the a* and b* values of the metal ceramic groups were higher than that in the lithium disilicate all ceramic group, and the chroma was higher than the natural tooth. The brightness of all experimental groups was similar to that of the shade guide sample. Conclusion: Yttrium added to Ni-Cr alloys showed similar CIE L*, a*, b* values to Ni-Cr alloys that did not contain yttrium, indicating that yttrium had no effect on color in metallic ceramic systems.