4种厚度IPS e.max Press核瓷遮色性能的研究

目的研究IPS e.max Press核瓷的厚度对于修复体遮色性能的影响。方法制作4组厚度分别为0.8 mm、1.2 mm、1.6 mm、2.0 mm的IPS e.max Press圆盘形试件各5个。将试件分别置于黑、白背景上,使用SolidSpec-3700分光光度计测量试件分别在黑色背景和白色背景上的亮度,并计算对比度;ShadeEye NCC电脑比色仪测量色度值并计算4种厚度试件的色差,对数据进行统计学分析。结果试件在黑色、白色背景上的对比度随着瓷层厚度增加而增加,色差随瓷层厚度增加而降低。厚度0.8 mm、1.2 mm、1.6 mm、2.0 mm试件的色差分别为18.74、16.58、12.64、8.08,对比度分别为0.62、0.73、0.80、1.88。4组试件在黑、白背景下的色差差异具有统计学意义(F=77.97,P<0.01),但4组试件的色差均大于临床可接受的最低色差6.8,对比度差异也具有统计学意义(F=226.99,P<0.01)。结论 IPS e.max Press核瓷随厚度增加能显著增加色遮蔽性,但在严重变色牙及金属桩核表面应谨慎使用。

Effect of percelain thicknesses on the masking ability of IPS e.max all-ceramic restoration

Objective To evaluate the effect of different thickness of core porcelain on the masking ability of IPS e. max all-ceramic restoration. Methods Disk-shaped IPS e. max Press specimens （0.8, 1.2, 1.6, or 2.0 mm in thick- ness） were fabricated, five disks per group. Contrast ratio of specimen were measured with a spectrophotometer against black and white backgrounds. Color parameters of samples were measured with ShadeEye Ncc, and calculate the color difference （AE） of samples in each thickness. The data were statistically analyzed. Results Increasing the disk thick- ness resulted in increase of contrast ratio and decrease of AE values of the specimens against black and white back- grounds. Contrast ratio and AE of specimens with different thickness had significant diftrenee （P 〈0.001 ）. Conclusion The thickness of IPS e. max Press exhibits significant influence on the masking ability. However, IPS e. max Press should be used with caution in severe discolored teeth and metal post surface.