A Study Of Three Factors On The Color Difference Of Metal Ceramic Restorations

In virtue of good shape, color and function, the metal ceramicrestoration has been one of the widely used means in clinical work. Ittakes the fancy of the patients. Natural and lifelike color of therestorations is the important aspect to show natural beauty of humanteeth.It is also the standard to determine that if the restoration issuccessful.In clinical work,the color difference between restorations andshade guide is often in existence. It is often affected by outsidesurroundings and different porcelain systems. In thisexperiment, CIE₁₉₇₆L^*a^*b^* color system and a digital camera andcomputer were selected to study the effect of backgrounds,light sourcesand porcelain systems on the color difference of metal ceramicrestorations. The results will provide some references for better colorselection.Partâ… : The color difference of metal ceramicrestorations on three different backgroundsObjective: To study the color difference of metal ceramic restorationsand VITA shade guide on three different backgrounds. Materials andMethods: Two types of metal ceramic restorations were made on thebasis of the same die. A₂ shade slice in the shade guide was selected to be the contrast. Gray,black and red backgrounds, CIE₁₉₇₆L^*a^*b^* colorsystem, a digital camera, computer and a standard light source wereselected to measure and compare the characteristic of A₂ shade slice inthe shade guide and two types of metal ceramic restorations. Results: Tothe same type of metal ceramic restorations,the color difference waslarger than 1.5NBS on three different backgrounds dramatically.Nomatter what background, the color difference between metal ceramicrestorations and VITA shade guide was larger than 1.5NBS. Thedifference was the biggest on red background.And it took second place onblack background.On gray background, it was the smallest.On the samebackground,the color difference between nichrome metal porcelaincrowns and noble metal porcelain crowns was larger than 1.5NBS.Ascompared to shade guide,the latter was better than the former.Conclusion: Color differences were found between the shade guide andmetal ceramic restorations on different backgrounds. The color of metalporcelain crowns on gray background was better than that on black andred background.Partâ…¡: The color difference of metal ceramicrestorations in three different light sourcesObjective: To study the color difference of metal ceramic restorationsand VITA shade guide in three different light sources. Materials andMethods: Two types of metal ceramic restorations were made on the basis of the same die. A₂ shade slice in the shade guide was selected to bethe contrast.Daylight, cool white light and warm white lightsources,CIE₁₉₇₆L^*a^*b^* color system, a digital camera, computer andgray background were selected to measure and compare the characteristicof A₂ shade slice in the shade guide and two types of metal ceramicrestorations. Results: To the same type of metal ceramic restorations,thecolor difference was larger than 1.5NBS in three different light sourcesdramatically.No matter what light source, the color difference betweenmetal ceramic restorations and VITA shade guide was larger than1.5NBS. The difference was the smallest in the daylight source. In thesame light source,the color difference between nichrome metal porcelaincrowns and noble metal porcelain crowns was larger than 1.5NBS.Conclusion: Color differences were found between the shade guide andmetal ceramic restorations in different light sources. The color of metalporcelain crowns in the daylight source was better than that in warmwhite and cool white light sources.Partâ…¢: Effect of the variation of porcelain on thecolor difference of metal ceramic restorationObjective:To study the effect of the different porcelain systems on thecolor difference of metal ceramic restorations and VITA shade guide.Materials and Methods: Two types of metal ceramic restorations weremade on the basis of the same die. A₂ shade slice in the shade guide were selected to be the contrast. Vita VMK 95 A₂ and DeguDent KISS A₂porcelain systems, CIE₁₉₇₆L^*a^*b^* color system, a digital camera,computer, a daylight source and gray background were selected tomeasure and compare the characteristic of A₂ shade slice in the shadeguide and two types of metal ceramic restorations. Results:There is nodifference of value between two porcelain systems.But the hue andchroma had significant difference.To the chroma,Vita VMK 95 porcelainsystem is larger than DeguDent KISS porcelain system.The colordifference between Vita VMK 95 porcelain system and shade guide issmaller than that of DeguDent KISS porcelain system. Conclusion:To thehue,Vita VMK 95 porcelain power was more yellow and redder thanDeguDent KISS porcelain power. Different porcelain system had aneffect on the color of metal ceramic restorations. The shade guide shouldcoordinate with porcelain system then you can achieve a maximum effect.