An in vitro spectrpohotometric anakysis of colour differences between composite resins and their shade guides

The purpose of this study was to compare the colour of the stock shade guides of resin composite products provided by the manufacturers and the colour of the custom made samples fabricated from the same shade of the resin composite restorative materials. The objective was to determine the colour difference that exists between the sample to be matched and the standard and/or how much of a difference is acceptable in a given clinical situation. Three different light-activated resin composite specimens and shade guides of same thickness were evaluated by a spectrophotometric analysis. Colour measurement data was plotted in the CTELAB color space. All resin samples showed statistically significant color variations when compared to thpir respective shade tabs.The results highlight the inadequacies of stock shade guides and recommend the fabrication of custom shade guides from the restorative material itself for improved shade reproduction.