Comparison of fabricated and custom made shade tabs with different color measurement devices

The aim of this study is to compare CIE L*, a*, b*, Cab and ΔE values and evaluate the correlation between spectrophotometer and colorimeter devices' shade tabs for the most frequently encountered 2 L-M-R and 3 L-M-R shades of the Vita Toothguide 3D Master shade guide compared to metal supported surface and crown formed custom made shade tabs which have identical labial surfaces with 3D Master shade tabs and consist ideal thickness of dentine and dentine-enamel porcelain. For the half of the surface and crown shaped custom made shade tabs OP2 was applied, and OP3 colored opaque porcelain was applied to the other half. Dentine porcelain solely was applied to half of the surface and crown shaped shade tabs and dentine-enamel porcelain adhering to the the manufacturer's instructions was applied to the other half. All samples were measured with strip crowns that allow measurement from the middle, 10 times with the Vita Easyshade V and three times with the Minolta CR-321 in a black box. The analysed data shows a strong positive correlation between spectrophotometer and colorimeter devices for the b* values in all groups; the a* values in all groups except for the 3D Master group and in L* values only for the 3D Master group. The measured 3D Master chroma values with both of the devices are found to be lower than the custom made shade tab values for each shade. All of the L*, a*, b* and chroma values for all shades measured with the colorimeter are lower than the spectrophotometer measured values. The ΔE values between the 3D Master group and the other groups measured with both devices were found to be clinically unacceptable. There has been found no statistically significant difference between the average values of L* and b* for both of the devices, the average a* values for the spectrophotometer for the crown or surface shaped shade tabs in comparison within the groups. The average a *, b *, chroma and ΔE values measured with both devices for custom made shade tabs with metal substructure were found to be different from the fabricated shade tabs. The use of custom-made metal-supported ceramic shade tabs or the production of fabricated shade tabs with metal substructure and ideal porcelain thickness can provide aesthetically more successful restorations for the right shade sellection. Keywords: Shade tabs, metal supported ceramics, spectrophotometer, colorimeter