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Introduction/Objective. The objective of this study was to perform colorimetric comparison between two shade guides used for visual tooth whitening monitoring. Methods. VITA Bleachedguide 3D-Master (BG) and value scale of VITA classical A1–D4 (VC) were evaluated (n = 3) using a non-contact spectroradiometer. Ranges, distribution, and correlation among color parameters were evaluated using CIEDE2000 color difference formula. In addition, optimized whiteness index for dentistry (WID), and Yellowness Index E313 (YI) were analyzed. ANOVA and Fisher’s PLSD test at a 0.05 level of significance were used in statistical analysis. Results. The lightness (L’), chroma (C’), and hue (h’) ranges for BG were 20.4, 25.9, and 19.1, respectively. The corresponding ranges for VC were 15.3, 10.9, and 20.6. R2 values for individual color coordinate/tab arrangement were higher for BG than VC. The same is true for R2 values of pairs of color coordinates for BG/VC: L’C’ = 0.89/0.33, L’h’ = 0.88/0.53, and C’h’ = 0.70/0.51. BG also exhibited better agreement between the manufacturer’s tab arrangement with ΔE’, WID and YI. The ΔE’ between the lightest and the darkest BG and VC tab were 20.6 and 13.2, respectively. The average ΔE’ among the adjacent tabs were 1.9 (0.5) for BG (corresponding to two shade guide units, SGU) and 3.0 (1.0) for VC (1 SGU). Conclusion. VITA Bleachedguide 3D-Master exhibited wider L’, C’, ΔE’, WID, and YI ranges compared to value scale of VITA classical A1–D4 shade guide and better distribution of evaluated color parameters. This, along with the presence of several shades lighter than B1 of VC, recommends the use of BG for visual evaluation of tooth whitening efficacy.

This multicenter study evaluated the effect of harmonizing spectrophotometric (d/8°) color measurements by using actual dental materials of clinically relevant thickness and translucency as "calibration tiles." Ten tooth‐colored, 1‐mm thick, resin‐ and ceramic‐based materials were tested at the coordinating center (CC) and six research sites (RS). Correction factors were calculated for each material and each site to obtain the corrected reflection spectra from the non‐corrected data set. Non‐corrected (NC) and corrected (C) reflection values were converted into CIEDE2000 and CIELAB color parameters for the following comparisons: CC vs RSNC and CC vs RSC, between RSNC vs RSNC and RSC vs RSC pairs, and among RS separately (α = 0.05). Mean color differences for CC vs RSNC and corresponding CC vs RSC values were ΔE00 = 4.2 (2.6) and ΔE00 = 0.7 (0.6), respectively. Corresponding values for RSNC vs RSNC and RSC vs RSC specimen pairs were ΔE00 = 5.9 (2.9) and ΔE00 = 1.0 (0.5), respectively. The CIEDE2000 NC vs C comparison for each research site separately ranged from 0.5 to 8.5. Color differences of CC vs RSC and RSC vs RSC pairs decreased 83% to 84.5% as compared with respective color differences for non‐corrected research site measurements and was RS dependent (P <.001). The obtained results validated the proposed method of harmonizing color measurements for dental application as a reliable quality control tool for dental research laboratories and industry. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the instrumental and visual color adjustment potential (CAP‐I, CAP‐V), of resin composites. Methods: Resin composites tested were Omnichroma, Filtek Supreme Ultra, TPH Spectra, Herculite Ultra, and Tetric EvoCeram. Two types of specimens, "dual" and "single" were evaluated. For dual specimens, class I preparations (4 mm‐diameter, 2 mm‐depth), were created in denture teeth and restored with test resin composites. For single specimens, replications of denture teeth were created using the test resin composites (n = 5) and compared with unrestored denture teeth. Reflectance values were obtained using a spectroradiometer. CAP‐I and CAP‐V were calculated. Fisher PLSD intervals for comparison of means were calculated at the 0.05 level of significance. Results: CAP‐I ranged between 0.02 and 0.67. The Fisher PLSD interval for comparisons between single/dual color differences was 0.09 (P < .0001, power 1.0) and for comparisons between materials and shades 0.18 and 0.33, respectively (P < .0001, power 1.0). CAP‐V ranged between 0.16 and 0.60. The Fisher PLSD interval for comparisons between single/dual visual color differences was 0.05 (P < .0001, power 1.0) and 0.08 and 0.14 for comparisons between materials and shades, respectively (P < .0001, except Herculite Ultra‐Tetric EvoCeram and certain shade pairs). Conclusions: Instrumental color differences and visual rating of single specimens were the greatest for Omnichroma, indicating the largest mismatch, while the instrumental and visual color differences of dual specimens were the smallest. Omnichroma had the most pronounced CAP‐I followed by Tetric EvoCeram>TPH Spectra = Filtek Supreme Ultra >Herculite Ultra. Similarly, Omnichroma exhibited the most pronounced CAP‐V followed by Tetric EvoCeram>TPH Spectra = Herculite Ultra = Filtek Supreme Ultra. Clinical significance: Resin composites with pronounced CAP blends with surrounding enamel and dentin, resulting in reduced color differences and therefore improving the esthetic appearance of the restoration, simplifying the shade matching and compensating for any color mismatch. [ABSTRACT FROM AUTHOR]