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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 article discusses a study that compared clinical in-office bleaching of 6% hydrogen peroxide (HP) with and without light, plus three nights of treatment with 16% carbamide peroxide (CP). Visual and instrumental color measurements were performed on 77 subjects immediately, one week, and two weeks after in-office bleaching. Data were analyzed at 0.05 level of significance using paired t-test and patient surveys. Results indicated shades were 6 to 7 shades lighter visually depending on light or no light treatment respectively, and 7.4 with respect to ΔE*. Some mild tooth or gingival sensitivity was reported. The study concluded that bleaching was significantly greater between light and no-light groups visually, but not instrumentally. [ABSTRACT FROM AUTHOR]

Objective To evaluate in vitro the fluorescence properties of extracted human teeth whitened with 40% hydrogen peroxide. Materials and Methods A total of 28 extracted human teeth were pumiced for 1 minute using a low-speed dental handpiece and a disposable rubber cup. Pre-whitening fluorescence measurements (T0), maximum excitation (Exmax), maximum emission (Emmax), and maximum intensity ( Imax108), were performed using a spectrofluorometer. After T0 measurements, the teeth were whitened using the in-office method with 40% hydrogen peroxide, three times for 20 minutes. The fluorescence parameters were measured under the same conditions 7 and 14 days after bleaching (T1 and T2, respectively). Results Exmax exhibited a broader range 7 days after whitening and decreased after 14 days. The Emmax and Imax108 displayed a narrower range after whitening. The mean Exmax differed significantly between the time points ( F = 20.09. P < .001). The corresponding analysis for the mean Emmax differed significantly between the time points ( F = 16.69, P < .001). The same was true for the mean Imax108 ( F = 9.69, P < .001). Conclusions Within the limitations of this study, whitening provoked statistically significant changes in fluorescence of the intact teeth in vitro. Clinical significance The appearance of human teeth and dental materials and their changes upon aging and exposure to different agents (staining, whitening) is a topic of great relevance to esthetic dentistry. While some appearance parameters, such as color, translucency, and gloss, have been thoroughly studied, fluorescence and its influence on overall tooth appearance is still not well understood, yet it has influenced the development of fluorescence emitting restorative materials. [ABSTRACT FROM AUTHOR]