Vitapan Classical Research Articles

Online colour training system for dental students: a comprehensive assessment of different training protocols.

The purpose of this study was to evaluate the training effect and to determine the optimal training protocol for a recently developed online colour training system. Seventy students participated in the evaluation. They first completed a baseline test with shade guides (SGT) and the training system (TST), and then trained with one of the three system training methods (Basic colour training for group E1, Vitapan Classical for E2, and Vitapan 3D-Master for E3) or shade guides (group C1) for 4days. The control group (C2) received no training. The same test was performed after training and they finally completed a questionnaire. The correct matches after training increased in three experimental groups and group C1. Among experimental groups, the greatest improvement of correct matching number was achieved by group E3 (4·00±1·88 in SGT, 4·29±2·73 in TST), followed by E2 (2·29±2·73 in SGT, 3·50±3·03 in TST) and E1 (2·00±2·60 in SGT, 1·93±2·96 in TST). The difference between E3 and E1 was statistically significant (P=0·036 in SGT, 0·026 in TST). The total average training time was shorter in group E2 (15·39±4·22min) and E3 (17·63±5·22min), with no significant difference between them. Subjective evaluations revealed that self-confidence in colour matching were improved greater in group C1 and E3. In conclusion, all tested sections of the system effectively improved students' colour-matching ability. Among system training methods, Vitapan 3D-Master showed the best performance; it enabled greater shade-matching improvement, it saved time and was superior in subjective evaluations.

Evaluation of an optimized shade guide made from porcelain powder mixtures

Color errors associated with current shade guides and problems with color selection and duplication are still challenging for restorative dentists. The purpose of this study was to evaluate an optimized shade guide for visual shade duplication. Color distributions (L*, a*, and b*) of the maxillary left central incisors of 236 participants, whose ages ranged from 20 to 60, were measured with a spectrophotometer. Based on this color map, an optimized shade guide was designed with 14 shade tabs evenly distributed within the given color range of the natural incisors. The shade tabs were fabricated with porcelain powder mixtures and conventional laboratory procedures. A comparison of shade duplication by using the optimized and Vitapan Classical shade guides was conducted. Thirty Chinese participants were involved, and the colors of the left maxillary incisors were selected by using 2 shade guides. Metal ceramic crowns were fabricated according to the results of the shade selection. The colors of the shade tabs, natural teeth, and the ceramic crowns were measured with a spectrophotometer. The color differences among the natural teeth, the shade tabs, and the corresponding metal ceramic crowns were calculated and analyzed (α=.017). Significant differences were found in both phases of shade determination and shade duplication (P<.017). The total number of color errors with the optimized shade guide was 3.5, which was significantly less than that of Vitapan, 5.1 (P<.001). The optimized shade guide system improved performance not only in the color selection phase but also in the color of the fabricated crowns.

Color stability over time of three resin-based restorative materials stored dry and in artificial saliva.

To evaluate the color match of different composite resins relative to Vitapan Classical shade guide tab and their respective manufacturers' shade guide tabs as a function of time and storage. Three enamel shade A2 composite resins were used to fabricate 36 disk-shaped polymerized specimens (12 each), allocated into 2 groups of 6 and stored dry (GD) and in artificial saliva (GS). CIELAB coordinates from shade tabs and resin specimens immediately after polymerization (t0), and 24 hours (t1), 7 (t7), 14 (t14) and 21 (t21) days after polymerization were captured using a colorimeter. Color difference (ΔE00 ) between composite specimens and the reference tabs was calculated using the CIEDE2000 formula. The results were analyzed with repeated measures ANOVA, Tukey's HDS post-hoc test, and Student t test (p ≤ 0.05). Color of the three tested composites relative to Vita and their respective tabs significantly changed as a function of time until t14; however, between t14 and t21, no significant differences were found. No differences in color were found relative to storage at t14 and t21. ΔE00 values of specimens at t14 were significantly higher relative to their respective tabs than to Vitapan tab. For all brands color changed up to day 14, when it stabilized, regardless of whether composite specimens had been stored in artificial saliva or simply in a box. Vitapan tab presented a better color match than the manufacturers' tabs. The results found in this study demonstrated that the Vitapan Classical shade guide tab A2 provided a better color match than the respective shade guide tabs A2 supplied by the composite manufacturers. If custom shade tabs are to be made, however, they could be kept in a box and used as shade references from 14 days after being fabricated, when color stabilizes.

Comparison of the translucency of shaded zirconia all-ceramic systems.

PURPOSEThe purpose of this study was to evaluate and compare the translucency of shaded zirconia all-ceramic systems.MATERIALS AND METHODSTranslucency of 3 different zirconia all-ceramic systems colored by different techniques was compared with a lithium disilicate glass-ceramic (IPS e.max Press). Square-shaped specimens with 0.5 mm thickness were fabricated from In-Ceram YZ, ICE Zirkon and Katana systems in A1, A2 and A3.5 shades according to Vitapan Classical shade tab (n=11). Specimens were then veneered and glazed with corresponding veneer ceramic recommended by each zirconia system manufacturer and the total thickness was set to 1.5 mm. Translucency measurements were performed with VITA Easyshade Compact spectrophotometer after each stage and translucency parameter was calculated. Data were statistically analyzed with repeated measures ANOVA and Tukey multiple comparison test.RESULTSThe control group was significantly more translucent than the zirconia systems (P<.05). ICE Zirkon cores showed the least translucency; neither In-Ceram YZ nor Katana systems were superior to each other in terms of translucency. Translucency of all specimens was decreased after veneering, and the translucency rankings were changed.CONCLUSIONColoring technique did not have a significant effect on translucency of zirconia cores. Although zirconia systems were less translucent than lithium disilicate glass ceramic, they had partial translucency and there were translucency differences among the zirconia systems. Chroma affected the translucency of precolored zirconia cores.

Evaluation of Color Changes in the Vitapan Classical Shade Guide After Disinfection

The purpose of this study was to evaluate how one, two, and three years of simulated treatments affect the colors of Vitapan Classical Shade Guide tabs after being chemically disinfected. Ten shade tabs (one, control; nine, disinfection) were evaluated visually and by chromameter for color changes after disinfection. Results showed that 0.62 ΔE was found after three years of disinfection. The color changes in the shade guide tabs were perceptible or noticeable to the human eye in eight out of 45 shade tabs (17.8%) after two years and in 13 out of 45 shade tabs (28.9%) after three years of treatment. It was concluded that one shade guide should be retained as a control and periodically compared with the shade guide in use to determine when the shade tabs in use should be replaced or discarded.

Evaluation of an anatomic dual-laminate composite resin shade guide

BackgroundColor assessment in aesthetic dentistry is one of the most challenging steps for direct restorative treatment. Shade selection tools should be able to mimic closely the materials and layering technique used in the final restoration, hence the development of prefabricated anatomic dual-laminate shade guides. ObjectiveThis study aims to compare different shade selection techniques and determine the suitability of a prefabricated anatomic dual-laminate shade guide and its best mode of use compared to a conventional guide and a layered custom guide. Materials and methodsCIELab coordinates of different shade guides were assessed: Vitapan Classical (tab A2; Vita); Miris2 prefabricated anatomic dual-laminate shade guide, enamel WR tab on top of dentine S3 tab and nothing in-between (M2air) or glycerin gel (M2gly) or water (M2w); custom shade guide using prefabricated silicon moulds, Miris2 enamel WR composite resin moulded directly on dentine S3 pre-polymerised base (M2cus). The average values were obtained to calculate ΔE and compare the different shade selection techniques. Additional samples and measurements were made to compare Vitapan Classical shade tabs A1, A2 and A3 and all possible combinations of Miris2 and establish the closest matching shade (ΔE≤3.3). ResultsHigh ΔE values were found (6.51–9.11) when comparing M2air to Vita, M2gly M2w M2cus. Differences appeared acceptable (ΔE 2.09–2.99) between Vita, M2gly and M2w and M2cus. Seven combinations of M2 were found to match Vita tab A1 and A2 and three Miris2 combinations for Vita A3 (ΔE≤3.3). ConclusionsThe use of Miris2 prefabricated anatomic dual-laminate shade guide with interposition of water or glycerin between the enamel–dentine tabs demonstrated acceptable ΔE values when compared to Vitapan Classical and custom guides. A chart for matching Vita shades with various combinations of Miris2 enamel/dentine shades was produced to assist the clinician in obtaining acceptable restorations. Clinical significanceThe prefabricated anatomic dual-laminate shade guide is as efficient as a custom shade guide, facilitating clinical steps and saving material when doing composite resin restorations.

Visual and instrumental evaluation of color match ability of 2 shade guides on a ceramic system

There is limited information on the visual and instrumental evaluation of color match between a natural tooth and a ceramic crown. The purpose of this study was to evaluate the influence of 2 shade guides on color match, and to evaluate the relationship between color difference (ΔE) values and examiners' assessments of the color match in ceramic crowns. Thirty-three subjects were selected for a ceramic crown restoration of the maxillary central incisor. Two crowns were fabricated with selected shades from Vitapan Classical and Vita Toothguide 3D-Master shade guides for each subject. The color values of maxillary central incisors, selected shade tabs, and corresponding crowns were measured with a spectrophotometer. The ΔE values between the natural teeth and the crowns and between the selected shade tabs and the corresponding crowns were calculated for each subject and compared with the Student's t test (α=.05). In addition, 3 examiners visually evaluated the clinical acceptability of each crown on a scale from 1 to 6. The agreement among the examiners was assessed with the Kappa test. The scores of examiners for both shade guides were analyzed with the Wilcoxon signed rank test (α=.05). The results revealed that the color difference values between the teeth and the crowns fabricated with the selected shades from the Vita Toothguide 3D-Master shade guide were significantly smaller than those of the Vitapan Classical guide (P=.003). Similarly, the color difference values between the selected shade tabs from the Vita Toothguide 3D-Master guide and the corresponding crowns were significantly smaller than those of the Vitapan Classical guide (P=.001). However, the ΔE values obtained for both shade guides were within the clinically acceptable range (ΔE<3.7). The kappa values implied moderate agreement among the 3 examiners. The median value of the examiners' scores was 2, which denoted an acceptable color match. In addition, the recorded scores of the 3 examiners showed that there was no significant difference in terms of the color match between the crowns fabricated with either of the 2 shade guides. The ceramic crowns fabricated with the Vita Toothguide 3D-Master shade guide resulted in a closer color match to the natural teeth than those of the Vitapan Classical guide. However, the ΔE values and the examiners' scores were within the clinically acceptable range for both shade guides.

Shade Guide Optimization-A Novel Shade Arrangement Principle for both Ceramic and Composite Shade Guides When Identifying Composite Test Objects

The most widely used shade guide for composite materials is made of ceramic and arranged according to a non-proven method. There is a need for a composite shade guide using a scientifically based arrangement principle. To compare the shade tab arrangement of the Vitapan Classical shade guide and an individually made composite shade guide using both the originally proposed arrangement principle and arranged according to ΔE2000 values with hue group division. An individual composite shade guide made from Filtek Supreme XT body colors was compared to the Vitapan Classical shade guide. Twenty-five students matched color samples made from Filtek Supreme XT body colors using the two shade guides arranged after the two proposed principles--four shade guides in total. Age, sequence, gender, time, and number of correct matches were recorded. The proposed visually optimal composite shade guide was both fastest and had the highest number of correct matches. Gender was significantly associated with time used for color sampling but not regarding the number of correct shade matches. A composite shade guide is superior compared to the ceramic Vitapan Classical guide when using composite test objects. A rearrangement of the shade guide according to hue, subdivided according to ΔE2000, significantly reduces the time needed to take a color sample and increases the number of correct shade matches. Total color difference in relation to the lightest tab with hue group division is recommended as a possible and universally applicable mode of tab arrangement in dental color standards. Moreover, a shade guide made of the composite materials itself is to be preferred as both a faster and more accurate method of determining color.

Experimental investigations into visual and electronic tooth color measurement

The present study aimed to examine the validity of the visual color assessment and an electronic tooth color measurement system by means of Shade Inspector™ in comparison with a gold standard. Additionally, reproducibility of electronic measurements was demonstrated by means of two reference systems. Ceramic specimens of two thicknesses (h=1.6 mm, h=2.6 mm) were used. Three experienced dental technicians using the VITAPAN Classical(®) color scale carried out all visual tests. Validity of the visual assessment and the electronic measurements was confirmed separately for both thicknesses by means of lightness and hue of the VITAPAN Classical(®) color scale. Reproducibility of electronic measurements was confirmed by means of the VITAPAN Classical(®) and 3D-Master(®). The 3D-Master(®) data were calculated according to lightness, hue and chroma. Intraclass correlation coefficient (ICC) was used in assessing validity/reproducibility for lightness and chroma, Kappa statistics were used for hue. A level ≥0.75 was pre-established for ICC and ≥0.60 for the Kappa index. RESULTS OF VISUAL COLOR ASSESSMENT: Validity for lightness was good for both thicknesses; agreement rates for hue were inconsistent. ELECTRONIC MEASUREMENT: Validity for lightness was fair to good, hue values were below 0.60. Reproducibility of lightness was good to very good for both reference systems. Hue values (VITAPAN Classical(®)) for 1.6 mm test specimens were upside, for 2.6 mm below 0.60, Kappa values for 3D-Master(®) were ≥0.60 for all measurements, reproducibility of chroma was very good. Validity was better for visual than for electronic color assessment. Reproducibility of the electronic device by means of the Shade Inspector™ was given for the VITAPAN Classical(®) and 3D-Master(®) systems.

Clinical assessment of whitening efficacy and safety of in-office tooth whitening system containing 15% hydrogen peroxide with or without light activation

Objectives: This clinical study evaluated the effect of light activation on the whitening efficacy and safety of in-office bleaching system containing 15% hydrogen peroxide gel. Materials and Methods: Thirty-three volunteers were randomly treated with (n = 17, experimental group) or without light activation (n = 16, control group), using Zoom2 white gel (15% , Discus Dental) for a total treatment time of 45 min. Visual and instrumental color measurements were obtained using Vitapan Classical shade guide and Shadepilot (DeguDent) at screening test, after bleaching, and 1 month and 3 month after bleaching. Data were analyzed using t-test, repeated measure ANOVA, and chi-squared test. Results: Zoom2 white gel produced significant shade changes in both experimental and control group when pre-treatment shade was compared with that after bleaching. However, shade difference between two groups was not statistically significant (p > 0.05). Tooth shade relapse was not detected at 3 months after bleaching. The incidence of transient tooth sensitivity was 39.4%, with being no differences between two groups. Conclusions: The application of light activation with Zoom2 white gel system neither achieved additional whitening effects nor showed more detrimental influences.

Digital Computer Matching of Tooth Color

This study aimed to determine the validity of the digital photocolorimetric (PCM) method in matching the color of human teeth. First, two Vitapan Classical shade guides, each containing 16 shade guide teeth, were visually shade matched, and digital photographs of each three pair of shade guide teeth were taken in a color matching booth. Secondly, visual shade matching of the upper central incisors of 48 subjects was performed by two prosthodontists independently in a chair, using the Vitapan Classical shade guide. The three closest shade guide teeth were visually selected and ranked in order of preference, for which digital photographs were taken under ceiling daylight-corrected fluorescent lighting. All digital images were analyzed on a computer screen using software to calculate the color difference between the reference tooth and other teeth in the same digital image. The percent color matching for the shade guide teeth and human teeth was 88% and 75%, respectively. There was no statistically significant difference in matching the tooth color between the shade guide teeth and human teeth. The digital PCM method is valid for the range of human teeth based on the Vitapan Classical shade guide. This method enhances communication with the laboratory personnel in matching the tooth color.

Teaching of color in predoctoral and postdoctoral dental education in 2009

Objectives The goal of the study was to determine the current status of the teaching of color in dental education at both the predoctoral (Pre-D) and postdoctoral (Post-D) levels. Methods A cross-sectional web-based survey, containing 27 multiple choice, multiple best and single best answers was created. Upon receiving the administrative approval, dental faculty involved in the teaching of color to Pre-D or Post-D dental students from around the world ( N = 205), were administered a survey. Statistical analysis of differences between Pre-D and Post-D was performed using Chi-square test ( α = 0.05). Results A total of 130 responses were received (response rate 63.4%); there were 70 responses from North America, 40 from Europe, 10 from South America, nine from Asia and one from Africa. A course on “color” or “color in dentistry” was included in the dental curriculum of 80% of Pre-D programs and 82% of Post-D programs. The number of hours dedicated to color-related topics was 4.0 ± 2.4 for Pre-D and 5.5 ± 2.9 for Post-D, respectively ( p < 0.01). Topics associated with tooth color, shade matching method, tooth whitening, and teaching of appearance parameters other than color, were frequently taught. Conclusions Significant differences were recorded between the number of hours dedicated to teaching of color at predoctoral and postdoctoral level. The same is true for the prosthodontics and restorative courses, teaching on negative after images; color rendering index, Bleachedguide 3D-Master shade guide, digital camera and lens selection, composite resins, and maxillofacial prosthetic materials. Except for the restorative courses and composite resins, significantly higher results were recorded for Post-D programs. Vitapan Classical and 3D-Master were the most frequently taught shade guides.

Color change of vital teeth exposed to bleaching performed with and without supplementary light

Objectives The aim of this clinical study was to evaluate tooth color change after exposure to 25% hydrogen peroxide in-office tooth whitening system, with and without supplementary light exposure. Methods Twenty subjects were treated with two separate 45-min exposures of bleach, with and without light using an opposing-arch design. Visual and instrumental color measurements were obtained from eighty teeth before bleaching and seven days after treatment using two different shade guides, Vitapan Classical (VC), Vita Bleachedguide 3D-Master (BG) and an intraoral spectrophotometer. Data were analyzed using ANOVA, paired t-test, and Wilcoxon signed rank tests at the 0.05 level of significance. Results Instrumental method revealed significant difference in color between treatment with light ( Δ E a b * = 6.0 ) and without light ( Δ E a b * = 4.7 ) after seven days ( p < 0.05). No differences were visually detected between treatment with light and without light using the VC ( p = 0.56). However, a significant difference was recorded using the BG ( p < 0.01). Instrumental measurements of color change were in better accordance with visual findings using the BG guide ( R 2 = 0.60) rather than the VC ( R 2 = 0.20). Conclusions Within the limitations of this study, the treatment with supplementary light showed significantly greater bleaching-dependent changes in color compared to treatment without light when assessed using instrumental methods. The same was determined for the visual method with Vita Bleachedguide 3D-Master. No significant difference in color change with respect to light exposure was detected for the Vitapan Classical.

Reliability and accuracy of four dental shade-matching devices

There are several electronic shade-matching instruments available for clinical use, but the reliability and accuracy of these instruments have not been thoroughly investigated. The purpose of this in vitro study was to evaluate the reliability and accuracy of 4 dental shade-matching instruments in a standardized environment. Four shade-matching devices were tested: SpectroShade, ShadeVision, VITA Easyshade, and ShadeScan. Color measurements were made of 3 commercial shade guides (Vitapan Classical, Vitapan 3D-Master, and Chromascop). Shade tabs were placed in the middle of a gingival matrix (Shofu GUMY) with shade tabs of the same nominal shade from additional shade guides placed on both sides. Measurements were made of the central region of the shade tab positioned inside a black box. For the reliability assessment, each shade tab from each of the 3 shade guide types was measured 10 times. For the accuracy assessment, each shade tab from 10 guides of each of the 3 types evaluated was measured once. Differences in reliability and accuracy were evaluated using the Standard Normal z test (2 sided) (alpha=.05) with Bonferroni correction. Reliability of devices was as follows: ShadeVision, 99.0%; SpectroShade, 96.9%; VITA Easyshade, 96.4%; and ShadeScan, 87.4%. A significant difference in reliability was found between ShadeVision and ShadeScan (P=.008). All other comparisons showed similar reliability. Accuracy of devices was as follows: VITA Easyshade, 92.6%; ShadeVision, 84.8%; SpectroShade, 80.2%; and ShadeScan, 66.8%. Significant differences in accuracy were found between all device pairs (P<.001) for all comparisons except for SpectroShade versus ShadeVision (P=.033). Most devices had similar high reliability (over 96%), indicating predictable shade values from repeated measurements. However, there was more variability in accuracy among devices (67-93%), and differences in accuracy were seen with most device comparisons.

Performance assessment of dental shade guides

Objectives The goal of this study was to evaluate influence of different shade guides and respective shade matching methods on shade matching results and to analyze user satisfaction with these products and methods. Methods Eighty-eight pre-doctoral dental students completed the study. The color of four target shade tabs was matched using Toothguide 3D-Master (TG), Vitapan Classical (VC), and the prototype of Linearguide 3D-Master (LG). Shade matching was performed using color-corrected light source and 0/45° optical geometry. An intra-oral spectrophotometer was used for color measurements of target tabs and shade guide tabs. Results for the first 10 best matching shade guide tabs were expressed as ranks (best match – 10 points to 10th match – 1 point). Participants also performed subjective evaluation of three shade guides/tab arrangements. Descriptive statistics were calculated. T-test and Wilcoxon signed rank test were used for statistical analysis of the data ( α = 0.05). Results The best shade matching results were achieved using LG, followed by VC and TG, and the ranks were 9.1 ± 1.2, 8.8 ± 1.9 and 8.4 ± 2.8. Differences in Δ E* values for the first 10 matches between TG/LG (4.5 ± 1.8) and VC (6.2 ± 2.2) were found to be statistically significant ( p < 0.001). Subjective evaluation revealed significant advantage of LG compared to TG and VC. Conclusions Linearguide 3D-Master enabled better shade matching results compared to Toothguide 3D-Master ( p < 0.05). Both 3D-Master shade guides exhibited significantly smaller Δ E* values for the first 10 matches compared to Vitapan Classical ( p < 0.001). Linearguide 3D-Master was superior in a subjective evaluation compared to Toothguide 3D-Master and Vitapan Classical ( p < 0.001).

Colour correspondence of a ceramic system in two different shade guides

Objectives The aim of this study was to test by means of a clinical spectrophotometer the ability of a ceramic system to correctly reproduce the selected shade with reference to two available shade guides. Methods One shade for each guide of Vita Omega 900 ceramic system (Vita Zahnfabrik, Germany) was selected: A3 for the system based on Vitapan Classical; 2M3 for the system based on Vitapan 3D Master. Fifteen discs were fabricated for each ceramic using a proprietary steel mould that allowed to control the thickness of each layer. The total thickness of the specimen was 1.6 mm. The thickness of the metal base disc was 0.3 mm, while opaque was layered in 0.15 mm. Dentin opaque (0.25–0.45 mm), dentin (0.5–0.7 mm), and enamel (0.1–0.3 mm) were then layered following manufacturer's patterns. Each layer thickness was checked after firing. Easyshade (Vita Zahnfabrik, Germany) clinical spectrophotometer was used for colour comparison. “Restoration” mode was selected using A3 and 2M3 shades as comparison. The obtained Δ E values were statistically analyzed with the Two-Way Analysis of Variance and the Tukey Test. Results A closer colour correspondence resulted for the ceramic based on Vitapan 3D Master (Δ E = 1.80 ± 0.42) than for Omega 900 in Vitapan Classical (Δ E = 2.94 ± 0.12) ( p < 0.001). Conclusions The shade matching ability of the VITA 3D-Master Tooth Guide was found to be more reliable than that of the VITA Classical Shade Guide for Omega 900.

Comparison of visual shade determination and an intra‐oral dental colourimeter

The choice of correct tooth shade for the fabrication of a restoration remains a challenge, even for experienced clinicians. The aim of this research was to evaluate and compare the precision of two different shade determination methods in terms of repeatability. Maxillary right central incisor of 10 patients was evaluated visually with the use of Vitapan Classical shade guide by five observers and instrumentally with the Vitapan classical shade guide values of ShadeEye NCC intra-oral colourimeter three times consecutively. The in vivo repeatability of methods were analysed with the spectrophotometric L*, a*, b* values of the shade guide (Vitapan Classical). Within the limitations of this study, the repeatability of instrumental (intra-oral dental colourimeter) and visual shade determinations were acceptable.

Development of a Model Shade Guide for Primary Teeth

Large disparities in colour ranges and distribution between primary and permanent teeth make shade guides for permanent teeth unsuitable for primary teeth applications. The aim of the study was to develop a model shade guide for primary teeth. The Vita Easyshade intraoral spectrophotometer was used to determine colour at the middle labial/buccal third surface of 612 primary teeth of 102 patients. Model shade guides, containing 1-16 tabs, were designed in CIELAB (DeltaE*) and CIEDE2000 (DeltaE') colour difference formulae using nonlinear optimization. The coverage error (DeltaECOV) was calculated as the mean of minimal colour differences between each of primary teeth and the "closest" shade tab. Results were analyzed using descriptive and analytical statistics. The coverage error of Vitapan Classical shade guide applied to the primary teeth evaluated was 4.2 (SD +/- 1.8). DeltaE*COV and DeltaE'COV values for model shade guides with 16 tabs were 1.8 and 1.3, respectively. The CIELAB coverage error of the model shade guide containing two tabs outperformed DeltaE*COV of Vitapan Classical. As compared with Vitapan Classical shade guide, significantly smaller coverage error was obtained in the model shade guide with the same number of tabs, designed via constrained nonlinear optimization.

New shade guide for tooth whitening monitoring: Visual assessment

Shade guides currently used to monitor tooth bleaching lack logical order, uniform color distribution, and light shade tabs, thus, limiting the design of bleaching studies and diminishing the validity of obtained results. The purpose of this study was to perform a visual evaluation of a new shade guide designed primarily for monitoring tooth whitening and to compare this shade guide with 2 commercial shade guides. Tab arrangement of 3 shade guides (prototype of new VITA Bleachedguide 3D-Master (BG), value scale of Vitapan Classical (VC), and color-ordered Trubyte Bioform porcelain shade guide (TB)) was evaluated. The tabs from each shade guide, one at a time, were scattered and visually reordered from the lightest to the darkest by 15 observers under controlled conditions of a viewing booth. Visual ranking was compared to manufacturer-suggested ranking. Interobserver repeatability was compared using the Mann-Whitney U test (alpha=.05). All observers responded to a questionnaire grading the 3 shade guides using a Likert scale (1, strongly disagree, to 5, strongly agree). The Kolmogorov-Smirnov z-test (alpha=.05) was used to process the results obtained in the questionnaire Visually determined BG order was found to be identical to the order given by the manufacturer. This was not the case with the 2 other products: visual and manufacturers' order were identical for 7 of 16 VC tabs and 9 of 24 TB tabs. Interobserver repeatability for BG was significantly higher (P<.001) as compared to corresponding values recorded for VC and TB, whereas no statistically significant difference in interobserver repeatability between VC and TB was observed. Visually determined lightest to darkest order was identical to the suggested manufacturer order only for VITA Bleachedguide 3D-Master. The same shade guide was also superior based on the scores given in the questionnaire. These findings support the use of the new VITA Bleachedguide 3D-Master for monitoring tooth whitening.

New Shade Guide for Evaluation of Tooth Whitening—Colorimetric Study

Available shade guides lack colorimetric uniformity, which compromises the validity of visual evaluation of tooth whitening efficacy. The objective of this study was to perform a colorimetric analysis of a new shade guide designed primarily for the visual evaluation of tooth whitening efficacy and to compare this shade guide with two commercial shade guides. Color ranges and color distribution of three shade guides (prototype of the new Vita Bleachedguide 3D-Master [BG, Vita Zahnfabrik, Bad Säckingen, Germany], value scale of Vitapan Classical [VC, Vita], and color-ordered Trubyte Bioform porcelain shade guide [TB, Dentsply International, York, PA, USA]) were analyzed (N=3). A circular area (d=1.7 mm) on the middle of the labial surface of the tab, excluding the cervical portion, was measured with a spectroradiometer (D65, 2). Whiteness and yellowness indices were computed. Data were analyzed by analysis of variance and Fisher's PLSD test at a 0.05 level of significance. The range of color difference (DeltaE*) from the lightest to the darkest tab was 33.8 (BG), 17.1 (VC), and 23.2 (TB). Mean values of DeltaE* among pairs of adjacent tabs were 3.0 (BG), 4.2 (VC), and 3.3 (TB). BG exhibited the highest R2 values between color coordinate pairs and between whiteness and yellowness indices with the respective color coordinates. BG exhibited the widest color range and had the most consistent color distribution as compared with the two commercial products. Extension of the lightness range of BG toward higher L* values (bleach shades) was confirmed. A dental shade guide that is colorimetrically uniform might increase the reliability of visual comparisons of tooth whitening efficacy, whereas the inclusion of realistic bleaching shades in the shade guide will complement contemporary esthetic dentistry.