Proposal for a gingival shade guide based on in vivo spectrophotometric measurements

PURPOSE: The purpose of this study was to propose and assess a shade guide for pink gingival aesthetics using a Spanish population sample. MATERIALS AND METHODS: The L*, C*, h, a* and b* coordinates of 259 participants were measured using a spectrophotometer in 3 standardized points along the attached gingiva of the maxillary central incisors. A hierarchical clustering analysis was applied to obtain separate solutions regarding the number of shade tabs. For each of the solutions obtained, color differences (ΔE*) were calculated using the CIELab and CIEDE2000 formulas, and the proposed shade guide was selected considering (1) the color differences between tabs and (2) the coverage error of each of the solutions. RESULTS: The proposed shade guide consisted of 8 gingival shade tabs and achieved CIELab and CIEDE2000 coverage errors of less than the respective 50:50% acceptability thresholds (ΔE*=4.6 units and ΔE₀₀=4.1). The coordinates for the various gingival shade tabs were as follows: Tab 1: L*43.3, a*21.9, b*12.3 (1.6); Tab 2: L*42.9, a*34.1, b*19.1; Tab 3: L*46.5, a*25.8, b*10.9; Tab 4: L*46.5, a*27.3, b*15.1; Tab 5: L*49.6, a*23.5, b*16.8; Tab 6: L*51.5, a*19.7, b*13.6; Tab 7: L*55.9, a*22.0, b* 15.0; and Tab 8: L*56.0, a*19.9, b*18.8. CONCLUSION: The CIELab and CIEDE2000 coverage errors for the 8 shade tabs of the proposed gingival shade guide were significantly lower than those of other guides. Therefore, despite the limitations of this study, the proposed guide is more appropriate for matching gingival shade in the Spanish general population.

Clinical evaluation of color change and tooth sensitivity with in-office and home bleaching treatments

Among the number of vital bleaching techniques currently available to the clinicians, home bleaching and in-office bleaching are widely used in dental practice. Aim and Objectives: The aim of this in vivo study was to compare the clinical performance, durability, and related tooth sensitivity with two vital bleaching procedures (in-office and at-home bleaching), in a split-mouth design. Patients and Methods: Thirty adult participants having teeth shade mean of A2 or darker were selected for the study. One-half of the maxillary arch of each patient received in-office bleaching with 35% hydrogen peroxide gel, and the other half received 16% carbamide peroxide night guard bleaching. Shade evaluation was done with shade guide and spectrophotometer at 1, 2, 3, and 4 week intervals during bleaching and postoperatively at 3 and 6 month intervals. Tooth sensitivity was recorded using the visual analog scale during the experimental period. Statistical Analysis: Collected data of color and sensitivity readings were subjected to statistical analysis using SPSS/PC version 20 software. Intergroup comparison through unpaired t-test and within the groups using paired t-test was done. Results: At-home and in-office bleaching procedures are equally effective in producing tooth whitening. Color evaluation after 3 and 6 months showed more color decline for in-office bleaching procedure. For sensitivity parameter also, in-office procedure recorded higher sensitivity compared to home bleaching (P < 0.05). Conclusion: Both the bleaching procedures are equally effective in producing tooth whitening. In-office bleaching recorded higher levels of tooth sensitivity and greater color rebound than home bleaching.

Comparative study on the shade matching performance of dental students under D55 and D65 light sources conditions / 华西口腔医学杂志

OBJECTIVE@#This study aimed to compare the effect of D55 and D65 light sources on the visual colorimetry performance of dental students by using a homemade light-source shelf.@*METHODS@#Two Vitapan 3D-Master shade guides were randomly selected. One set was used as shade guides. Ten commonly used shade tabs of 2L2.5, 2M2, 2R2.5, 3M2, 3R2.5, 3L1.5, 3R1.5, 3L2.5, 4R1.5, and 4L1.5 were selected from the other set with covered value marks and numbered from 1 to 10. After the colorimetric training, 49 undergraduate dental students were randomly divided into two groups. Each student randomly selected two of the 10 shade tabs, and the colors were subsequently matched under D65 and D55 light sources from a distance of approximately 40 cm. The average color difference (ΔE) between the color selected by each participant and the actual color of shade tabs was calculated. Paired t test was used for statistical analysis.@*RESULTS@#The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D55 light source varied from 0 to 6.540. The average value was 2.501. The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D65 light source varied from 0 to 6.610. The average value was 2.530. No statistically significant difference was observed between the results under the two light sources (P=0.921).@*CONCLUSIONS@#Both D55 and D65 daylight lamps can be used for daily dental colorimetry. These two different color temperatures showed no significant difference.

Shade selection of primary maxillary anterior teeth in children using Vitapan classical shade guide.

Aim: The purpose of this study was to determine the closest matching shade for primary maxillary anterior teeth from the most widely used Vitapan classical shade guide available for permanent teeth. Materials and Methods: A total of 313 children aged between 3 and 5 years were evaluated. Vitapan classical shade guide was used to determine the shade of six primary maxillary anterior teeth. Scores obtained were noted down in a scoring sheet and values were tabulated. Data collected were tabulated and statistically analyzed using Pearson Chi‑square test. Results: A1 was found to be the closest matching shade for primary maxillary anterior teeth. D3 was found to be the least prevalent shade for primary maxillary anterior teeth. There was no statistical significant difference in the shades among teeth of same quadrant (p > 0.05) and also between teeth of right and left quadrants (p > 0.05), respectively. Conclusion: A1 shade of Vitapan classical shade guide is the most prevalent shade for primary maxillary anterior teeth and can be satisfactorily reproduced to all primary maxillary anterior teeth in general.

Analysis of vita shade guide with spectrophotometer under different color measurement conditions / 第二军医大学学报

Objective To compare the accuracy of spectrophotometer under different color measurement conditions, so as to provide evidence for clinical color measurement. Methods Spectrophotometer was used to obtain the chromatic value L*, a* and b*(L*:Lightness; a*:Saturation on the red and green axile; b*:Saturation on the yellow and blue axile) of all color pieces in the medium 1/3 of vita classical shade guide under the natural light, incandescent lamp and dark room; the values of chromatism were calculated under different color measurement conditions, and the results were fed to statistical software for analysis. Results The L*, a* and b* values were not significantly different under natural light, incandescent lamp and dark room. The composition ratios of ΔE <1.5 NBS for the natural light and incandescent light, natural light and dark room, incandescent lamp and dark room were 87.50%, 100%, and 93.75%, respectively. Conclusion The measurement accuracy of CM-700d spectrophotometer is high and the environment light has slight effe0ct on the accuracy. The chromatism values of shade guide measured in the dark room is the most true ones, so dark room is recommended for CM-700d spectrophotomete.

Vitapan 3D-master shade guide showed no fluorescence emission.

Objectives: To determine the fluorescence property of Vitapan 3D-Master shade guide tabs with a spectrophotometer. Materials and Methods: Fluorescence property of 29 shade tabs, in both of original and ground-to-flat forms, was determined by a reflection spectrophotometer. Color difference (ΔE*ab-FL) by the inclusion and exclusion of the UV component of a standard daylight simulator (CIE standard illuminant D65) was calculated to determine the fluorescence color change. Fluorescence peak was expressed as the difference in spectral reflectance values by the UV component. Results and Conclusion: ΔE *ab-FL values were in the range of 0.2 to 2.7 (mean: 1.2±0.6) for the original and 0.5 to 1.6 (mean: 0.9±0.1) for the ground-to-flat tabs, which was significantly different based on paired t-test (p<0.05); however, fluorescence peak was not detected in all the shade tabs. Therefore, fluorescence property of Vitapan 3D-Master shade guide should be modified to have similarfluorescence property of natural teeth and corresponding restorative materials.

The evaluation of clinical efficacy and longevity of home bleaching without combined application of In-office bleaching / 대한치과보존학회지

OBJECTIVES: The purpose of this study was to evaluate the whitening efficacy and longevity of home bleaching. MATERIALS AND METHODS: A total of 28 patients were divided into either experimental group (Opalescence F; 15% carbamide peroxide) or control group randomly. The patients in experimental group were instructed to wear individual trays applied with bleaching gel for 2 hours a day for 4 weeks. Any treatments weren't applied to the patients in control group. The color measurements of central incisors, lateral incisors & canines of upper and lower arch were recorded at base line, immediately after the finishment of treatmemt (4 weeks), 8 weeks and 12 weeks using Colorimeter (Chroma Meter, 2600d Konica Minolta co.) and Vitapan classical shade guide (Vita Zahnfabrik). RESULTS: A significantly stronger color change was observed for overall teeth samples in experimental group immediately after treatment (at 4 weeks) compared to ones in control group (p < 0.05). There was also a significant difference between baseline and 8 weeks or 12 weeks separately though color rebouncing phenomenon occurred as time went by (p < 0.05). CONCLUSIONS: The clinical effecacy and longevity of home bleaching without combined application of in-office bleaching was observed through this experiment.

Evaluation of shade guide using digital shade analysis system / 대한치과보철학회지

STATEMENT OF PROBLEM: There are two methods of color choice for the esthetic restoration. One is visual shade matching which draws a comparison between shade guide and teeth in dentist's own eye and the other is using a digital shade analysis system recently introduced. Although the visual shade matching has a lot of problems, decision of color by this visual shade matching and the ways of expression for the decided color are still applicable to clinical dentistry. PURPOSE: This study is designed to investigate shade guides used in the dental clinics and laboratories have the same value using ShadeEye-NCC(R). dental chroma meter (Shofu Inc., Kyoto, Japan) using shade guide are evaluated. MATERIAL AND METHODS: At the first experiment, eight Vita Lumin Vacuum shade guides (Vident Inc., California, USA) were collected from the dental clinics. A1 and B1 shade tabs are chosen and the colors are analyzed five times each in both tooth and porcelain modes by digital shade analysis system, ShadeEye-NCC(R). In the second experiment, twelve Vita shade guides using practically in the dental clinics and laboratories were collected and also A1 and B1 shade tabs are chosen and the colors of A1 and B1 are analyzed one time each in both tooth and porcelain modes by ShadeEye-NCC(R). RESULTS AND CONCLUSION: There were significant differences among eight shade guides in terms of shade (chroma), value and hue in both of A1 and B1 (P < .05). Shade guides using in present both dental clinics and laboratories did not show significant differences, except A1 in the porcelain mode, it showed significant differences (P < .05) in the shade even though the shade tab has the same name.

Shade comparative analysis of natural tooth measured by visual and spectrophotometric methods / 대한치과보철학회지

STATEMENT OF PROBLEM: A clinically successful color match is one of the important factor to get an esthetic dental restoration. Dental shade guides are commonly used to evaluate tooth color in restorative procedure. But numerous reports have indicated that common shade guides do not provide sufficient spectral coverage of the natural tooth colors. To address issues associated with the shade guide, distinct avenues have been pursued objective spectrophotometric / colorimetric assessment. PURPOSE: This study compared the accuracy of tooth color selection of spectrophotometer with that of human visual determination. Three main factors were investigated, namely, the effect of light, the individual variation and the experience of the observer. MATERIAL AND METHODS: At the first experiment, on ten patients, one operator independently selected the best matching shade to the unrestored maxillary central incisor, using a Vita Classical Shade Guide in the morning, at noon and in the afternoon. The same teeth were measured by means of a reflectance spectrophotometer. At the second experiment, on ten patients, ten operators (5 experts, 5 novices) selected and measured by the same method above at noon. At the third experiment, the results of the second experiment were divided into two groups, expert and novice, and analyzed. RESULTS: 1. There was significant difference between visual and spectrophotometric assessment (mean delta E values) in experiment 1, 2, 3 (p < .05). 2. There was no significant difference between experts and novices group, when comparing with each visual and spectrophotometric assessment (mean delta E values). CONCLUSION: Spectrophotometer could be used to analyze the shade of natural tooth objectively. Thereby, this method offers the potential tominimize considerably the need for corrections or even remakesafter intraoral try-in of restoration. Furthermore, to achieve its advantage, both the shade-matching environment and communication between dentist and technician should be optimized with use of visual and instrumental shade-matching systems.

Shade perception ability among different dental personnel / 대한치과보철학회지

Statement of problem: Many factors influence shade determination in clinical practice and shade matching is highly affected by the viewing conditions. Purpose: This study investigated the differences in shade perception among distinct groups of dental personnel (10 prosthodontists, 10 general practitioners, 10 last-year dental students and 10 dental technicians). Material and method: Four groups of dental personnel were investigated. They were tested to eliminate color blindness. To compare shade selection ability, they were asked to match four test tabs of shades A3, B2, C2 and D4 (VITAPAN. Classical shade guide. The identification codes of the shade tabs were masked to prevent shade memory.) against another full set of VITAPAN. Classical shade guide under similar lighting conditions. Shade selections were randomly repeated five times every week and then the repeatability between dental personnel was evaluated. To compare value perception ability, they were asked to arrange randomly selected five test tabs (B1, A2, D2, C3, A4) in descending order from the brightest to the darkest. To compare hue determination ability, they were asked to divide selected eight test tabs (A2, A3, B2, B3, C2, C3, D2, D3) into four groups by manufacturer as follows: Group A-Reddish brown, Group B-Reddish yellow, Group C-Grey, Group D-Reddish grey. Results and conclusion: The obtained results were as follows: 1. For the value perception ability and hue determination ability, there was no significant difference among 4 groups: prosthodontists, general practitioners, dental students, dental technicians(P>.05). 2. For shade selection ability, the prosthodontists and dental technicians were significantly higher than dental students(P<.05). 3. The repeatability of selected shade in the dental technicians was significantly higher than that of general practitioners and dental students(P<.05). 4. The prosthodontists and dental technicians had significantly higher selection ability than dental students for shade B2(P<.05).

Influence of the shade guide design on color matching / 대한치과보존학회지

This study was conducted in order to assess whether the form of the shade guide affects in deciding the color of the teeth using the shade guide. Eight shade light cured composite resins (Esthet-X, Dentsply, Milford, USA) were used in this study. Shade guides including the model of maxillary central incisors, teeth-form shade guide, doughnut form shade guide, and shade guide with perforated gray shield were prepared with eight shade composite resins and provided the codes randomly. After arranging the models of teeth, 19 dentists working at the clinic of the Dentistry of Chonnam University Hospital and 65 students of college of dentistry, Chonnnam University selected the shade guides corresponding to the color of each tooth on the gray board under the D65 standard illuminant. B1 shade showed highest accuracy of about 95% among all shade guides of 3 forms applied to the test and regardless of observer, tooth form shade guide showed the highest accuracy (p < 0.05), and the doughnut form showed the lowest accuracy (p < 0.05). At the time of deciding on the color of the teeth using the shade guides as a result of above, the forms of the shade guides can affect the accuracy, and it suggests that the development of the diversified forms of shade guides, which may obtain more accurate results, is required.

Study of reliability of tooth color measuring by digital photographic system / 实用口腔医学杂志

Objective:To investigate the reliability of tooth color-measuring by using digital cameras.Methods: 3D-Master shade guide system was measured by Canon EOS D60,CRAIC QDI2000 micropectrophotometer and ShadeEye-NCC directly.The data collected from the three methods were analyzed statistically to evaluate the reliability of the data measured by digital cameras.Results:There was no significant difference between the data measured by digital cameras and ShadeEye-NCC statistically;while that existed between the parameters of L* collected by digital cameras and microspectrophotometer were obviously co-related(P

Effects of cerium oxide content on the color of alumina-glass composite / 实用口腔医学杂志

objective: To investigate the effects of cerium oxide content on the color of alumina glass composite. Methods: Infiltration glass powder with different content of cerium oxide (1%～4%) were fabricated. Alumina glass composite was prepared by infiltrating molten glass into presintered alumina block at 1 250 ℃ for 2 h, and the color of the alumina glass composite were measured with Minolta chromatic instrument(CR 321) . For comparison, the color of VITA In Ceram alumina technical shade guide was recorded too. Results: After infiltration, the b * range of the alumina glass composite was in accord with that of the shade guide. With the increasing content of the cerium oxide, a *, b * and chroma increased, L * decreased, the hue of the alumina glass composite shifted from yellow green to yellow red. Conclusion: Cerium oxide may effectively enhance b * of the alumina glass composite, but its ability of reducing L * and enhancing a * is weak.

Color difference between the restoration materials in anterior teeth and the shade guide / 实用口腔医学杂志

Objective:To observe the consistence of the color and optical parameters of metal-ceramic, all-ceramic and composite resin with Vita Classical shade guides. Methods:Specimens of VITA VMK95 metal-ceramic, In-Ceram all-ceramic and Artglass composite resin according to the same area with Vita Classical shade guide were made respectively. ?E_ ab ,L,a,b between specimens and shade guide were calculated. Results:The mean ?E between shade guide and all-ceramic or composite resin was less than 3 NBS. The mean ?E between shade guide and metal-ceramic material was 13.78 NBS, the significant difference could be identified by visual determination (P

Comparative study on the shade of two kinds of Vita shade-guide / 实用口腔医学杂志

Objective: To measure and compare the color of a new and a conventional Vita shade guide(VITAPAN 3D-Master and LUMIN RVACUUM-Farbskala) in order to provide the references for clinical application.Methods: Color in the two shade guides was measured with Minolta colorimeter CR-321 under the light of D 65 and reported in CIE1976L*a*b* color system. Each tab was detected 3 times in the same dimensions at the middle facial surface. Mean values were calculated as the shade of the tab.Results: The range of color value in VITAPAN 3D-Master was larger than that in LUMIN R VACUUM-Farbaskala because the lower value tab was added. The distrbution of a* deviated to the red color , while the green color was relatively deficient. The yellow color could cover the color space of Chinese teeth, and the blue was not enough, although the distribution of b* was enlarged. The tabs of the two shade guides did not match with each other. Only a few tabs could not tell in shade by naked eyes. Conclusion: VITAPAN 3D -Master shade guide can not cover the color of Chinese teeth although it has 10 tabs added and color space enlarged.

Computer analysis of the color in ShoFu colormeter plate / 实用口腔医学杂志

Objective: To study the color in ShoFu colormeter plate. Methods: The values of color degree of the cervical, body and incisal end of various teeth in the ShoFu colormeter plate were measured by digital camera and analyzed by computer using CIE1976L*a*b* system and JISZ8722 standard. Results: In ShoFu plate the brightness in the cervical, body and incisal end of various teeth changed following a certain rule, the brightness in group R and VR were higher than that in group A. While the values of color degree in other groups changed without any rule. Conclusion: The digital camera and computer may be used in dental color study.

Comparison of color level among Vita,Shofu and Dentsply shade guide / 实用口腔医学杂志

Objective:To compare color level among Vita,Shofu and Dentsply shade guide. Methods:Vita,Shofu and Dentsply shade guide were scanned into a computer and saved as BMP pictures. L *, a * and b * values of the color of the images were measured by Photoshop. Results:There was same trend of variation in color of the shade guides, but the maximum and minimum of L *, a * and b * in those shade guides were different. Conclusion: For matching color accurately, one shade guide can not be used to replace the other one in clinical application.

Analysis of chromatic value of Vitapan 3D-Master shade guide / 实用口腔医学杂志

Objective; To study the chromatic distribution of the chromatic value of Vitapan 3D- Master shade guide in color space. Methods: The color space of.Vitapan 3D-Master shade guide was measured and analyzed with CIE-1976-L* a* b. system and MINOLTA chromatic instrument (CR-321 ) under D65 standard source. Results: 26 shades of Vitapan 3D-Master could be divided into 5 groups according to the 3-dimensional layers. Inside the 2nd, 3th and 4th group, 6 shades distributed as equidistant ring circling M2 shade because their hue and chroma were different. The hue of L1. 5 and L2. 5 deflected to yellow, R1.5 and R2. 5 to red,that of M1-3 was intervenient. Conclusion: Vitapan 3D-Master shade guide is equidistant in color space and can be used more effeciently than Vitapan classical. Its chromatic value distribution perfectly and evenly covered color region of nature tooth.