• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.1-11
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• 2009

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.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.81-93
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• 2013

The objectives were to evaluate the accuracy of shade selection by human visual system(VS) and 2 different colorimeters ($ShadeEye^{(R)}$(SE) and Shadepilot (SP)). Maxillary anterior teeth of 30 volunteers which had no caries or restorations were included in the study. Firstly, the accordance in shade selection by 3 dentists and 2 colorimeters was investigated. Secondly, the color of the teeth were measured by 1 observer's naked eye and 2 colorimeters under different illumination conditions (Sunny versus cloudy day). Additionally testing of inter-observer variability selected colors by 2 novice and 2 experienced dentists were compared. For comparing visual and 2 different colorimeters, SP(60%) showed significantly highest rate of accordance than the visual (23.3%) or SE (16.7%) and lowest mean ${\Delta}E$ ($2.62{\pm}0.74$ versus $3.83{\pm}1.38$;SE or $4.04{\pm}1.61$;VS)(p<0.001). If accuracy of shade selection were measured using VS, the mean ${\Delta}E$ value of cloudy day was higher than that of sunny day ($4.35{\pm}1.70$ versus $3.53{\pm}1.31$; p<0.001). There were no significant difference of the mean ${\Delta}E$ value between sunny and cloudy day in both SE and SP. Inter- observer repeatability was higher in 2 experienced group (73.3%) than novice group (36.7%). The mean ${\Delta}E$ of experienced group was lower than that of novice group ($3.60{\pm}1.47$ versus $4.70{\pm}1.67$; p<0.001). Colorimeters (SE or SP) is more accurate and more reproducible compared with human shade assessment. Using visual system may be limited by cloudy and inexperience of tester, then more experience and using colorimeters may be helpful of raising the accurate repeatability of shade selection.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.175-185
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• 2018

Purpose: The aim of this clinical study was to evaluate the efficacy and safety of a self - applied paint - on whitening gel combined with wrap to increase the effect of a whitening gel and minimize gingival irritation. Materials and Methods: Ninety adult volunteers were randomly treated to a control group and two experimental groups using whitening gel containing 2.8% and 3.0% hydrogen peroxide for 30 persons each. They had used the wrap and whitening gel on maxillary 4 anterior teeth for 30 minutes per day during 2 weeks. Whitening tooth color response was measured by VITA shade guide and ShadeEye $NCC^{(R)}$. And side effects were assessed from interview and intraoral examination. The efficacy and safety evaluations were statistically analyzed. Results: In the evaluation with VITA shade guide, there was significantly the whitening effect in experimental groups compared with the control group. In the evaluation with ShadeEye $NCC^{(R)}$, the 3.0% experimental group showed significantly the whitening effect compared to the control group and the 2.8% experimental group (P < 0.05). There were some complaints of minor side effects, but there did not find abnormal symptoms of the gingival stimulation in all groups. Conclusion: A self - applied paint - on whitening gel combined with wrap can be used as a useful self-whitening material because the whitening effect increases as the concentration of hydrogen peroxide from 2.8% to 3.0% and also no significant side effects are observed.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.3
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• pp.219-225
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• 2007

The ability of a dentist to select and communicate an acceptable shade match to a dental laboratory may be the most important factor in esthetic restorative dentistry. However, shade matching is a very complex situation. In this study, an attempt was made to compare and evaluate the conventional visual assessment and colorimetric analysis in clinical shade matching. 20 patients were selected and their maxillary central incisors shade were measured by Vita classic shade guide, using $Shadepilot^{TM}$ and ShadeEye $NCC^{(R)}$. The results indicate that there is much variation in the shade selection by visual and instrumental methods.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.2
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• pp.131-137
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• 2007

The ability of a dentist to select and communicate an acceptable shade match to a dental laboratory may be the most important factor in esthetic restorative dentistry. However, shade matching is a very complex situation. In this study, an attempt was made to compare and evaluate the conventional visual assessment and colorimetric analysis in clinical shade matching. 20 patients were selected and their maxillary central incisors shade were measured by Vita classic shade guide, using $Shadepilot^{TM}$ and ShadeEye $NCC^{(R)}$. The results indicate that there is much variation in the shade selection by visual and instrumental methods.

• Journal of Technologic Dentistry
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• v.33 no.3
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• pp.203-210
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• 2011

Purpose: The purpose of this study was to compare color correspondence of different sizes of Vita Mark II$^{(R)}$ and TriLuxe$^{(R)}$ Feldspar blocks. Methods: The three commercially available shades(1M2, 2M2, 3M2) of Mark II & TriLuxe blocks for the CEREC$^{(R)}$ CAD/CAM system were examined. For each of three colors, three different sizes were tested, 5 blocks each. The measurements were made using a spectrophotometer equipped with an integrating sphere using the CIE $L^*$, $a^*$, $b^*$ colorimetric system. Results: The $L^*$, $a^*$, $b^*$ value of Vita Mark II$^{(R)}$ ceramic block showed significantly higher than TriLuxe$^{(R)}$ ceramic block(p<0.05). In comparing the Vita Mark II$^{(R)}$ specimen of the three different shade, color differences between materials(${\Delta}E^*$) showed the lowest value of 2.09, and the highest was 2.24. ${\Delta}E^*$ values of the materials of Vita Mark II$^{(R)}$ were higher than 2. As the size of ceramic block differed, the color correspondence of Vita Mark II$^{(R)}$ showed statistically significant difference but, this result is clinically acceptable. Conclusion: All the different sizes of the different shades of Vita TriLuxe$^{(R)}$ blocks for the CEREC$^{(R)}$ system showed the high degree of color correspondence necessary in industrially prefabricated CAD/CAM blocks. The results of the present study suggested that it would be necessary to establish the reproducible and constant color specification system for an esthetic restoration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4717-4724
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• 2012

This study is to examine the relation between Korean fermented food and discoloration on teeth, which have undergone profession tooth whitening. The color change of natural tooth, which has undergone professional tooth whitening, is objectively measured by dental colorimeter after being immersed in Korean fermented food for certain period. The tooth specimens used in this study are 30 pieces and measured 30 times per one tooth, 900 times totally by dental colorimeter ShadeEye NCC$^{(R)}$ Dental Chroma Meter. As a result of analyzing the collected data by using PASW(statistical package) 18.0, the significant difference is found (p<0.001) in lightness and yellowness before and after of professional tooth whitening. The lightness and yellowness after immersion is changed (p<0.001) according to time. As a result of examining the degree of discoloration based on type of fluids, the similar difference is indicated (p=0.001, p<0.001 1,2 and 3 weeks after getting professional tooth whitening. As a result, Korean traditional fermented food influences on discoloration on bleached tooth depended on the duration of immersion and the type of fluids. However, this study failed to represent internal oral condition accurately therefore the results of this study could be altered by the internal oral condition, frequency of consumption of food, and the management oral hygiene.

• Journal of Technologic Dentistry
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• v.35 no.3
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• pp.185-192
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• 2013

Purpose: The aim of this study was to compare with color reproducibility of the coating method and dipping method using a colour liquid. Methods: Two groups of square-shaped specimens ($10mm{\times}10mm$ in diameter, 1.5mm thickness) were prepared for analysis(n=15/group). The CM(Coating Method) group was fabricated as full zirconia specimens with the coating coloring method and Group DM(Dipping Method) was prepared as specimens of 0.7 mm-thick zirconia plate using the dipping coloring method and veneered with 0.8mm-thick porcelain. Color parameters were measured with ShadeEye $NCC^{(R)}$ spectrophotometer and color differences were calculated using the equation ${\Delta}E^*= \{({\Delta}L^*)^2+({\Delta}a^*)^2+({\Delta}b^*)^2\}^{1/2}$. Non-parametric statistical methods, the Mann-Whitney test, and the Kruskal-Wallis test were used to analyze the data. Type one error rate was set at 0.05. Results: Color difference values larger than 7 were observed between specimens with the coating method and the dipping method, which were detectable difference in a clinical setting. Conclusion: Cautious application of the coating coloring method in a clinical setting and further researches to standardize the coating method are needed.

• Journal of dental hygiene science
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• v.12 no.4
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• pp.348-358
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• 2012

This study aims to prepare the basic data of the teeth color by measuring analyze mode using the color of the maxillary anterior teeth (maxillary central incisor, lateral incisor, canine) of the college students in their twenties as the dental colorimeter. The maxillary anterior teeth of the subjects of study as 467 students (male 89, female 378) were measured from 14 November to 2 December, 2011, so the color of total 1,401 teeth was examined, and oral health and eating habit attributes were researched. The survey results were as follows. 1. The color of maxillary anterior teeth was changed from maxillary central incisor to maxillary canine, brightness ($L^*$) was decreased $76.79{\pm}4.86$ to $69.72{\pm}4.62$, red chroma ($a^*$) was increased $2.02{\pm}2.00$ to $4.10{\pm}2.60$, yellow chroma ($b^*$) was increased $15.51{\pm}3.42$ to $20.10{\pm}3.46$. 2. Brightness ($L^*$) was different according to sex (p< 0.001), major (p<0.001), grade (p<0.001), smoking (p<0.001), oral health education (p<0.01), daily brushing frequency (p<0.001), brushing method (p<0.05), oral hygiene devices (p<0.001), and red chroma ($a^*$) to major (p<0.001), daily brushing frequency (p<0.05), brushing time after meals (p<0.01), oral hygiene devices (p<0.01), and yellow chroma ($b^*$) to brushing time after meals (p<0.01), subjective tooth color (p<0.001). 3. Brightness ($L^*$) of eating habit attributes was different according to coke, candy ($R^2=0.053$, p<0.05). In conclusion, this study demonstrates that the color of maxillary anterior teeth has differences in brightness ($L^*$), red chroma ($a^*$), yellow chroma ($b^*$) from each tooth, also these showed various tendency according to the oral health and eating habit attributes.

• Journal of dental hygiene science
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• v.12 no.2
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• pp.123-129
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• 2012

The aim of study was to compare the color parameters and mean color difference of porcelain specimens by different veneering technique in order to examine the effect of veneering technique on esthetics of yttria-stabilized tetragonal zirconia polycrystalline(Y-TZP) all ceramic restoration. Three groups of square-shaped core ceramic specimens(14mm in diameter and 0.3, 0.5, 0.7 mm) and two groups of veneering ceramic specimen were prepared for analysis. Color parameter($L^*,a^*,b^*$) and color difference of zirconia core squares and core-veneer specimens were measured with ShadeEye $NCC^{(R)}$ spectrophotometer, respectively. Mean color difference(${\Delta}E^*$)were calculated using color difference formula. Two-way analysis of variance(ANOVA) combined with a Tukey multiple-range test were used to analysis the data(${\alpha}=0.05$). ${\Delta}E^*$ values were not significantly affected by core thickness and veneering porcelain(p=0.083). The color differences(${\Delta}E^*$) of core-veneer specimens with 0.5, 0.7 mm-A1,A2,A3.5 shade were mostly below 3.7 which was within the clinically acceptable range, while color differences between 0.3 mm-A1,A2 showed more than 3.7. All-ceramic system has color characteristics that clinicians have to consider when selecting materials. Also, manufacturers of different porcelain systems must make every effort to achieve color reproducibility.