• Proceedings of the KACD Conference
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• 2004.05a
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• pp.333-333
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• 2004

복합 레진을 이용한 심미 수복 시 접하게되는 어려움 중의 하나는 한정된 색상과 일정한 광학적 특성을 가진 복합 레진을 이용하여 각각 서로 다른 광학적 특성을 보이는 다양한 치아들의 색조를 재현하는 것이다. Shade matching을 시행하는 첫 과정부터 술자의 시각적 판단에 의존해야하고 판단에 사용하는 shade guide들도 이미 제공되고 있는 한정된 색상만 비색이 가능하기 때문에 shade guide에 존재하지 않은 색은 술자의 경험과 추측에 의해 결정되어 진다. 최근 컴퓨터나 측색기를 치과 영역에 도입하여 치아의 색을 측정하고자하는 시도가 계속되고 있다. 하지만 이러한 기기를 이용한 측색의 결과도 다양한 인자들의 영향을 받게되며, 비록 인간의 눈을 통해 이루어지는 비색보다는 일정한 결과를 나타낸다 하더라도 현재 치과계에서 사용하는 색상 표현 방법으로는 이렇게 기기를 이용해 측정된 결과값을 활용할 수 없게되는 문제점을 지닌다.(중략)

• The Journal of Advanced Prosthodontics
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• v.16 no.1
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• pp.38-47
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• 2024

PURPOSE. This study aims to evaluate the accuracy of different shade selection techniques and determine the matching success of crown restorations fabricated using digital shade selection techniques. MATERIALS AND METHODS. Teeth numbers 11 and 21 were prepared on a typodont model. For the #11 tooth, six different crowns were fabricated with randomly selected colors and set as the target crowns. The following four test groups were established: Group C, where the visual shade selection was performed using the Vita 3D Master Shade Guide and the group served as the control; Group Ph, where the shade selection was performed under the guidance of dental photography; Group S, where the shade selection was performed by measuring the target tooth color using a spectrophotometer; and Group I, where the shade selection was performed by scanning the test specimens and target crowns using an intraoral scanner. Based on the test groups, 24 crowns were fabricated using different shade selection techniques. The ΔE values were calculated according to the CIEDE2000 (2:1:1) formula. The collected data were analyzed by means of a one-way analysis of variance. RESULTS. For the four test groups (Groups C, Ph, S, and I), the following mean ΔE values were obtained: 2.74, 3.62, 2.13, and 3.5, respectively. No significant differences were found among the test groups. CONCLUSION. Although there was no statistically significant difference among the shade selection techniques, Group S had relatively lower ΔE values. Moreover, according to the test results, the spectrophotometer shade selection technique may provide more successful clinical results.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.13 no.2
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• pp.29-35
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• 2004

최근 심미적인 보철 치료에 대한 사람들의 관심이 높아짐에 따라 자연치와 더욱 조화롭게 보철 치료를 하는 것이 요구되고 있다. 이는 구조적인 심미성과 함께 자연스러운 색조 재현을 통하여 이루어지는데, 자연치의 색조는 매우 다양하고 부위별로 달라질 수 있기 때문에 단순히 shade guide상의 비교만으로는 정확한 색조를 얻기가 어렵다. 이러한 색조 선택의 부정확성 때문에 객관적으로 색조를 분석하는 많은 기계적 장치들이 고안되었고, 최근에 ShadeScan system(CYNOVAD, Canada), Vita Easyshade system(Vident, Canada) 등 디지털로 색조를 평가하는 시스템이 각광을 받고 있다. ShadeScan system은 한 번의 클릭으로 치아 이미지를 채득할 수 있고, 바로 컴퓨터를 통해서 이를 분석하여 원하는 shade map, translucency map 등을 얻을 수 있다. 또한 세 방향에서 조사되는 빛은 자체 calibration을 거쳤기 때문에 주변 광원이나 환경의 영향 없이 객관적으로 치아의 이미지를 채득할 수 있다고 한다. 사실 그 동안 이미지 채득이 객관적이라고 주장하는 많은 system이 있었지만 임상의들은 그 신뢰성에대해 의구심을 보였던 것이 사실이다. 이에 본고에서는 ShadeScan system이 반복 촬영 시 같은 색조재현을 할 수 있는지 실험하여 그 객관성에 대해 살펴보았다.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.443-454
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• 2008

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.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.4
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• pp.443-457
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• 2004

Purpose: The purpose of this study was to analyze and estimate whether each company may produce the color of artificial teeth as it stands, in the standard of vita classical shade guide using ShadeScan$^{TM}$ System. Material and methods: we chose the products of 6 companies -EFUCERA, IVOCLAR, ENDURA, TRUBYTE, DURADENT, and DURACROSS- estimated the shade value of each fixed point(cervical, body, and incisal area) of artificial tooth, and verified the equality among the samples from the same company. Results: First, the variation appeared significant at cervical and incisal area. It means that there were significant differences between cervical and incisal area although the most similar artificial teeth to the patients’natural teeth were provided. Second, the results in the body area showed that the variation between artificial and natural teeth was finite(p<0.05) in that area. Conclusion: it shows that the reproduction of colors of artificial teeth might be successful regarding the body is the most important part for a determination of the color of artificial teeth. However, more complements are necessary for the better reproduction of the color of artificial teeth between cervical and incisal area.

• Restorative Dentistry and Endodontics
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• v.48 no.4
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• pp.40.1-40.8
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• 2023

Objectives: The purpose of this study was to evaluate the influence of eye dominance on color perception, and shade matching. Materials and Methods: A total of 104 participants were selected for the study. There were 3 groups: Group I: 3rd and 4th year dental students and interns (n = 40); Group II: postgraduates (n = 34); Group III: senior residents and faculty members (≥ 6 years of clinical experience) (n = 30). All participants were evaluated for congenital color blindness with Ishihara plates, their dominant eye with Mile's test, and their color perception with the Farnsworth-Munsell 100 hue test. The shade guide test was used for shade matching with a second corresponding set of Vitapan classical shade guides. Results: The results of Mile's test revealed that 60.6% were right-eye dominant and 39.4% were left-eye dominant. There was a statistically significant difference among all participants between the dominant eye and the non-dominant eye in shade matching. Conclusions: The dominant eye has a positive effect on shade matching and the ability to match shades becomes better with an increase in clinical experience.

• 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.

• 대한치과보철학회:학술대회논문집
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• 1999.11a
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• pp.65-65
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• 1999

• Journal of Korean society of Dental Hygiene
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• v.13 no.5
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• pp.901-908
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• 2013

Objectives : The purpose of this study was to evaluate the bleaching effect of 3% hydrogen peroxide containing strip with primer in vivo. Methods : 22 female subjects aged from 20 to 39 years old were recruited after informed consent. They were divided into two groups with control and experimental group. Experimental group was bleached with 3% HP strip with primer, and control group received placebo for 14 days. Color changes were measured with Shade Eye-NCC (Shade Eye-NCC, SHOFU Co., Japan), Shade guide (VITA classical shade guide, $VIDENT^{TM}$, CA, USA) and digital camera image. All collected data were analyzed using SPSS 18.0. Results : At baseline, $L^*$ was $71.75{\pm}3.2$ and $b^*$ was $14.90{\pm}3.6$ in control, and $L^*$ was $71.3{\pm}3.4$ and $b^*$ was $15.61{\pm}3.7$ in experimental group. At day 14, $L^*$ was $71.35{\pm}3.2$ and $b^*$ was $13.97{\pm}4.3$ in control, and $L^*$ was $73.51{\pm}2.0$, $b^*$ was $9.10{\pm}3.0$ in experimental group. ${\Delta}E^*$ of all teeth were statistically significant between the two groups. Final ${\Delta}E^*$ was $7.15{\pm}2.09$ at experimental group and $2.78{\pm}2.93$ at control group, and the difference was significant (p<0.005). Color changes using shade guide also significantly decreased at 14th day compared with baseline at experimental group (p<0.005). Conclusions : 3% hydrogen peroxide strip with primer revealed effective enough to bleaching the human enamel during 14 days without any soft and hard tissue irritations.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.269-281
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• 2006

This study evaluated the effectiveness and safety of an experimental bleaching strip (Medison dental whitening strip. Samsung medical Co., Anyang, Korea) containing 2.9% hydrogen peroxide. Twenty-three volunteers used the bleaching strips for one and a half hour daily for 2 weeks. As control group. the same strips in which hydrogen peroxide was not included were used by 24 volunteers with the same protocol. The shade change (${\Delta}E^{*}$, color difference) of twelve anterior teeth was measured using Shade Vision (X-Rite Inc., S.W. Grandville, MI, USA). Chroma Meter (Minolta Co., Ltd. Osaka. Japan) and Vitapan classical shade guide (Vita Zahnfabrik, Germany). The shade change of overall teeth in the experimental group was significantly greater than that in the control group (p < 0.05) and was easily perceivable. The change resulted from the increase of lightness (CIE $L^{*}$ value) and the decrease of redness (CIE $a^{*}$ value) and yellowness (CIE $b^{*}$ value). The shade change of individual tooth was greatest in canine. and smallest in central incisor. The safety of the bleaching strip was also confirmed.