• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.215-226
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• 1993

Color stability of tooth colored restorative resins is an important factor, particularly in anterior teeth restoration. The purpose of this study was to evaluate the color stability and opacity change of several light curing composite resins. Specimens of eight composite resins(Prisma AP. H., Brilliant Enamel, Charisma, Durafil, Helio Progress, Herculite XR, P-50 and Silux Plus) were divided into two groups : In Group 1, the specimens were polymerized by visible light curing unit for 60 seconds on both sides and in Group 2, the post-cured specimens were heat tempered by light/heat curing unit for 45 units(about 18 min.). All specimens were stored in distilled water at $60^{\circ}C$ for 30 days. The color characteristics($L^*,a^*,b^*$) and opacity of the specimens before and after immersion were measured by spectrocolorimetry and the total color difference(${\Delta}E^*$) and opacity change (${\Delta}Y%$) were computed. The results obtained were as follows : 1. SP and APH in both groups, DF, HP and HXR in Group 1 showed ${\Delta}E^*$-value above 2.0. 2. DF, HP, SP and HXR in Group 1 showed higher ${\Delta}E^*$-value than in Group 2, but the others had no significant difference. 3. The opacity of CH and HXR in Group 1, and of CH and BE in Group 2 decreased after immersion, while that of the others increased. 4. Opacity change of BE, P50 and HXR was significantly different between Group 1 and 2. These results suggest that color change in the post-cure heat tempered specimens by light/heat curing unit was smaller than that of the specimens polymerized by visible light curing unit. No clinically detectable opacity changes were noted for any materials in either goup.

• 헤리티지:역사와 과학
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• 제48권3호
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• pp.46-59
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• 2015

본 연구는 문화재에 적용 가능한 다양한 훈증방법 중에서 에틸렌 옥사이드(Ethylene oxide)를 포함하는 훈증 약제가 문화재 재질에 미치는 영향을 평가하였다. 이를 위해 지류, 섬유, 금속, 안료 등 4종류의 시험편을 제작하고 훈증처리 전 후의 색상, 무게, 표면 변화, 그리고 지류와 섬유 시험편에 대한 적외선 분광분석을 실시하였다. 훈증처리는 약제를 처리하지 않은 무처리군을 대조군으로 하고 에틸렌 옥사이드 + $HFC_{134a}$, 에틸렌 옥사이드 + $CO_2$ 등 2종류의 훈증제 처리군을 실험군으로 하였다. 색차 측정 결과, 소다회를 이용하여 증해한 한지, 은, 면, 견, 모시, 황색 안료 등에서 색상 변화가 확인되었으며 특히, 은 시험편에서 평균 6.0 이상의 높은 색차 변화가 측정되었다. 그러나 은 시험편의 경우 훈증제를 처리하지 않은 무처리 시험편의 색차가 약제를 처리한 것보다 오히려 높게 나타나 훈증제 처리가 시험편의 색상 변화에 결정적인 영향을 미치지 않은 것으로 판단되나 훈증처리 시 주의가 요구된다. 무게 측정에서는 전체적으로 0~2% 정도의 변화가 나타났으며, 금속 시험편의 변화가 가장 적었고 지류 시험편의 변화가 가장 큰 것으로 나타났다. 시험편의 표면을 현미경으로 관찰한 결과, 일부 시험편 표면에서 색상 변화가 관찰되었으며, 은 시험편에서 가장 큰 변화가 확인되었다. 그러나 지류와 섬유 시험편을 대상으로 한 적외선 분광분석 결과에서 성분상 변화는 확인되지 않았다.

• 치위생과학회지
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• 제22권1호
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• pp.57-66
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• 2022

Background: This study aimed to investigate the effect of selecting commercially available blending teas and applying them to bovine teeth on color change over time. Methods: After selecting healthy bovine teeth, using a cutting-disc, 105 specimens with a dimension of 5×5×3 mm were prepared, and 15 specimens were distributed to each group. Black tea was used as a positive control, water was used as a negative control, and blended tea of five types was used as an experimental group. First, pH and buffering capacity were measured with a pH meter, and tooth color was determined using a spectrophotometer before immersion in the blending tea solution and 1, 5, 7, 14, and 21 days after immersion. Thereafter, the shape change of the enamel surface was observed using a scanning electron microscope, and SPSS ver.26 was used to analyze the color change. Results: The average pH of the five blending teas in the experimental group was 3.78, and the pH of group 3 (strawberry rhubarb) was the lowest at 3.22. The pH levels of black tea and water were 5.19 and 7.30, respectively. The buffering capacity was the highest in group 3 at both pH levels of 5.5 and 7.0. The L^*a^*b^* color change according to immersion time was the largest in group 4 (rooibos yellow flower), and the amount of color change was large in black tea and group 4. As a result of observing the enamel surface of bovine teeth, changes in the surface shape were noted in all groups immersed in the experimental solution for 21 days, except for water. Conclusion: There was a significant difference between the experimental groups in terms of color change according to the immersion time, and color and enamel surface changes were observed in black tea and all experimental groups, except for water.

• 대한치과기공학회지
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• 제30권1호
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• pp.33-39
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• 2008

Recently natural characteristics and esthetics have been interested increasing in clinical dentistry. Thus the evaluation of the shade of dental porcelain has become an important part in dental research. Noritake Super Porcelain EX-3 Vita shade A2 (Noritake, Japan) Vintage HaLo Vita shade A2 (Shofu, Japan), Vita omega 900 Vitapan 3D-master shade 2M2 (Vita, Germany) were conducted for six times for repeated firing in a way to observe the change of color with respect to the number of firing. The repeated firing was implemented with the vacuum firing and air firing, and by using Shade Eye-EX Chroma meter (Shofu, U.S.A.), the changes in values of shade, value and chroma were compared. With the above results, the change of color was not noticed only in Vita when repeated firing was applied.

• 대한치과기공학회지
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• 제33권3호
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• pp.219-224
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• 2011

Purpose: The current study focused on investigating color change of dental zirconia block with respect to the block coloring time. Methods: Three types of dental zirconia blocks(Zirtooth, Pearl-HT, D-Max) were tinted with coloring agent under four different time condition (0 minutes, 1 minutes, 10 minutes, 30 minutes). The quantitative evaluation of the tinted dental zirconia blocks was conducted with spectrophotometer. Results: The Zirtooth and D-Max blocks showed lower H value. The Pearl-HT blocks showed poor reflectivity(L value). Conclusion: The study of color change of zirconia block, which consists the substructure of all ceramic Crown, is applicable for deciding appropriate coloring condition when fabricating one layer ceramic Crown or double layer ceramic Crown.

• 약학회지
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• 제37권2호
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• pp.198-203
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• 1993

Physico-chemical properties of methyl 5-hydroxy-dinaphtho[1,2-2',3'] furan-7,12-dione-6-carboxylate(MHDDC) were examined. The yellowish color of the solution at pH 8 below changes to a bluish color when the solution is basified to pH 10 above. This color change was presumed to a change of the molecular structure from a quinoid-type to a quinoid-type with the dissociation to the hydroxyl group as shown in chart 1.

• 한국콘텐츠학회논문지
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• 제10권12호
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• pp.236-242
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• 2010

심미보철의 금속-도재관은 금속소재의 하부구조에 도재를 단계별로 소성하여 제작된다. 최근 새로운 기술인 SLM법을 이용하여 하부구조를 제작하고 있다. 본 연구에서는 금속-도재관의 하부구조를 주조법과 SLM법으로 제작하고 도재를 단계별로 소성하여 도재소성단계와 제작방법에 따른 색조변화를 측색기를 이용하여 관찰하였다. 도재의 소성단계에 따른 색조변화는 불투명도재 소성한 시편군(CN1, CC1, CT1, SC1, ST1)이 몸체도재소성 시편군(CN2, CC2, CT2, SC2, ST2)과 광택소성 시편군(CN3, CC3, CT3, SC3, ST3)과 색차(${\Delta}E$=30이상)를 나타냈다(p<0.05). 그리고 제작방법에 따른 색조관찰은 주조법으로 제작된 하부구조(CN, CC, CT)와 SLM법을 제작된 하부구조(SC, ST)간의 색차(${\Delta}E$=1.5이하)는 없는 것으로 나타났다. 따라서 도재의 소성단계에서는 몸체도재소성에서 색조가 표현되며, SLM법으로 제작된 금속-도재관의 색조는 임상적용이 가능한 것으로 판단된다.

• 패션비즈니스
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• 제21권3호
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• pp.14-28
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• 2017

This purpose of this study to analyze effect material properties have on change in QR code recognition rate according to change of materials by comparing recognition rate of color QR code. QR code applied to textile materials has the advantage of being washable and being applicable to lost child prevention goods or clothes or a person with dementia through record of information relating to the material or input of additional information, differently from QR code printed on the conventional paper. An effective method of entering QR code in textile materials is Digital Textile Printing(DTP), that facilitates printing by rapidly applying diverse information, and small quantity production. It is possible to tailor various QR codes according to use. Regarding samples to use, cotton material used in clothing products and Tyvek material recently applied to clothing and related products were selected. Reactive dyes were used for cotton, pigment was used for Tyvek, and QR code was printed with an inkjet printer by direct printing method. Printing methods and surface textures are different between cotton and Tyvek. It was revealed that consequent print results and results of recognition rate were different. Regarding color to be printed, 2015 S/S - 2017 S/S color presented by Pantone was used. Color combination affected recognition rate of color QR code. Understanding color combination, material properties and print characteristics may be helpful in increasing recognition rate of color QR code, and may contribute to usability of color QR code applied to textile materials in the future.

• 복식문화연구
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• 제6권1호
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• pp.58-70
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• 1998

The color difference value of fabrics dyed with browning extracts from mushroom were as follows. 1. Two hours of dyeing depending on pH at 95℃ exhibited colors of YR and Y. The color of wool and nylon was darkest brown at pH 4, but light brown or yellow as pH increased. The color of silk was darkest brown at pH 5 and pH changes resulted in the same tendency as in wool. 2. In wool the color was changed to darker brown as time prolonged, however, there was no further color change after 9hr and value and chroma of wool declined. 3. At pH 4, the increase in temperature turned colors of sil, wool and nylon into dark brown from light yellow. 4. As the result of repetitive dyeing, colors of silk, wool and nylon gradually turned into darker brown. The repetitive dyeing was more effective in dark color and high colorfastness compared to a prolonged dyeing. 5. The amount of mordant resulted in color changes between light yellow and dark brown without various color changed. 6. In color change according to methods of mordant, post-mordant with CuSO₄·5H₂O and with SnCl·2H₂O showed colors of green and light yellow, respectively.

• 대한가정학회지
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• 제41권9호
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• pp.43-54
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• 2003

The purpose of study is to survey the system of the Korean Gangsin-mu shaman costume and its formative character and to fine out the traditional follow patterns of government officials' attires and Po's meaning of it. The overall shape of variety 'Po's in modern times are similar to the traditional ones, but they differ greatly in size, detail color, and ornamental design. The sleeves have slits in the armholes, which can allow the hands to be drawn out easily. In addition, the knot buttons are used in the modern costumes. They are based on different formation skills from those of the traditional The original color of the shaman's costume is not their taste in color but symbolic, modern costumes color show the shaman's taste in color. This change mean a more accentuated visual effect than incantatory meaning. Another reason for color change is also the costume's material. A kind of constituent element uses synthetic fiber in modern times.