• The Journal of Advanced Prosthodontics
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• 제16권2호
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• pp.115-125
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• 2024

PURPOSE. The purpose of this in vitro study was to investigate the fracture resistance, surface hardness, and color stain of 3D printed, CAD-CAM milled, and conventional interim materials. MATERIALS AND METHODS. A total of 80 specimens were fabricated from auto polymerizing polymethyl methacrylate (PMMA), bis-acryl composite resin, CAD-CAM polymethyl methacrylate resin (milled), and 3D printed composite resin (printed) (n = 20). Forty of them were crown-shaped, on which fracture strength test was performed (n = 10). The others were disc-shaped specimens (10 mm × 2 mm) and divided into two groups for surface hardness and color stainability tests before and after thermal cycling in coffee solution (n = 10). Color parameters were measured with a spectrophotometer before and after each storage period, and color differences (CIEDE2000 [DE00]) were calculated. The distribution of variables was measured with the Kolmogorov Smirnov test, and one-way analysis of variance (ANOVA), Tukey HSD, Kruskal-Wallis, Mann-Whitney U tests were used in the analysis of quantitative independent data. Paired sample t-test was used in the analysis of dependent quantitative data (P < .05). RESULTS. The highest crown fracture resistance values were determined for the 3D printed composite resin (P < .05), and the lowest were observed in the bis-acryl composite resin (P < .05). Before and after thermal cycling, increase in mean hardness values were observed only in 3D printed composite resin (P < .05) and the highest ΔE₀₀ value were observed in PMMA resin for all materials (P < .05). CONCLUSION. 3D printing and CAD-CAM milled interim materials showed better fracture strength. After the coffee thermal cycle, the highest surface hardness value was again found in 3D printing and CAD-CAM milled interim samples and the color change of the bis-acryl resin-based samples and the additive production technique was higher than the PMMA resin and CAD-CAM milled resin samples.

• 대한치과보철학회지
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• 제29권3호
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• pp.87-99
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• 1991

The effect of oven firing on the color stability and surface texture of extrinsic stains used characterization and color modification of metal cermic restoration were studied by comparing different temperatures and techniques. They were autoglaze technique, applied glaze technique, two step low-fusing glaze technique and one step low-fusing glaze technique. Autoglaze technique and applied glaze technique were air-fired to manufacturer's recommended temperature. Two step low-fusing glaze technique is separated staining and overglazing. Thin slurry of stain powder were air-fired to $1500^{\circ}F$, Overglaze powder powder was then mixed with seam medium and air-fired to $170^{\circ}F$. One step low-fusing glaze technique is combined staining and overglazing. Thin slurry of stain and glaze powder were air-fired to $170^{\circ}F$. The obtained results were as fellows. 1. Slightly significant color differences by colorimeter were found between different stain application and fusion techniques(P<0.05). 2. Two step low-fusing glaze method showed the most rough surface, especially ceramco orage stain(P<0.05). 3. Surface roughness increased gradually in order of autoglaze, applied glaze, one step low-fusing glaze but they were not significantly different(P<0.05). 4. When two step low-fusing glaze was applied, both color measurement and surface texture were sinificantly different from other groups(P<0.05).

• Restorative Dentistry and Endodontics
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• 제37권2호
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• pp.90-95
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• 2012

Objectives: The purpose of this study was to determine the effect of resin infiltration technique on color and surface hardness of white spot lesion (WSL) with various degrees of demineralization. Materials and Methods: Ten human upper premolars were cut and divided into quarters with a $3{\times}4mm$ window on the enamel surface. Each specimens were separated into four groups (n = 10) and immersed in demineralization solution to create WSL: control, no treatment (baseline); 12 h, 12 hr demineralization; 24 h, 24 hr demineralization; 48 h, 48 hr demineralization. Resin infiltration was performed to the specimens using Icon (DMG). $CIEL^*a^*b^*$ color parameters of the enamel-dentin complex were determined using a spectroradiometer at baseline, after caries formation and after resin infiltration. Surface hardness was measured by Vickers Micro Hardness Tester (Shimadzu, HMV-2). The differences in color and hardness among the groups were analyzed with ANOVA followed by Tukey test. Results: Resin infiltration induced color changes and increased the hardness of demineralized enamel. After resin infiltration, there was no difference in color change (${\Delta}E^*$) or microhardness among the groups (p < 0.05). Conclusion: There was no difference in the effect of resin infiltration on color and hardness among groups with different extents of demineralization.

• 펄프종이기술
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• 제43권5호
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• pp.49-54
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• 2011

Curtain coating has been considered as the best coating technology because it is a coating technology that forms contour coating layer with better coverage. To increase the curtain stability surfactants are being used. In this study, the effect of a surfactant on the stability of curtain coating colors was examined by evaluating dynamic surface tension with a bubble surface tensiometer. Di-2-ethylhexyl sodium sulfosuccinate was used as a surfactant since it showed low dynamic surface tension at low surface age. And we evaluated the influence of surfactant on coating color properties including surface tension, viscosity and curtain stability. The surface tension of coating color was decreased when surfactant addition was increased up to 0.5 pph, but it was leveled off at 0.3 pph of surfactant addition. With the increase of surfactant addition rate, viscosity of coating color were increased. Micelles formed by surfactant contributed to the increase of the viscosity. Curtain stability was improved with the addition of surfactant until it reached up to 0.5 pph. Excessive addition of surfactant (> 0.5 pph) didn't improve curtain stability. This was attributed to Marangoni effect(self-healing) and decreasing of curtain thickness.

• 복식
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• 제54권4호
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• pp.41-53
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• 2004

The significant role of colors in fashion design is not enough to emphasize in terms of one of the important design elements and its influences on the behaviors of the people. The purpose of this research is to examine the traditional Chinese colors and its ways of color combinations to appreciate the Chinese culture and its people. The Chinese traditional costume of Ching Dynasty were investigated through historic records, historic nobles, costume accessories and so on. The results of the study were summarized as follows： (1) The Blue was the most favoured color for clothing among men and women during Ching dynasty and various blues in terms of hue, value and intensities were used. (2) The bright Yellow which had been a symbol of Emperor were prohibited being used among people. Though, the late period of Dynasty, the regulation became not to strict and various shades of yellow families were adapted among People. (3) The Red which had been preferred during Ming Dynasty were constantly favoured for the formal wears of auspicious events such as weddings. (4) Dark color groups were loved for the clothing which were used as a ground colors against the flamboyant patterns revealing strong visual effects through value contrast or primary color combinations. (5) The White had a symbol of mourning and there were some intentions to adopt pale color groups such as mint, jade, gray, moon whit,. silver white to make up for white. (6) Contrast color combinations were one of the basic ways of color combination in Chinese traditional costume. Therefore Chinese color combinations has a strong visual effect and easy to draw attention of people by the contrast of the hue, value or intensity of color. (7) Multi-color combinations were another characteristics of Chinese costume in the formal wears which bears many surface designs. The surface decorated with full of motifs, were appreciated by the people expressing their longings and hopes through the auspicious meanings of patterns and striking visual effects of color combinations.

• 한국염색가공학회지
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• 제11권5호
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• pp.22-29
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• 1999

The increase in color depth of polyester fiber dyed with black disperse dyes was investigated with respect to the kinds of resins and alkali treatment. The color depth of the dyed polyester fiber increased continuously according to the concentration of resins coated onto the fabrics. The alkali treatment to polyester fiber before dyeing also enhanced the color depth. It was thought that the polyester fiber was hydrolyzed by alkali resulting micropores on the sample. And the following treatment with a resin, Jet Black T-101, to the polyester fiber increased the color depth much higher. The successive process of alkali treatment, dyeing and Jet Black T-101 treatment could give the best color depth to polyester fiber. Although the alkali treatment reduced the tensile strength of polyester fiber, the color depth of polyester fiber enhanced sufficiently within the range of practically acceptable weight loss and strength. To analyze the micropore on the polyester fiber formed by alkali treatment, nitrogen porosimeter was used. As the weight loss of polyester fiber treated with alkali increased, the BET(Brunauer-Emmett-Teller) surface area, total pore volume, and average pore size of the sample increased.

• 한국식품영양과학회지
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• 제26권5호
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• pp.831-837
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• 1997

Response surface methodology(RSM) was applied in roasting processes of Polygonatum odoratum roots in order to monitor Hunter color parameters and to optimize organoleptic properties of the tea. In roasting processing based on the central composite design with variations in roasting temperature (110~19$0^{\circ}C$) and roasting time(15~75min), coefficients of determinations($R^{2}$) of the models were above 0.9827(p<0.01) in Hunter color parameters and above 0.7748 in organoleptic properties. Hunter color L and $\Delta$E values of the powdered samples decreased with the roasting processes, whereas Hunter color a and b values increased up to around 59 min at 136$^{\circ}C$ and thereafter showed a decreased tendency. Organoleptic qualities on color, taste and aroma of Polygonatum odoratum tea were improved along with roasting processes, thereby estimating the optimum roasting conditions by RSM for the maximized qualities of organoleptic properties as a range from 127$^{\circ}C$ to 135$^{\circ}C$ and from 60min to 66 min. Hunter color a value(redness) was found to generate a similar response surface to that of organoleptic properties, showing the possibility of quality index in roasting processes of Polygonatum odoratum roots.

• 한국식품영양과학회지
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• 제13권1호
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• pp.1-8
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• 1984

식품이 가지고 있는 고유한 색깔은 소비자의 기호성 또는 영양학적 가치의 지표가 될 수 있으며 가공 및 저장처리조건에 따른 식품의 중요한 인자로 작용 할 수 있다. 따라서, 본 실험에서는 식물성 식품재료의 품종, 성숙도, 성장조건(온도, 수분. 제조공정 별)에 따른 Surface color change를 color & color difference meter와 Munsell disc 색도계(色度計)로 X, Y, Z값을 측정하고 공식에 의하여 Y(one of variation in luminous reflectance), x, y(chromaticity)를 구하여 이로부터 작성한 색도좌표상에서 식품의 색상(hue) 및 강도(chroma)를 산출하여 식품의 색도 변화를 검토하였다. 이와 같이 color & color difference meter와 같은 reflectometer를 이용하여 얻은 data를 중심으로 각각의 chromaticity diagram을 작성, 식품의 저장 및 가공처리별 색도변화를 측정하여 이것을 토대로 식품 품질의 특성을 판정할 수 있는 좋은 기초자료를 얻을 수 있었다.

• Advances in Traditional Medicine
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• 제6권2호
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• pp.112-120
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• 2006

The purpose of this study was to analyze whether quantitative evaluation of the color of the tongue substance using $L^*a^*b^*$ color coordinates system could minimize the problems arising from the different illuminating conditions or not. In controlled 4 different illuminating conditions (by natural light, flashlight, f-number, shutter speed),12 healthy subjects were photographed of their tongue substance through a digital camera (C-2100uz, Olympus Co.), both on the top surface and on the bottom surface of the tongue substance by two examiners, twice at 3 day intervals. Clinician evaluation was also performed grading the redness of the tongue substance in the form of 5-points scale by 6 clinicians. As a result, there was no significant difference in color differences between the color of the tongue substance and the reference red card in the 4 different illuminating conditions. Intra-rater reliability was satisfied and even though limitedly, inter-rater reliability was satisfied. Color differences were significantly correlated with the results by the clinicians, although they were applicable limitedly to specific illuminating conditions. Our results indicate that the application of the color differences in tongue diagnosis could not only evaluate the color information quantitatively, but also minimize the problems arising from the different illuminating conditions and that there was the significant difference in the visual evaluation of the red color of the tongue substance, both between the clinicians and between the illuminating conditions.

• 대한치과보철학회지
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• 제46권6호
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• pp.577-585
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• 2008

STATEMENT OF PROBLEM: The discoloration of anterior teeth restoration is one of the material problems demanding retreatment. OBJECTIVES: To evaluate the color stability and affecting factors on esthetic restorative materials when subjected to accelerated aging. MATERIAL AND METHODS: This study was conducted using porcelain disks (IPS Empress 2-glazed, IPS Empress 2-polished), direct restorative resin disks (SYNERGY Duo) and indirect restorative resin disks (Sinfony, TESCERA ATL). Accelerated aging was done by precipitating the specimens in 38.C distilled water and irradiating with xenon light, and the total irradiation was 397.98 KJ/mm. Color and microhardness change of the specimens were measured before accelerated aging and after 100 hours, 200 hours and 300 hours of accelerated aging, and Surface of the specimens were examined with SEM before and after 300 hours of accelerated aging. RESULTS: 1. After 300 hours' accelerated aging, a ${\Delta}E$ value was 3.3 or lower in IPS Empress 2-glazed, IPS Empress 2-polished and Sinfony. 2. After 300 hours' accelerated aging, gloss was lost and surface changes including microcracks were observed in TESCERA ATL and SYNERGY Duo, and color changes of them ranged between 3.58 and 6.40 ${\Delta}E$ units. 3. During 300 hours' accelerated aging, the microhardness of surface was increased by 3.21 - 19.64% in all kinds of composites resin. CONCLUSION: After 300 hours' accelerated aging, SEM images IPS Empress 2-glazed, IPS Empress 2-polished and Sinfony showed little morphological change and their color changes were considered to be clinically acceptable. And there was significant correlation between microhardness changes and color changes of composites (P < .05).