Evaluation of Color-matching Ability of a Structural Colored Resin Composite

2021 ◽  
Author(s):  
M Saegusa ◽  
H Kurokawa ◽  
N Takahashi ◽  
T Takamizawa ◽  
R Ishii ◽  
...  
Keyword(s):  
Resin Composite ◽  
Color Measurement ◽  
White Background ◽  
Color Matching ◽  
Background Color ◽  
Cavity Depth ◽  
B Values ◽  
Black Background ◽  
Artificial Teeth ◽  
Excellent Color

Clinical Relevance Although excellent color-matching ability was confirmed for the structural colored resin composite Omnichroma, care should be taken to ensure that the appropriate chromatic color conditions for restoration are achieved in the oral environment. SUMMARY Purpose: The present study evaluated the color-matching ability of a structural colored resin composite to compare it with resin composites employing pigments. Methods and Materials: A structural colored resin composite (Omnichroma [OMC]), a supranano-filled resin composite (Estelite Σ Quick [ELQ]), and a nano-filled resin composite (Filtek Supreme Ultra [FSU]) were used. Each resin composite was packed into a Teflon mold and pressed down with a clear strip under a glass slide. The specimens were light irradiated through the slide with a light-emitting diode curing unit. The thickness of the specimens (n=6) was measured with a digital caliper before being transferred to distilled water and stored at 37°C for 24 hours. The measurements of the optical characteristics of the specimens on a black-and-white background were performed using a spectrophotometer. D65 (CIE D65) was used as a light source for the spectrophotometer. Measurements were repeated three times for each specimen under each color-measurement condition, and average values for three same-shade specimens were calculated. One-way analysis of variance and Tukey post hoc tests were used (α=0.05). To determine its ability to match the color of artificial teeth, each shade of resin composite was placed in a cavity before performing color measurements. Using a spectrophotometer (CMS-35F S/C) with a flexible sensor, L*, a*, and b* values were obtained. Results: The spectral reflectance curve of OMC showed that it reflected light wavelengths from 430-700 nm regardless of the background color and thickness of the specimens. The percentage of reflectance of ELQ decreased near wavelengths of 550-580 nm. Regarding the influence of background color on CIE L*, a*, b* values, the L* level showed significantly higher values for all tested materials with white backgrounds, and OMC was most affected by the difference in background color. However, a* values of ELQ and FSU were significantly higher with a black background than with a white background, and OMC showed a significantly higher value with a white background than with a black background. The b* values were higher with a white background than with a black background and were significantly higher for all three products, and these tendencies were much greater for ELQ and FSU. Conclusions: The ability of OMC to match the color of artificial teeth showed acceptable color compatibility, regardless of the shade of the artificial teeth and the depth of the cavity. However, ELQ and FSU showed reduced color compatibility, especially for a cavity depth of 3.0 mm. Excellent color matching ability was confirmed for the structural colored resin composite OMC, resulting in reduced color differences and therefore improving the esthetic appearance of the restoration, simplifying shade matching, and compensating for any color mismatch.

Effects of Background Color and Predation Risk on Color Change in Fire Salamander Larvae

2009 ◽  
Vol 55 (4) ◽  
pp. 359-367 ◽  
Author(s):  
Ori Segev
Keyword(s):  
Predation Risk ◽  
Perceived Risk ◽  
Color Change ◽  
White Background ◽  
Color Matching ◽  
Background Color ◽  
Background Matching ◽  
Threat Sensitivity ◽  
Risk Of Predation ◽  
Fire Salamander

The threat-sensitivity hypothesis assumes individuals should demonstrate flexibility in response to perceived predation risk and vary the intensity of anti-predator responses in concert with perceived risk of predation. Substrate color matching is adaptive as it enables organisms to become less conspicuous to both their prey and predators. I hypothesized that newborn fire salamander (Salamandra infraimmaculata) larvae will respond fast through physiological color change to contrasting backgrounds, becoming lighter against a white background and darker against a black background. Additionally, in accordance with the threat-sensitivity hypothesis, I expected a background color x predator interaction—i.e., that predator presence will further enhance the focal larvae color-matching response. To explicitly test these hypotheses I conducted a replicated outdoor mesocosm experiment. I used a two-by-two factorial design: pools of black or white background color crossed with the presence or absence of a larger cannibalistic conspecific. Digital photos of the focal larvae's dorsal view revealed that larval brightness and chroma changed accordingly against the contrasting black and white backgrounds to increase background matching. Although not statistically significant, larvae tended to show a stronger color-change response towards enhanced background matching in the presence of the free predator. Larval survival was strongly reduced in the presence of the larger conspecific, with no apparent effect of background color. This study demonstrates that Salamandra larvae are capable of environmentally induced physiological color change and highlights the need for further investigation into the interplay between threat intensity, mechanisms of risk assessment, and physiological antipredator responses.

Measuring the Infinite Optical Thickness of Dentine Porcelain of the IPS E.max

2011 ◽  
Vol 492 ◽  
pp. 349-353 ◽  
Author(s):  
Long Quan Shao ◽  
Lin Lin Wang ◽  
Qi Liu ◽  
Bin Deng ◽  
Ning Wen
Keyword(s):  
Optical Thickness ◽  
Chromatic Aberration ◽  
White Background ◽  
Background Color ◽  
Determination Coefficient ◽  
Black Background ◽  
Regression Formula ◽  
Color System ◽  
Best Fit

Dentine porcelain disc specimens 13.0 mm in diameter with thicknesses of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0 mm, were made using IPS E.max color systems B, C, and D and their chromatic aberration values (ΔE) under the standard black background and the standard white background were measured using a Minolta CM-5 spectrophotometer. Then, the cubic regression formula of best fit was used to calculate the thicknesses of dentine porcelains of various color numbers at a ΔE of 1.0 and 1.5. The determination coefficient of the regression formula of color system B was 0.990–0.995, that of color system C was 0.989–0.997, and that of D was 0.993–0.998; and R2is close to 1. The results show that the regression formulas of the 11 thickness groups have good fit. The infinite optical thickness values of the IPS E.max dentine porcelains were as follows: for B1–B4, 3.263–2.711 (ΔE = 1.0) and 2.910–2.493 (ΔE = 1.5); for color system C, 2.727–2.611 (ΔE = 1.0) and 2.473–3.365 (ΔE = 1.5); and for color system D: 2.928–3.694 (ΔE = 1.0) and 2.656–2.458 (ΔE = 1.5). When the chromatic aberration tolerance is 1.5, the thickness of dentine porcelain required to reach the infinite optical thickness is less than the numerical value at ΔE = 1.0. As the thickness increases, the influence of the background diminishes and the specimen looks truer to its inherent color. The results prove that thickness of dentine porcelain positively correlates with its masking ability and that its thickness must exceed its infinite optical thickness so that its color will not be influenced by the background color.

scholarly journals Color-Matching and Blending-Effect of Universal Shade Bulk-Fill-Resin-Composite in Resin-Composite-Models and Natural Teeth

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Rasha M. Abdelraouf ◽  
Nour A. Habib
Keyword(s):  
Resin Composite ◽  
Visual Assessment ◽  
Color Difference ◽  
Color Measurement ◽  
Color Matching ◽  
Occlusal Caries ◽  
Close Match ◽  
Visual Scoring ◽  
Composite Models ◽  
Natural Teeth

Objectives. To assess visually color-matching and blending-effect (BE) of a universal shade bulk-fill-resin-composite placed in resin-composite-models with different shades and cavity sizes and in natural teeth (extracted and patients’ teeth).Materials and Methods. Resin-composite-discs (10 mm × 1 mm) were prepared of universal shade composite and resin-composite of shades: A1, A2, A3, A3.5, and A4. Spectrophotometric-color-measurement was performed to calculate color-difference (ΔE) between the universal shade and shaded-resin-composites discs and determine their translucency-parameter (TP). Visual assessment was performed by seven normal-color-vision-observers to determine the color-matching between the universal shade and each shade, under Illuminant D65. Color-matching visual scoring (VS) values were expressed numerically (1–5): 1: mismatch/totally unacceptable, 2: Poor-Match/hardly acceptable, 3: Good-Match/acceptable, 4: Close-Match/small-difference, and 5: Exact-Match/no-color-difference. Occlusal cavities of different sizes were prepared in teeth-like resin-composite-models with shades A1, A2, A3, A3.5, and A4. The cavities were filled by the universal shade composite. The same scale was used to score color-matching between the fillings and composite-models. BE was calculated as difference in mean-visual-scores in models and that of discs. Extracted teeth with two different class I-cavity sizes as well as ten patients’ lower posterior molars with occlusal caries were prepared, filled by universal shade composite, and assessed similarly.Results. In models, the universal shade composite showed close matching in the different cavity sizes and surrounding shades (4≤VS<5) (BE = 0.6–2.9 in small cavities and 0.5–2.8 in large cavities). In extracted teeth, there was good-to-close color-matching (VS = 3.7–4.4 in small cavities, BE = 2.5–3.2) (VS = 3–3.5, BE = 1.8–2.3 in large cavities). In patients’ molars, the universal shade composite showed good-matching (VS = 3–3.3, BE = −0.9–2.1).Conclusions. Color-matching of universal shade resin-composite was satisfactory rather than perfect in patients’ teeth.

Behavioural and neuroendocrine effects of environmental background colour and social interaction in Arctic charr (Salvelinus alpinus)

2002 ◽  
Vol 205 (16) ◽  
pp. 2535-2543 ◽  
Author(s):  
Erik Höglund ◽  
Paul H. M. Balm ◽  
Svante Winberg
Keyword(s):  
Social Interaction ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Skin Pigmentation ◽  
White Background ◽  
Melanocyte Stimulating Hormone ◽  
Black Background ◽  
Social Signal ◽  
Social Subordination ◽  
Colour Skin

SUMMARYIn salmonid fish, a darker skin colour has been suggested to signal social subordination. Substratum colour is another factor affecting skin pigmentation in fish; in the present experiment, juvenile Arctic charr (Salvelinus alpinus) were acclimated and allowed to interact in pairs for 5 days on a pale or dark background colour. Skin darkness was quantified prior to and following social interaction. Furthermore, agonistic behaviour and skin darkness were quantified, together with plasma levels of cortisol,adrenocorticotropin (ACTH) and α-melanocyte-stimulating hormone(α-MSH), and brain levels of monoamines and monoamine metabolites. The results show that fish interacting on a white background were more aggressive than those interacting on a black background. Social subordination resulted in skin darkening in fish kept on a white background, but not in fish kept on a black background. Furthermore, subordinate fish on a white background showed an elevation of brain norepinephric activity, an effect not seen in subordinate fish on a black background. Subordinate fish on both white and black backgrounds showed a similar activation of the brain serotonergic system and the hypothalamic—pituitary—interrenal axis. These results support the suggestion that skin darkening in subordinates acts as a social signal announcing social submission.

scholarly journals The pigmentary effector system VIII—The dual receptive mechanism of the amphibian background response

1936 ◽  
Vol 120 (817) ◽  
pp. 158-173 ◽  
Keyword(s):  
Normal Animal ◽  
The Other ◽  
White Background ◽  
Pars Intermedia ◽  
Pars Tuberalis ◽  
General Hypothesis ◽  
Common Path ◽  
Black Background ◽  
To Come ◽  
Stimulation Of

In a previous contribution (Hogben and Slome, 1931) evidence was brought forward to show that the white background response does not depend on the same mechanism of coordination as the black background response, which is produced by reflex liberation of a hormone (“B” substance) of the pars intermedia in the pituitary gland; and experiments pointing to the existence of another internal secretion (“W” substance), connected directly or indirectly with the activity of the pars tuberalis, were described. The existence of separate receptor components of the retina controlling the two systems was left for subsequent enquiry. Of two possible hypotheses concerning the nature of the receptive mechanism, the most likely one is illustrated diagrammatically in fig. 1. In normal situations, when an animal is illuminated on a black background, light can only fall on the floor of the retina. If it is aquatic, the maximum divergence of any two rays which strike the eye is twice the critical angle for air and water, so that in the absence of reflexion of rays from sur­rounding objects below the surface of separation all rays will presumably be brought to a sharp focus in shallow water. There are thus three distinct possibilities which arise from the way in which the animal is illuminated if, as in Xenopus , the eyes are situated on the top of the head: ( a ) in darkness no part of the retina is stimulated, the same being true of the eyeless animal; ( b ) when the animal is exposed to a black background only a sharply localized region of the retina is stimulated; ( c ) when the animal is exposed to a white background the whole of the retina is illuminated owing to the scattering of rays in all directions from the surroundings. For convenience of description the usual black back­ground situation will be described hereafter as one in which only the “floor” of the retina is stimulated, and the white background situation as one in which the floor and the “ periphery ” of the retina are both stimulated together. If then, the receptor elements of the floor and periphery initiate different systems of reflex arcs the phenomena of the background response in Amphibia and Reptiles may be interpreted as follows. In Reptiles we may suppose that stimulation of floor reflexly excites the melanophores to expand, while stimulation of peripheral photoreceptors excites them to contract, being presumably prepotent in the final common path. In Amphibia two alternatives may be con­sidered: ( a ) that floor elements reflexly excite liberation of “B” and that peripheral photoreceptors, being prepotent, reflexly inhibit libera­tion of “B"; ( b ) that floor elements reflexly excite liberation of “B”, and peripheral photoreceptors reflexly excite production of the antago­nistic substance “W” in quantity sufficient to over-ride the effect of “B”. The crucial test of the truth of the general hypothesis that the floor and peripheral elements of the retina initiate different processes of coordina­tion was suggested by Keeble and Gamble (1904-6) in their experiments on Crustacea. If it is true, a normal animal illuminated from below in a black tank with a white top should react in exactly the same way as a normal animal when illuminated in a black tank from above. On the other hand, a normal animal illuminated from below in a black tank with a black top should react like an eyeless animal in the same situation, because the floor elements would not be subject to stimulation. The experiment may be varied as indicated below. In order to obtain signi­ficant results two classes of precautions must be carefully observed. One is that the physical dimensions of the tank must not exceed certain limits, since the maximal divergence of two rays is rigidly fixed when an animal is illuminated from above. The other is that there must be no air-water interface to permit reflexion of the incident rays downwards. Aside from the fact that no bubbles must be allowed to collect, this condition presents a practical difficulty if the animal has to come to the surface to breathe.

scholarly journals Comparison between Color Spaces of Vita Lumin Shade Guide with Natural Teeth in Bengaluru Population using Spectrocolorimeter: An in vivo Study

2017 ◽  
Vol 18 (8) ◽  
pp. 683-687
Author(s):  
Deepak Mehta ◽  
Nishant Gupta ◽  
Rohit M Shetty ◽  
Adarsh N Bhat ◽  
Gopalakrishna Srivatsa ◽  
...  
Keyword(s):  
Local Population ◽  
Color Space ◽  
Color Measurement ◽  
Color Spaces ◽  
B Values ◽  
Natural Teeth ◽  
Shade Matching ◽  
Shade Guide ◽  
Shade Selection

ABSTRACT Aim The aim of this study is to compare the color space of Vita Lumin shade guide (SG) with the natural teeth of the local population. Materials and methods A total of 100 maxillary central incisors (100 patients) were subjected to color measurement with a spectrocolorimeter. For each tooth, L*, a*, b* values were recorded. All the shade tabs of Vita Lumin SG were analyzed with a spectrocolorimeter to define the color space covered by the Vita Lumin SG. The L*a*b* values of natural teeth were plotted on separate scattered diagrams and compared. Results About two out of three attributes (luminance and blue spectrum) of the local population of Bengaluru displayed a broader range than those available in Vita Lumin SG. Conclusion The local population requires an SG with an extended range, covering a higher luminance spectrum and broader blue spectrum. Clinical significance Esthetic restorations require accurate shade matching with the adjacent natural teeth, SGs being the mean of shade selection and communication should be comparable to the natural teeth. How to cite this article Shetty RM, Bhat AN, Gupta N, Mehta D, Srivatsa G, Singh I. Comparison between Color Spaces of Vita Lumin Shade Guide with Natural Teeth in Bengaluru Population using Spectrocolorimeter: An in vivo Study. J Contemp Dent Pract 2017;18(8):683-687.

The optimization of color-prediction models for colored cotton fiber yarns

2019 ◽  
Vol 89 (19-20) ◽  
pp. 4007-4014 ◽  
Author(s):  
Liu Yang ◽  
Jing Bai ◽  
Ruiyun Zhang ◽  
Yi Ding ◽  
Feng Ji ◽  
...  
Keyword(s):  
Prediction Models ◽  
Color Difference ◽  
Color Measurement ◽  
Target Color ◽  
Color Matching ◽  
Average Color ◽  
Color Differences ◽  
Computer Aided ◽  
Colored Cotton ◽  
Color Prediction

Color matching is necessary in the manufacture of colored fiber yarns, and its accuracy is one of the main goals in computer-aided color matching. A limited number of pre-colored fibers are blended to match the target color through predicted recipes. Of the color-prediction models applied in computer-aided color matching, two common ones, Stearns-Noechel and Friele, were selected to be modified to improve the color-prediction accuracy in this paper. The models were modified in three ways, in which the pending parameters in the models were determined through statistical analysis depending on median, wavelength, and components; thus, the Stearns-Noechel model was modified to Stearns-Noechel 1, Stearns-Noechel 2, and Stearns-Noechel 3, and the Friele model was modified to Friele 1, Friele 2, and Friele 3. The six modified models were affirmed through 261 colored fiber yarns prepared from five primary cotton fibers, including two-, three-, four-, and five-primary blends. The prediction results of 261 samples showed that Stearns-Noechel 3 had the highest accuracy among the modified Stearns-Noechel models, especially for four-primary blends with an average color difference of 0.50 Color Measurement Committee (CMC) (2:1) units, whereas Friele 1 had the highest accuracy among the modified Friele models, especially for five-primary blends with an average color difference of 0.46 CMC (2:1) units. These results indicate the modified model Stearns-Noechel 3 can be used in color prediction when there are fewer than five yarn components, and Friele 1 can be used for five components with lower color differences that better meet color-matching requirements in practical production.

The impact of varying warning color on e-cigarette advertisements: Results from an online experiment among young adults

2021 ◽  
Author(s):  
Jessica L King ◽  
Connor Simper ◽  
Jacob Razzouk ◽  
Julie W Merten
Keyword(s):  
Young Adults ◽  
Tobacco Use ◽  
Future Research ◽  
White Background ◽  
Chi Square ◽  
Message Effectiveness ◽  
Black And White ◽  
Black Background ◽  
Downstream Effects ◽  
The Impact

Abstract Introduction Advertisement warnings are often overlooked, which reduces the opportunity for risk communication. Methods We used Prolific to survey 1,131 young adults (18-35) who currently used e-cigarettes or tobacco products. We randomized participants to one of four warning conditions: black text on white background (BW), white on black (WB), black on yellow (BY), and yellow on black (YB). We examined associations between condition and attention, recall, ad appeal, perceived message effectiveness (PME), and intentions to use e-cigarettes using chi-square and ANOVA where appropriate. We conducted logistic regressions by condition for attention and recall controlling for demographics and tobacco use. Results The warning was selected as the most attention-capturing area of the advertisement more often by those exposed to yellow warnings than white (59.9% versus 46.8%), even after controlling for demographics and tobacco use (p&lt;.05). Recall was greater among those exposed to yellow warnings than white (44.2% vs. 37.3%), which held in controlled models. There were no significant differences between yellow and white warnings for ad appeals, PME, or intentions to use. In subanalyses, WB warnings generated higher PME (10.1 vs. 9.5) and lower intentions to use e-cigarettes (3.0 vs. 3.3) than BW (each p&lt;.05). Conclusions Yellow warning color increases attention and recall of the warning, but this increase in attention did not translate to differences in downstream effects. Among currently mandated warning variations, the white text on black background warning appears more effective than the black on white. Future research should examine whether differences translate to behavior change. Implications We tested color variations of the FDA-mandated nicotine text warning on e-cigarette advertisements. Yellow variations (yellow text on black background and black on yellow) better captured attention and increased warning recall compared to the mandated black and white warnings. Among the FDA-mandated black on white and white on black warnings, the white on black variation appears more effective, generating higher perceived message effectiveness and lower intentions to use e-cigarettes. Given the difficulty in implementing pictorial warnings in the US, color might represent an alternative to improve warning effectiveness. Findings may also be applicable to those designing tobacco-related health communications.

Effects of Patterning on Flicker Frequency

1983 ◽  
Vol 27 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Jack D. Grimes
Keyword(s):  
White Background ◽  
Significant Finding ◽  
Computer Terminal ◽  
Line Drawings ◽  
Spatial Image ◽  
Black Background ◽  
Luminance Difference ◽  
The Subject ◽  
The Relationship ◽  
Video Format

Flicker was studied as perceived on a raster-scan CRT-based computer terminal in a typical use environment. The subject of the research was the relationship between the perception of flicker and the kind of spatial image presented. Both traditional images (filled white disks or squares) and images consisting of text and line drawings, similar in content to typical graphic computer terminal displays, were used in the study. This study measured the flicker perception of eight people. The most significant finding from this study was that CFF thresholds for some images presented on CRT displays in a typical use setting, differed significantly from more traditional images used in most CFF studies reported in the literature. For the eight images tested, the two which exhibited significantly higher CFF thresholds were lines or text on a black background (patterns 3 and 4). Therefore, an important factor to be considered in the prediction of the flicker characteristics of a 60 Hertz, noninterlaced CRT display in conditions similar to those of this study is the choice of normal video (black background) or reverse video format. The white background video format is likely to flicker when the display luminance is above 20 ft-L while the black background video format threshold was about 80 ft-L for both patterns 3 and 4. Alternatively, this luminance difference corresponds to about a 10 Hertz shift in CFF. In this study, the choice of video format alone, resulted in a luminance difference of 60 ft-L at CFF, or alternatively, resulted in a 10 Hertz shift in CFF at a particular luminance, for images normally found on actual CRT displays.

scholarly journals Development and Validation of the Minnesota Low Vision Reading Test (MNRead) Acuity Chart for the Asante Twi Language

1970 ◽  
Vol 19 (4) ◽  
pp. 2945-2953
Author(s):  
Samuel Bert Boadi-Kusi ◽  
Michael Agyemang Kwarteng ◽  
Emmanuel Asubonteng
Keyword(s):  
Visual Acuity ◽  
Low Vision ◽  
White Background ◽  
Second Phase ◽  
Strong Correlations ◽  
Cross Sectional ◽  
Black Background ◽  
Near Visual Acuity ◽  
Development And Validation ◽  
The Relationship

Aim: To design and validate a MNREAD Asante Twi version reading chart, to aid in the assessment of near visual acuity of natives Ghanaians.Methods: Cross-sectional and experimental designs were employed in phases I and II respectively of this study. The chart was developed using 20 transited pupils in class four in the Kumasi metropolis in phase I and validated in a clinical setting at the Manhyia District Hospital, Kumasi, using students in phase II.Results: A total of 100 participants (mean age; 22.19 ± 1.61 years) were involved in the second phase of this study. A Pearson product-moment correlation coefficient was computed to assess the relationship between MNREAD Asante Twi charts logMAR scores in both eyes. The MNREAD-Asante Twi acuity charts had very strong correlations (r = 0.94, p < 0.001) for MNREAD set 1A (black on white background) scores and MNREAD set 2A (black on white background) for acuity scores. Correlation between MNREAD set 1B (white on black background) scores and MNREAD set 2B (white on black background) scores was r = 0.95, p < 0.001.Conclusion: MNREAD Asante Twi reading chart will enhance the measurement of near visual function in native Ghanaians.Keywords: Asante Twi, MNREAD, Visual Acuity, Near chart, Ghana.

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