Background Shading Research Articles

Influence of background color and target tooth shade on shade-matching accuracy

Aim: This study analysed the effect of background color and target tooth shade on visual shade-matching. Materials and Method: Twenty prosthodontists performed visual shade-matching on four different backgrounds (green, grey, white, black) using the Vita Classical shade guide. Two identical shade guides were used for shade-matching. One of them was blinded so that the color codes on it could not be identified. Each observer matched all 16 shade tabs using the second shade guide on four different backgrounds. The effects of background and target tooth shade factors on shade-matching accuracy were analyzed with the Chi-square test. A two-proportion z-test with Bonferroni correction was applied to pairwise comparisons. P

Experimental study of cross-correlation algorithm based on background schlieren quantization in natural thermal convection field

Abstract The background shading technology has shown a wide application potential in many fields. This study aims to study the thermal convection field above the flame. In this study, we established a large field shading system, which is used to observe the flow field distribution and the high temperature probe at the corresponding position above the flame flow field, and then the temperature change map of the corresponding position of the flow field is obtained. The experimental results show the advantages of the large field of view shading system based on background shading technology in the temperature distribution image of the flow field, and make up for the vacancy and deficiency of the application in the optical field. This study is also helpful to better reveal the nature of the combustion process. The development of research will provide a new perspective for the further application of background shading technology.

Ultra-Translucent Zirconia Laminate Veneers: The Influence of Restoration Thickness and Stump Tooth-Shade.

This in vitro study aimed to evaluate the final shade of translucent zirconia laminate veneers with varying thicknesses over teeth with different shades. Seventy-five chairside computer-aided design/computer-aided manufacturing (CAD/CAM) shade A1 third-generation zirconia dental veneers, with thicknesses of 0.50 mm, 0.75 mm, and 1.00 mm, were placed on resin composite teeth with shades ranging from A1 to A4. The laminate veneers were divided into groups based on thickness and background shade. All restorations were evaluated with a color imaging spectrophotometer, to map the veneer surface from A1 to D4. Regardless of the thickness or background shade, all dental veneers showed color alteration from the original shade. Veneers with 0.5 mm thickness tended to display the B1 shade, while veneers with 0.75 mm and 1.0 mm thickness primarily exhibited the B2 shade. The thickness of the laminate veneer and background shade significantly modified the original shade of the zirconia veneer. One-way analysis of variance was performed and a Kruskal-Wallis test was used to determine the significance between the three veneer thicknesses groups. The results indicated that the thinner restorations showed higher values with the color imaging spectrophotometer, suggesting that thinner veneers may result in more consistent color matching. This study underscores the importance of carefully considering thickness and background shade when selecting zirconia laminate veneers, to ensure optimal color matching and overall aesthetic outcomes.

Influence of ceramic thickness, background and cement shade on the translucency of zirconia reinforced lithium silicate and lithium disilicate ceramics.

Although, the influence of cement and background shade on the final color and translucency of zirconia reinforced lithium silicate (ZLS) and lithium disilicate (LDS) ceramics has been previously investigated, there is still little data on the translucency of LDS and ZLS ceramics in decreased thickness (0.4 and 0.6 mm). The aim of this study was to investigate ceramic thickness', background and cement shades' effects on the zirconia reinforced lithium silicate (ZLS) and lithium disilicate (LDS) ceramics' translucency. Totally 160 square-shaped A1 shade LDS and ZLS samples produced in 0.4 and 0.6 mm thicknesses were cemented with light and neutral shade resin cement on A2 and A3 shade composite resin backgrounds. The color notations of specimen were measured and translucency parameter (TP) values were calculated. Factorial ANOVA and Tamhane's T2 multiple comparison statistical analyzes were used. Highest TP values (11.82±0.97) were obtained in ZLS specimens that were 0.4 mm in thickness, cemented on A2 background with light shade resin cement. While, the lowest TP values (9.60±0.55) were calculated in LDS samples that had 0.6 mm thickness, cemented on A3 background with neutral shade resin cement. Material type, thickness, and background shade affected TP values of specimens. The cement and background shade used might change the final translucency of ZLS and LDS ceramics that had 0.4 and 0.6 mm thickness. Key words:Ceramics, lithium disilicate, spectrophotometry, zirconia, dental materials.

Microblading Technique for Tattooing of "Hairstrokes" That Simulate Natural Hair: Eyebrow Tattooing and Correction of Medical Conditions.

Microblading is a rapidly expanding technique in cosmetic and medical tattooing, used for eyebrow correction and conditions of hair loss. Tattooing is performed by hand using a special blade; tiny cuts in the outer skin are filled with dark pigment to simulate a natural hair. Indications, the technique, and the microblading procedure step-by-step are considered in what follows. Details on client selection and a range of pitfalls are discussed. The leading application of microblading is cosmetic tattooing of the eyebrows adding pigmented "hairstrokes" to the natural brow area. Tattooed "hairstrokes" fade in color over months and a repeated "touch up" procedure may be required. Pretreatment with laser removal of tattoos of the past may be indicated when a client requests a "touch up" with another brow in another style, shape, or extension. Microblading carries the risk of scarring. The combination with conventional machine-driven needle tattooing for background shading the skin of the brow is also discussed. Microblading is also used as a corrective intervention in a range of dermatological and medical conditions. Having grown exponentially for cosmetic purpose in the first phase of microblading parallel to acquired refinement, the method is now mature and ready to make further progress on medical indication in the coming second phase. The medical community should welcome this opportunity for supplementary correction with restoration of the normal brow anatomy added to other achievements in dermatological and medical therapy.

Translucency and masking ability of translucent zirconia; comparison with conventional zirconia and lithium disilicate.

The purpose of this study is to evaluate translucency and masking ability of translucent zirconia compared to conventional zirconia and lithium disilicate materials. Three types of zirconia blocks with different yttria contents (3Y, 4Y, 5.5Y) and LS blocks (Rosetta SM) were used. Ten specimens for each group were fabricated with 10 mm diameter, with both 0.8 mm and 1.5 mm thicknesses (± 0.02 mm). All groups of zirconia specimens were sintered and polished according to the manufacturer's instructions. To calculate the translucency parameter (TP), CIELAB value was measured with a spectrophotometer on black and white backgrounds. To investigate the color masking abilities, background shades of A2, normal dentin, discolored dentin, and titanium were used. The color difference (ΔE) was calculated with the CIELAB values of A2 shade background as a reference compared with the values in the various backgrounds. One-way ANOVA and Bonferroni tests were conducted (P < .05). The TP values of zirconia specimens increased as the yttria content increased. All materials used in the study were able to adequately mask normal dentin shade (ΔE < 5.5), but were incapable of masking severely discolored dentin (ΔE > 5.5). On the titanium background, all materials of 1.5 mm thickness were able to mask the background shade, but with a thickness of 0.8 mm, only 3Y-TZP and 4Y-PSZ were able to mask titanium background. All zirconia materials and lithium disilicate specimens used in this study were unable to adequately mask the shade of severely discolored dentin. It is recommended to use 3Y-TZP or 4Y-PSZ with a sufficient thickness of 0.8 mm or more to mask titanium.

Cotton canopy reflectance under variable solar zenith angles: Implications of use in evapotranspiration models

AbstractEvapotranspiration (ET) is an important parameter in hydrologic processes and modelling. In agricultural watersheds with competing uses of fresh water including irrigated agriculture, estimating crop evapotranspiration (ETc) accurately is critical for improving irrigation system and basin water management. The use of remote sensing‐based basal crop coefficients is becoming a common method for estimating crop evapotranspiration for multiple crops over large areas. The Normalized Difference Vegetation Index (NDVI) and the Soil Adjusted Vegetation Index (SAVI), based on reflectance in the red and near‐infrared bands, are commonly used for this purpose. In this paper, we examine the effects of row crop orientation and soil background darkening due to shading and soil surface wetness on these two vegetation indices through modelling, coupled with a field experiment where canopy reflectance of a cotton crop at different solar zenith angles, was measured with a portable radiometer. The results show that the NDVI is significantly more affected than the SAVI by background shading and soil surface wetness, especially in north–south oriented rows at higher latitudes and could lead to a potential overestimation of crop evapotranspiration and irrigation water demand if used for basal crop coefficient estimation. Relationships between the analysed vegetation indices and canopy biophysical parameters such as crop height, fraction of cover and leaf area index also were developed for both indices.

Influence of background shade and resin cement on color change of resin matrix ceramics

ENWEndNote BIBJabRef, Mendeley RISPapers, Reference Manager, RefWorks, Zotero AMA Batak B, Öztürk C. Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology. 2021;74(3):160-165. doi:10.5114/jos.2021.108956. APA Batak, B., & Öztürk, C. (2021). Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology, 74(3), 160-165. https://doi.org/10.5114/jos.2021.108956 Chicago Batak, Burcu, and Caner Öztürk. 2021. "Influence of background shade and resin cement on color change of resin matrix ceramics". Journal of Stomatology 74 (3): 160-165. doi:10.5114/jos.2021.108956. Harvard Batak, B., and Öztürk, C. (2021). Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology, 74(3), pp.160-165. https://doi.org/10.5114/jos.2021.108956 MLA Batak, Burcu et al. "Influence of background shade and resin cement on color change of resin matrix ceramics." Journal of Stomatology, vol. 74, no. 3, 2021, pp. 160-165. doi:10.5114/jos.2021.108956. Vancouver Batak B, Öztürk C. Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology. 2021;74(3):160-165. doi:10.5114/jos.2021.108956.

Using the Model for Improvement and Plan-Do-Study-Act to effect SMART change and advance quality.

Using the Model for Improvement and Plan-Do-Study-Act to effect SMART change and advance quality.

Influence of the background color and thickness of zirconia reinforced glass ceramics on the optical properties compared to lithium disilicate glass ceramics

Statement of problem. Optical properties of contemporary all ceramic restorations are influenced by background color and thickness has dearth of information.Purpose. The purpose of this study was to evaluate the influence of the background color and thickness of zirconia reinforced glass ceramics on the optical properties compared to lithium disilicate glass ceramic.Materials and methods. Fifty six ceramics rectangular plates were made from zirconia reinforced glass ceramic and lithium disilicate glass ceramic plates (n=28). The dimensions of the plates were (14 x 12 mm). The plates of each group were divided into two subgroups of two different thicknesses 1.0, 1.5 mm (n=14). Again, specimens were divided into two divisions according to composite background shade into division (A2 and C3). The ceramic plates of each materials and thicknesses were optically connected with drop of distilled water to either two composite background shades. The color change ΔE between ceramic-composite assembly and ceramic plates was measured for all tested group. The data were analyzed with 3-way ANOVA followed by Bonferroni’s post-hoc test (α= 0.05). Results. ANOVA revealed that background color, ceramic type and thickness had a statistically significant effect on mean ΔL (p<0.05). The interaction between the three variables was not statistically significant (p=0.968). Conclusion. Zirconia reinforced lithium silicate ceramics could decrease the effect of color change of dark background more significantly than lithium disilicate glass ceramic.

The light-dark task in zebrafish confuses two distinct factors: Interaction between background shade and illumination level preference

The light-dark preference task has been commonly used in rodents to screen for anxiogenic and anxiolytic drugs. However, recent adaptations of the light-dark preference test for zebrafish have produced inconsistent results. Several studies have reported that zebrafish exhibit a preference for light, while others have found a preference for black. We suggest the inconsistencies may be the result of confusing certain parameters of the test leading to improper interpretation. For example, researchers often use “light” interchangeably with “white” and “dark” with “black” when these are two distinct factors: level of illumination vs. background shade. In the current study, we use specifically designed preference tanks to investigate the influence of background shade (i.e. white vs. black) and level of illumination (i.e. light vs. dark) on preference and anxiety-like behaviour. Furthermore, we pharmacologically validate our results by quantifying the effects of ethanol, a drug with known anxiety-altering properties, on anxiety-like behaviours. Here we report that zebrafish's preference varies depending upon background shade and level of illumination. We also found that ethanol administration altered behavioural responses in an illumination- and background shade-dependent manner. Our findings reinforce the need to correctly differentiate between these factors when interpreting results obtained with this behavioural paradigm. Lastly, our results show that simple modifications to the experimental tank in which anxiety-related responses are measured can significantly alter behaviour of zebrafish, supporting the need for standardized testing procedures and/or for detailed description of experimental procedures and the apparatus.

Effects of veneering porcelain thickness and background shade on the shade match of zirconia-based restorations.

Background. Effects of veneering porcelain thickness and background shade on the shade match of zirconia-based restorations are unclear. The aim of this study was to evaluate the impacts of veneering porcelain thickness and background shade on the shade match of zirconia-based restorations. Methods. Forty A2 shade veneered zirconia disk specimens (10 mm in diameter) were fabricated, with veneering porcelain thicknesses of 1.6, 1.8, 2.0 and 2.2 mm. Three backgrounds were made of A2 shade composite resin (A2), nickel-chromium alloy (NC) and amalgam (AM). The veneered zirconia specimens were placed on the backgrounds. CIELab values were measured with a spectrophotometer. ΔE values were measured to determine color differences between the specimens and the A2 VITA classical shade (target shade). ΔE values were compared with an acceptability threshold (ΔE=3.7). Repeated measures ANOVA, Bonferroni, and 1-sample t-test were used to analyze data (P<0.05). Results. Mean ΔE values ranged between 1.9 and 5.0. The veneering porcelain thickness, the background shade and their interaction affected the ΔE (P<0.0001). The minimum veneering porcelain thickness for the shade match was 2 mm for NC and 1.8 mm for AM. Conclusion. Veneering porcelain thickness and background shade affected the shade match of zirconia-based restorations. With dark-shaded backgrounds, the amount of veneering porcelain thickness needed for the shade match might be beyond acceptable clinical limits. Tooth-shaded backgrounds are esthetically advocated rather than dark-shaded backgrounds in zirconia-based restorations.

A Standardized Tank Design for the Light Dark Task in Zebrafish

The light dark paradigm is a common behavioral test used to screen a variety of pharmacological agents, including anxiogenics and anxiolytics. Although most often used in rodents, the light dark task has recently been adapted for use in zebrafish. However, a number of inconsistent findings have been reported for this species. Some have found zebrafish to prefer black, while others report a preference for light. Careful analysis of light dark preference experiments using zebrafish reveals significant variation in testing tank design and test conditions, including lighting and substrate color. Additionally, in some experiments the designated dark side of the testing tank is completely covered, producing a "cave-like" environment which further confounds results. Lastly, authors commonly use the terms "light vs. dark" interchangeably with "white vs. black", when these are two separate factors that may influence preference: illumination level vs. background shade. To address these limitations, we designed testing tanks that differentiate illumination vs. background shade preference in zebrafish. This design allows for simple standardization of light dark testing apparatus in zebrafish, and facilitates more reliable comparison across studies.

Color shade matching by mobile applications in dental practice: An experimental comparative in-vitro double-blind study

Background and aimNatural tooth shade selection has been a critical step. Over the last decade, computer aided shade matching instruments appeared in market to facilitate shade matching but they presented some disadvantages as increased expenses. Recently, mobile Apps that can analyze color of an image are available. Material and methodsThis study is an experimental comparative in-vitro double-blind study. Two mobile Apps were selected to test their ability to match shades of anonymous VITA Classical shade guide tabs as compared to a second set of tabs of the same type. The sample size was convenience n = 16. One of the two shade guides was tested by the two mobile Apps (test tabs). The second shade guide was used as a reference for matching (control tabs). Color readings of the two Apps were recorded in terms of RGB and average values of two examiners were recorded and compared. All tabs in the control shade guide were surveyed searching for the correct matching and percentages of correct matchings were calculated. Reliability of mobile applications was tested after 7 days under similar conditions. ResultsA significant difference was found between the two applications in all color ranges (P ≤ 0.05) compared using unpaired t-test. The percentages of correctly matched test tabs with their corresponding control tabs, were 30 and 25%. A significant difference (P ≤ 0.05) was found in RGB values of both applications when comparing repeated RGB readings using paired T-test. Recommendations and conclusionMobile applications used differed significantly in reading all color ranges, especially B values. The degree of accuracy was relatively low. A significant difference was reported between multiple readings of the two Apps. Future studies need to focus on producing more specialized dental Apps for shade selection. Keywords shade matching, computer-aided, shade selection, mobile Apps, RGB.

Correction to: Iron sulfide formation on root surfaces controlled by the life cycle of wild rice (Zizania palustris)

In the online and printed version of this article the Acknowledgements section omitted some information. Additionally, Figures 3 and 4 did not contain proper background shading to depict the life stages. The correct Figures and Acknowledgements section are provided.

Re-examining the factors affecting choice in the light–dark preference test in zebrafish

The light–dark preference test has been extensively used to screen anxiolytic drugs and investigate mechanisms of anxiety with rodents. Recently, this task has been adapted to zebrafish, but a number of inconsistent findings have emerged. For example, some found zebrafish to avoid and others to prefer dark. Given the translational relevance of the zebrafish, its utility in high throughput drug screens, and that anxiety still represents a large unmet medical need, there is an urgent need to resolve these inconsistencies. We propose these inconsistencies are due to lack of distinction between two separate factors: background shade and level of illumination. Here, we systematically manipulated background shade (black vs. white) while keeping the illumination level constant (uniformly illuminated). We also manipulated the level of illumination (illuminated vs. not illuminated) while keeping the background constant (either uniformly black or white). We examined the time-course of numerous behavioural responses under these conditions, and found zebrafish to exhibit a significant preference for the black side of the tank within the first 3min of the test when the illumination level was constant. We found this response, along with other anxiety-like behaviours, to diminish over time. In contrast, we found zebrafish did not exhibit a preference for the unilluminated (dark) side of the tank when the background shade was kept constant. Our results demonstrate a dissociation between illumination level and background shade, shown by a preference for black to white, but not for dark to light, confirming the importance of differentiating these two distinct factors.

Masking properties of ceramics for veneer restorations

Statement of problemThe translucency and opacity of ceramics play a significant role in emulating the natural color of teeth, but studies of the masking properties and limitations of dental ceramics when used as monolayer restorations are lacking. PurposeThe purpose of this in vitro study was to determine the translucency of 6 materials used for veneer restorations by assessing their translucency parameters (TPs), contrast ratios (CRs), and potential to mask dark tooth colors. Material and methodsTen square- or disk-shaped specimens (0.5-mm thickness, shade A2) were fabricated from Vitablocks Mark II (VMII; Vita Zahnfabrik), IPS e.max CAD LT (EMXC LT; Ivoclar Vivadent AG), IPS e.max CAD HT (EMXC HT; Ivoclar Vivadent AG), IPS Empress CAD LT (EMP LT; Ivoclar Vivadent AG), IPS e.max Press LT (EMXP LT; Ivoclar Vivadent AG), and CZR (CZR; Kuraray Noritake Dental Inc). Their luminance (Y) values over black and over white tiles were measured, followed by their color (CIELab) over black tiles and white tiles and shaded A2 (control group), A3.5, A4, and B4 acrylic resin blocks. All measurements were performed using a spectrophotometer in 2 different areas on each specimen. Then CRs, TPs, and color differences (over shaded backgrounds) were determined. Data were subjected to 1-way and 2-way ANOVA (α=.05) for analysis. ResultsMean CR values of EMXP LT were significantly higher than those of the other tested materials, whereas VMII and EMXC HT had the lowest values (P<.001). Mean TP values over black and over white backgrounds of VMII and EMXC HT were significantly higher than those of the other tested materials, while EMXP LT and EMXC LT revealed the lowest values (P<.001). Background shade A4 displayed the highest mean effect (expressed in ΔE* values) on the color of the ceramic materials, whereas shade B4 demonstrated the lowest mean background effect (P<.001). ConclusionsSignificant differences in translucency among the tested ceramics were revealed (P<.001). The EMXC LT and EMXP LT groups were the least translucent under the conditions of this study (P<.001). All tested ceramics exhibited poor masking properties against the A4 background. The color differences of most tested ceramics were more acceptable when tested against the B4 background (ΔE*≤3.3).

Robert Morris's Minimal Sculpture, the Rise of the Gallery Network and the Aesthetics of Commodified Art

During 1962 and 1963, the American artist Robert Morris made an object called Location (Fig. 1). This is a wooden panel, featuring two tones of lavender-grey paint – a paler background shade overlayed with text and arrows in a slightly darker hue.1 The word ‘LOCATION’ appears across its centre and the arrows point towards its four edges. Each side bears the word ‘CEILING’, ‘FLOOR’, or ‘WALL’, emphasising its architectural environment. An alterable, numerical meter is also embedded into its surface at each edge, accompanied by the word ‘FEET’. These meters are all adjusted whenever Location is displayed to show the distance between the panel's edges and the limits of the room. ... By literally pointing beyond its borders, Location insistently highlights its connection with its surroundings. Moreover, by prominently displaying this relationship between the work and its environment on and even within the object's surface, Morris blurred the boundaries between inside and outside, suggesting that Location’s artistic content is substantially defined by its immediate spatial context.2 However, this reading is complicated by the fact that the meters are changeable, which suggests a very different mode of spatiality, presenting the work as something designed for transportation. Any relationship it establishes with a particular room will inevitably be temporary, since Location was not produced for permanent display at a single site, but instead always intended for circulation and exchange. Consequently, Location stages a confrontation between two spatial modes, which simultaneously condition the modern artwork. While an art object’s appearance and meaning are inevitably intertwined with the space and place it occupies, modern works have largely been portable commodities, always already displaced from any site and bound to the flows of the capitalist economy.

Speaking Stata: Shading Zones on Time Series and Other Plots

Background shading of time series and other plots is a common need. For example, we often wish to identify particular periods of recession or war or other distinct conditions. The shading should be laid down before the data elements (for example, data points or lines). Several methods of shading can be effective. Tips are included for automating the production of a series of similar graphs.

Cuttlefish see shape from shading, fine-tuning coloration in response to pictorial depth cues and directional illumination.

Humans use shading as a cue to three-dimensional form by combining low-level information about light intensity with high-level knowledge about objects and the environment. Here, we examine how cuttlefish Sepia officinalis respond to light and shadow to shade the white square (WS) feature in their body pattern. Cuttlefish display the WS in the presence of pebble-like objects, and they can shade it to render the appearance of surface curvature to a human observer, which might benefit camouflage. Here we test how they colour the WS on visual backgrounds containing two-dimensional circular stimuli, some of which were shaded to suggest surface curvature, whereas others were uniformly coloured or divided into dark and light semicircles. WS shading, measured by lateral asymmetry, was greatest when the animal rested on a background of shaded circles and three-dimensional hemispheres, and less on plain white circles or black/white semicircles. In addition, shading was enhanced when light fell from the lighter side of the shaded stimulus, as expected for real convex surfaces. Thus, the cuttlefish acts as if it perceives surface curvature from shading, and takes account of the direction of illumination. However, the direction of WS shading is insensitive to the directions of background shading and illumination; instead the cuttlefish tend to turn to face the light source.