scholarly journals Color changes of esthetic elastomeric ligatures evaluated with the Commission Internationale d'Éclairage color system

2018 ◽  
Vol 12 (03) ◽  
pp. 428-433
Author(s):  
Vanessa Dias da Silva ◽  
Caroline Dias ◽  
Leandro Berni Osório ◽  
Paulo Ricardo Baccarin Matje ◽  
Luciane Macedo de Menezes ◽  
...  
Keyword(s):  
Statistical Difference ◽  
Color Change ◽  
Multiple Comparisons ◽  
Color Changes ◽  
Color Differences ◽  
Color System ◽  
Total Color Change ◽  
Cie Color System ◽  
Spearman’S Correlation

ABSTRACT Objective: The aim of this study was to assess and compare color changes in esthetic elastomeric ligatures after 30 days in situ using a spectrophotometer and the Commission Internationale d'Éclairage (CIE) color system. Materials and Methods: The sample comprised elastomeric ligatures of four color groups (n = 42): blue pearl (BP); colorless; white pearl (WP); and pearl. Four samples from each group were allocated in for quadrants of seven patients in a split-mouth model. Color measurements were performed with a spectrophotometer in the elastomeric ligatures as received (T0) and after 30 days in situ (T1). Variables L*, a*, and b* were compared between times (T1–T0) with Wilcoxon paired ranks; color changes were compared between groups with Kruskal–Wallis test; Dunn's test was used for multiple comparisons. Spearman's correlation was applied between CIELAB and CIEDE2000 calculations. Results: All groups showed color changes (T1–T0) in a* and b*, but only the Group BP had a change in L* (P < 0.01). Group C showed the greatest lightness decrease (ΔL = −2.49 ± 0.47) (P < 0.05), the smallest yellowing (Δb = 3.17 ± 0.88) (P < 0.05), and the smallest total color change (ΔE2000 = 3.19 ± 0.85), which had no statistical difference from Group WP (ΔE2000 = 3.36 ± 0.53). Correlation between ΔEab and ΔE2000 was moderate (r = 0.59; P < 0.01). Conclusions: Esthetic elastomeric ligatures became yellowish after 30 days in situ, and there were color differences between them.

scholarly journals Changes of quality of rennets during storing

2012 ◽  
Vol 60 (6) ◽  
pp. 189-196
Author(s):  
Monika Kozelková ◽  
Miroslav Jůzl ◽  
Táňa Lužová ◽  
Květoslava Šustová ◽  
Aneta Bubeníčková
Keyword(s):  
Near Infrared ◽  
Color Change ◽  
Coagulation Time ◽  
Time Activity ◽  
Spectrophotometric Methods ◽  
Color Changes ◽  
Rennet Coagulation ◽  
Total Color Change ◽  
Instrumental Methods

This work deals about evaluation of qualitative parameters of rennets. During the six months storing of rennets were determined following qualitative parameters: pH, rennet coagulation time, activity (strange) of rennet and dose of rennet, and finally were used instrumental methods: Near infrared spectroscopy (NIR) for recognizing age of rennets and spectrophotometric methods of determining the color of rennets. The theory found in the references suggests, that the activity of rennet should decrease by an average of 1–2 % per month, but the results are showing, that are changing quality of rennets namely mostly activity (strange) of rennet, which was decreased by 33% per half year. In analysis of color of rennets weren’t observed major changes by the whole group. Some statistical differences were detected in the partial values L*a*b*, most advantageous were evaluation by rennet total color change during storage, which were higher than noticeable change in four samples. The least color changes (P > 0.05) were observed in microbial rennets, with no values observed (ΔEab < 2) that can be recognized even by the human eye when subjected to parallel comparison. It was found that the NIR analysis can be used to recognizing of rennets, which are different ages.

scholarly journals Assessment of changes in color and color parameters of light-cured composite resin after alternative polymerization methods

2013 ◽  
Vol 07 (01) ◽  
pp. 110-116 ◽  
Author(s):  
Emine Sirin Karaarslan ◽  
Bulbul Mehmet ◽  
Ertas Ertan ◽  
Mehmet Ata Cebe ◽  
Aslihan Usumez
Keyword(s):  
Composite Resin ◽  
Color Change ◽  
Color Difference ◽  
Study Groups ◽  
Color Parameters ◽  
Color Changes ◽  
Yellow Color ◽  
Before And After ◽  
Total Color Change

ABSTRACTObjective:To examine the amount of change in color and color parameters of a composite resin (Filtek P60) polymerized by five different polymerization methods.Methods: A Teflon mold (6mm in diameter, 2mm in height) was used to prepare the composite resin discs (n=10). G1: Polymerization with inlay oven; G2: Polymerization with HQTH and autoclave; G3: Polymerization with LED and autoclave; G4: Polymerization with HQTH; G5: Polymerization with LED. Colorimetric values of the specimens before and after polymerization were measured using a spectrophotometer. The CIE L*a*b color system was used for the determination of color difference. Analysis of variance (ANOVA) was used to analyze the data for significant differences. Tukey’s HSD test and paired two-tailed tests were used to perform multiple comparisons (α=.05).Results: There were no significant differences in total color change (ΔE*ab) among the polymerization groups (P>.05). However, the lowest color change (ΔE*ab) value was 3.3 in LED and autoclave; the highest color change (ΔE*ab) value was 4.6 in HQTH. For all groups, CIE L*, C*ab and a*values decreased after polymerization (P<.05). The highest Δb* and ΔC*ab values were observed in specimens polymerized in an inlay oven (P<.05).Conclusion: Composite resin material showed color changes above the clinically accepted value in all study groups (ΔE*ab≥3.3). All specimens became darker during investigation (ΔL*< 0). Specimens polymerized with inlay oven presented the highest Δb* values which means less yellow color in specimens. (Eur J Dent 2013;7:110-116)

scholarly journals Color stability of esthetic coatings applied to nickel-titanium archwires

2017 ◽  
Vol 46 (5) ◽  
pp. 307-311
Author(s):  
Marcus Vinicius Neiva Nunes do REGO ◽  
Geórgia Wain Thi LAU ◽  
Yago Carneiro ARAÚJO ◽  
Rayssa Melo e SILVA
Keyword(s):  
Epoxy Resin ◽  
Color Change ◽  
Color Stability ◽  
Surface Characteristics ◽  
Nickel Titanium ◽  
Staining Solution ◽  
Color Changes ◽  
Significant Difference ◽  
Total Color Change ◽  
Coating Type

Abstract Introduction Color stability is an important feature to be considered when using esthetic coated archwires. Objective To evaluate color changes on the surface of esthetic nickel-titanium archwires coated with Teflon (Ortho Organizers, USA) or epoxy resin (Tecnident, Brazil) after immersion in staining solution. Material and method Twelve 20-mm-long wire segments were used for each type of coating, which were mounted as two test specimens with a width of 7 mm each. The buccal surface of the archwires was evaluated for fluorescence and color measurements both at baseline and after immersion in a staining solution for 21 days using the VITA Easyshade® Compact spectrophotometer (Model DEASYC220). Differences in total color change according to coating type were compared using an independent samples t-test (p<0.05). The surface characteristics of as-received coated archwires were assessed using scanning electron microscopy. Result Color changes were observed on the esthetic coatings, with a significant difference between the two brands analyzed. Surface analysis revealed flaws such as wear, pitting, elevations, lack of material, granulation, grooves, cracks, and lack of standardization in the coating process in all as-received archwires, but flaws were less evident in epoxy-resin coatings. Conclusion The two esthetic coatings did not show color stability, but Teflon coatings showed a more intense color change than epoxy-resin coatings.

Assessment of spoilage potential posed by Alicyclobacillus spp. in plant-based dairy beverages mixed with fruit juices during storage

2020 ◽  
Author(s):  
ANASTASIA KAPETANAKOU ◽  
Konstantina Passiou ◽  
Kalliopi Chalkou ◽  
Panos Skandamis
Keyword(s):  
Color Change ◽  
Inoculum Size ◽  
Fruit Juices ◽  
Mitigation Strategies ◽  
Initial Inoculum ◽  
Color Changes ◽  
Beverage Industry ◽  
Total Color Change ◽  
And Storage ◽  
Dairy Beverages

The scope of the present study was to assess the spoilage potential of different Alicyclobacillus spp. in commercial pasteurized (ambient-stable) plant-based dairy beverages mixed with fruit juices at different inoculation levels and storage temperatures. Different products (Coconut and Berry‒CB; Almond, Mango, and Passionfruit‒AMP; Oat, Strawberry, and Banana‒OSB) were inoculated with 10 or 2x103 spores/mL of either Alicyclobacillus acidoterrestris or A. fastidiosus or A. acidocaldarius strain composites, while non‒inoculated samples served as controls. Samples inoculated with A. acidoterrestris and A. fastidiosus were stored at 30°C and 45°C, while in case of A. acidocaldarius storage took place at 50°C for 240 days. Gas composition, Alicyclobacillus spp. populations, total viable counts, pH, aw, color, and guaiacol off-taste were monitored. CB and AMP supported growth of A. acidoterrestris and A. fastidiosus, reaching populations of 4.0‒5.0 log CFU/mL. In OSB, populations of the latter species remained close to the initial inoculation levels during storage at 30°C, while at 45°C, the populations declined &lt;1 CFU/mL. A. acidocaldarius growth was supported only in CB samples, reaching ca. 3.0 log CFU/mL at 50°C, regardless of initial inoculum size. Total color change was increased during storage, however the instrumentally recorded color changes were not macroscopically visible. Spoilage in terms of guaiacol off-taste, was identified only in CB and AMP samples inoculated with A. acidoterrestris after 60 days at 30°C and 45°C. Considering that these products are becoming increasingly popular and the scarcity of existing literature related to their spoilage by Alicyclobacillus spp., the contribution of the findings and data of present study are critical for assessing the significance of Alicyclobacillus spp. as a potential spoilage hazard in these products and thus, to assist in the design and implementation of effective mitigation strategies by the beverage industry.

scholarly journals The Effects of Natural Weathering on Color Stability of Impregnated and Varnished Wood Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Turkay Turkoglu ◽  
Ergun Baysal ◽  
Hilmi Toker
Keyword(s):  
Scots Pine ◽  
Color Change ◽  
Color Stability ◽  
The Other ◽  
Natural Weathering ◽  
Color Changes ◽  
Oriental Beech ◽  
Total Color Change ◽  
Dark Color ◽  
Copper Arsenate

The aim of this study was to investigate effects of natural weathering on color stability of Scots pine (Pinus sylvestrisL.) and Oriental beech (Fagus orientalisL.) impregnated with some chemicals [tanalith-E (TN-E), adolit-KD5 (AD-KD5), and chromated copper arsenate (CCA)] and then varnished [synthetic varnish (SV) and polyurethane varnish (PV)]. While applying varnish increased lightness, impregnation decreased lightness of the wood specimens before natural weathering. Natural weathering caused greenish, bluish, and dark color tones of the wood surface. Total color change was increased with increasing exposure times in natural weathering. Untreated (control) wood specimens exhibited higher color changes than the other wood specimens in all the stages of natural weathering. The total color changes of untreated Oriental beech specimens were less than untreated Scots pine specimens. The color stability of impregnated and varnished wood specimens gave better results than untreated and solely varnished wood specimens after natural weathering. The best color stability was obtained from both Oriental beech and Scots pine wood impregnated with TN-E before PV coating.

Color Changes upon Cooling of Lepidoptera Scales Containing Photonic Nanoarchitectures

2013 ◽  
Vol 543 ◽  
pp. 18-21 ◽  
Author(s):  
István Tamáska ◽  
Krisztián Kertész ◽  
Zófia Vértesy ◽  
Zsolt Bálint ◽  
András Kun ◽  
...  
Keyword(s):  
Color Change ◽  
Ambient Air ◽  
Controlled Cooling ◽  
Simple Method ◽  
Color Changes ◽  
Reflectivity Spectra ◽  
Display Technology ◽  
Crystal Type ◽  
Intense Color

Photonic crystal type nanoarchitectures have an important advantage over conventional displays: they do not fade under solar illumination; on the contrary, more intense illumination generates more intense color. We present a simple method based on cooling in ambient air - to observe the color change of several butterfly wings colored by various photonic nanoarchitectures. The color change can be attributed to the condensation of atmospheric humidity in the nanocavities of the photonic nanoarchitecture. The effects were investigated by controlled cooling combined with the in-situ measurement of the changes in the reflectivity spectra. For certain species the reflectivity maximum (color) has almost completely disappeared. A correlation was also found between the openness of the nanostructure and the time of the color change. Cooling experiments, using thin copper wires showed that color alteration could be limited to millimeters; this may offer a possible alternative for display technology.

Effect of Heat Treatment Temperature on the Color of Okan Wood

2011 ◽  
Vol 214 ◽  
pp. 531-534 ◽  
Author(s):  
Qiang Shi ◽  
Fu Cheng Bao ◽  
Jian Xiong Lu ◽  
Jing Hui Jiang
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Color Change ◽  
Treated Wood ◽  
Color Difference ◽  
Treatment Temperature ◽  
Strong Correlations ◽  
Color Changes ◽  
Color System ◽  
Effect Of Treatment

In this study the effect of high temperature on color change of okan wood was investigated. Wood specimens were subjected to heat treatment at 160°C, 180°C,200°C,220°Cfor 4 hours with the superheated steam as a heating medium and a shielding gas. Color changes were measured in the Minolta Croma-Meter CR-300 color system. The color parameters L*, a*, b* were determined by the CIEL*a*b* method on the surface of untreated and treated wood, and their variation with regard to the treatment (△L*,△a*,△b* ) were calculated. It was found that heat treatment resulted in a darkening of wood tissues, Color became dark with the temperature increases. The darkening accelerated when treatment temperature exceeded approximately 200°C. We found that heat treatment temperature were substantially important regarding the color responses. Strong correlations between total color difference and the treatment temperature were found. The effect of treatment temperature on color change in sapwood is more obvious than that in heartwood, the color of sapwood and heartwood tended to be more uniform when the temperature reaches more than 200°C.

scholarly journals The Effect of Year, Cultivar, Location, and Storage Regime on Pecan Kernel Color

1998 ◽  
Vol 123 (4) ◽  
pp. 681-686 ◽  
Author(s):  
L.J. Grauke ◽  
T.E. Thompson ◽  
E.F. Young ◽  
H.D. Petersen
Keyword(s):  
Color Change ◽  
El Paso ◽  
Color Difference ◽  
Kernel Color ◽  
Color Differences ◽  
Color System ◽  
Different Temperatures ◽  
And Storage ◽  
Color Attribute ◽  
Over Time

The Munsell color system was used to study kernel color differences between four pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars (`Cheyenne', `Choctaw', `Western', and `Wichita') grown at four locations (Tulare, Calif., and Brownwood, Crystal City, and El Paso, Texas) during two seasons (1987 and 1988) and stored under different temperatures (20 to 24 °C and -5 °C). Kernel color changed over time from yellow to red hues and from lighter to darker values, but changed very little in chroma. Initial ratings of each color attribute by cultivar were positively correlated with patterns of change in that attribute over time. Kernels collected in 1987 were more yellow and had greater color saturation than kernels collected in 1988. `Cheyenne' kernels were the most yellow of the cultivars tested and `Wichita' kernels were the most red. `Cheyenne' kernels were lighter than those of any other cultivar. Kernels frozen 6 or 12 months were more red in hue than unfrozen kernels, but could not be distinguished on the basis of value (lightness). Kernels frozen 12 months had reduced chroma compared to those frozen 6 months or unfrozen. Shelled kernels of `Wichita' changed hue more in storage than kernels of other cultivars. Shelled kernels held at 20 to 24 °C became darker and developed red coloration quicker than unshelled pecans. Variation in hue and value accounted for the majority of color difference between cultivars. Changes in hue accounted for the majority of color change over time. Differences among cultivars in value (lightness) were consistent over time.

scholarly journals Spectrophotometric Evaluation of Color Changes of Bleach-shade Resin-based Composites after Staining and Bleaching

2014 ◽  
Vol 15 (5) ◽  
pp. 587-594 ◽  
Author(s):  
Rafat Ibrahim Farah ◽  
Hytham Elwi
Keyword(s):  
Color Change ◽  
Color Space ◽  
Color Stability ◽  
Light Activation ◽  
Carbamide Peroxide ◽  
Color Changes ◽  
Stain Removal ◽  
Storage Solutions ◽  
Color Differences ◽  
Level Of Significance

ABSTRACT Spectrophotometric evaluation of color changes of Bleachshade resin-based composites after staining and bleaching. Aim The aim of this study was to evaluate the color stability of two commercially available bleach-shade resin composites (RC) after exposure to 3 storage solutions and the effect of 3 bleaching agents on the color stability and stain removal from stained RC. Materials and methods Two bleach-shade RC were evaluated in this study, including a nanofilled RC, FiltekTM Z350 XT (FZ), and a nanohybrid RC, Tetric® N-Ceram (TC), in the extra-white body (shade) (XWB) and L shades, respectively. Twenty-seven disk-shaped specimens, each measuring 12 mm in diameter and 2 mm in thickness, were prepared for each RC, with a total of 54 specimens. Specimens were randomly allocated into 3 groups of 9 specimens each and immersed in 3 storage solutions (distilled water, tea and coffee) for 7 days period. The 9 specimens in each staining group were further divided into 3 subgroups. Specimens in each subgroup (n = 3) were bleached using one of the bleaching agents (10 and 16% Zoom NiteWhite amorphous calcium phosphate (ACP), and Zoom 2 chairside with light activation) for 5 days period. The specimen colors were measured with spectrophotometer. The measurements were performed on each sample three times at baseline, after staining, and after bleaching. Color was expressed using the commission international de I'Eclairage (CIE) L*a*b* color space. The color differences (ÄE) between the three measurements were calculated and the results were statistically analyzed using Two-way and Three-way analysis of variance (ANOVA) and Tukey's posthoc tests. Level of significance was set at p < 0.05. Results Tetric® N-ceram materials demonstrated significantly less color change than the FZ and the color change, which was greater after storage in coffee compared to tea, was statistically significant. The bleaching agents significantly influence the color changes of composite specimens. All groups showed (ÄE) values below 3.3 after bleaching, except for ‘Zoom 2 chairside’ with light activation groups, which is shown clinically unacceptable lighter shade (ÄE >3.3). Conclusion Bleach-shade composites showed significant discoloration (ÄE > 3.3) after being immersed into coffee and tea solutions. Nanofilled composites discolored more than nanohybrid composites, and carbamide peroxide-based bleaching agents were effective in reducing the discoloration to a clinically acceptable value (ÄE > 3.3). How to cite this article Farah RI, Elwi H. Spectrophotometric Evaluation of Color Changes of Bleach-shade Resin-based Composites after Staining and Bleaching. J Contemp Dent Pract 2014;15(5):587-594.

Effect of Bleaching on Color Change of Stained Resin Composites

2017 ◽  
Vol 751 ◽  
pp. 636-642
Author(s):  
Ratcha Raksakmanut ◽  
Ampaporn Nithipratheep ◽  
Ornjira Weeriyanan ◽  
Panida Pittayaporn ◽  
Waivich Komonpale ◽  
...  
Keyword(s):  
Red Wine ◽  
Color Change ◽  
Artificial Saliva ◽  
Resin Composites ◽  
Carbamide Peroxide ◽  
Spectrophotometric Measurement ◽  
Bleaching Process ◽  
Color Changes ◽  
Color Differences ◽  
Before And After

The aim of this study was to evaluate the effects of bleaching on color change of stained resin composites. Ninety disk-shaped specimens were prepared with 3 different composite materials (Estelite ∑ Quick, Premise, and Filtek Z350 XT). After stored in artificial saliva at 37°C for 24 hours in an incubator, the 30 specimens of each material were divided into 3 subgroups and immersed in either coffee, red wine, or artificial saliva (control) at 37°C. After 24 days, spectrophotometric measurement was performed. After the staining process, the bleaching agent (Opalescence, 10% carbamide peroxide) was applied to the surface of the specimens, 8 hours per day for 14 days. After the bleaching process, spectrophotometric measurement was performed. The color differences between specimens before and after bleaching were statistically significant (ΔE*ab>3.3) for all composites in the red wine staining. The highest-level color change after bleaching was observed for Filtek Z350 XT in red wine staining, while the least value was found in Estelite ∑ Quick in coffee staining. In summary, color changes of all red wine-stained composites after bleaching were noticeable and have higher level of color change than coffee-stained composites.

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