Effect of addition of cellulose nanocrystals to wood coatings on color changes and surface roughness due to accelerated weathering

2014 ◽  
Vol 12 (2) ◽  
pp. 247-258 ◽  
Author(s):  
Vahe Vardanyan ◽  
Tigran Galstian ◽  
Bernard Riedl
Keyword(s):  
Surface Roughness ◽  
Cellulose Nanocrystals ◽  
Accelerated Weathering ◽  
Color Changes ◽  
Wood Coatings

scholarly journals Influence of Mechanical and Chemical Degradation in the Surface Roughness, Gloss, and Color of Microhybrid Composites

2017 ◽  
Vol 18 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Cleidiel AA Lemos ◽  
Silvio J Mauro ◽  
Paulo H dos Santos ◽  
André LF Briso ◽  
Ticiane C Fagundes
Keyword(s):  
Surface Roughness ◽  
Clinical Significance ◽  
Composite Resin ◽  
Color Change ◽  
Wilcoxon Test ◽  
Chemical Degradation ◽  
Color Changes ◽  
Final Data ◽  
Properties Of Materials ◽  
Spearman Test

ABSTRACT Aim The aim of this study was to investigate the association of different degradations on the roughness, gloss, and color changes of microhybrid composites. Materials and methods Ten specimens were prepared for Charisma, Amelogen Plus, Point 4, and Opallis resins. Surfaces were polished and baseline measurements of roughness, gloss, and color were recorded. Specimens were then submitted to chemical and mechanical challenges, and the specimens were reevaluated. Roughness and gloss were analyzed by Kruskal – Wallis and Dunn's test (p < 0.05). Color change (ΔE) was analyzed by one-way analysis of variance and Tukey's tests (p < 0.05). The initial and final data were compared using the Wilcoxon test (p < 0.05). Spearman test checked the correlation between the roughness and gloss (p < 0.05). Results Regarding surface roughness and gloss, there was no difference between composites before challenges. However, all composites showed a significant increase of roughness after challenges, with highest values for Charisma. The gloss was influenced by challenges, evidencing the best gloss for Point 4. Charisma showed the highest value of color change. There was no correlation between surface roughness and gloss for the initial analysis, and after the challenges. Conclusion Composites were influenced by association of challenges, and Charisma showed the highest changes for roughness, gloss, and color. Clinical significance The type of composite resin influenced the properties of materials, which are surface roughness, gloss, and color change. The dentist should be aware of the performance of different brands, to choose the correct required composite resin for each type of patient or region to be restored. How to cite this article Lemos CAA, Mauro SJ, dos Santos PH, Briso ALF, Fagundes TC. Influence of Mechanical and Chemical Degradation in the Surface Roughness, Gloss, and Color of Microhybrid Composites. J Contemp Dent Pract 2017;18(4):283-288.

scholarly journals In Situ Performance Assessment and Evaluation of Hydrophobic and Ultraviolet Protective Treatments for Historic Log Structures

2015 ◽  
Vol 38 ◽  
pp. 100-111
Author(s):  
Courtney Magill ◽  
Frank Matero
Keyword(s):  
Field Research ◽  
Accelerated Weathering ◽  
Assessment And Evaluation ◽  
Appropriate Treatment ◽  
Wood Coatings ◽  
Subsequent Phase ◽  
Initial Results ◽  
Ongoing Project

Beginning in the summer of 2015, research was conducted on protective wood coatings and accelerated weathering testing methods for architectural log and timber. A rack for supplementary natural weathering testing of hydrophobic and ultraviolet protective surface treatments for logs was also erected as a subsequent phase at Grand Teton National Park. This laboratory and field research is part of an ongoing project to develop an appropriate treatment for historic log structures in the region that will preserve their original fabric while maintaining the intended historic appearance of the buildings, i.e., unpainted. The weathering rack will be in place for upwards of five years to verify the lab-based results from Phase I and to determine the long-term durability of the chosen treatments on already aged materials in situ. This report addresses the methods and materials for preparation of the weathering rack and samples as well as the methods being used to monitor their progress and initial results. Readings will be taken yearly to monitor the effects of weathering on each treatment.

scholarly journals Effect of In-Office Bleaching on Color and Surface Roughness of Composite Restoratives

2010 ◽  
Vol 04 (02) ◽  
pp. 118-127 ◽  
Author(s):  
Randa Hafez ◽  
Doa Ahmed ◽  
Mai Yousry ◽  
Wafa El-Badrawy ◽  
Omar El-Mowafy
Keyword(s):  
Surface Roughness ◽  
Surface Texture ◽  
Color Change ◽  
Distilled Water ◽  
Bleaching Agent ◽  
Color Changes ◽  
Before And After ◽  
Colorimetric Measurements ◽  
Natural Teeth ◽  
Environmental Sem

Objectives: The purpose of this study was to determine color changes and surface roughness of composites when they were subjected to in-office bleaching.Methods: 12 discs 15 mm in diameter and 2 mm thick were prepared from two shades (A2 & A4) of two composites, Durafil VS (DF) and TPH3 (TPH). Specimens were polished and stored in distilled water for 24 hours at 37°C before being subjected to bleaching, staining, and re-bleaching. Each of the groups of specimens (DF-A2, DF-A4, TPH-A2 and TPH-A4) were subdivided into three subgroups (n=4) and bleached with Beyond, LumaWhite-Plus, and Opalescence-Boost. Specimens were then stained by immersing them in a coffee solution for 48 hours at 37°C, and then they were re-bleached. Colorimetric measurements were performed at baseline, after bleaching, after staining, and after rebleaching. Surface roughness was determined with environmental SEM before and after bleaching. Data were statistically-analyzed.Results: None of the bleaching systems notably changed the color of composites (delta-E<2). Coffee staining affected DF specimens more than TPH. Stained specimens showed variable responses to whitening with no significant color change observed with TPH (delta-E<2) and significant changes observed with DF. Surface roughness significantly changed with bleaching, but the degree varied according to composite shade and bleaching agent.Conclusions: Three in-office bleaching agents had no significant color changes on two composites. DF showed more color change than TPH when immersed in coffee. Stained composites showed different degrees of whitening, with DF showing more response. Bleaching may adversely affect the surface texture of composites. Dentists should take into consideration that composite restorations may not respond to bleaching in the same way that natural teeth do. (Eur J Dent 2010;4:118-127)

Accelerated Weathering of Modified Wood Flour Plastic Composites

2007 ◽  
Vol 29-30 ◽  
pp. 315-318 ◽  
Author(s):  
J.S. Fabiyi ◽  
A.G. McDonald
Keyword(s):  
Color Change ◽  
Wood Flour ◽  
Wood Fiber ◽  
Color Measurement ◽  
Accelerated Weathering ◽  
Wood Fibers ◽  
Pyrolysis Gas ◽  
Color Changes ◽  
Plastic Composites ◽  
Gas Chromatograph Mass Spectrometry

The effect of accelerated weathering on the chemical and color of wood plastic composites (WPC) made from modified pine wood fiber (control, extractives free and holocellulose) was investigated. WPC were produced from the various wood fibers (60%, weight) and high density polyethylene (40%, weight) as matrix were subjected to accelerated weathering in xenon-arc weatherometer for up to 1200 hours. This study aimed at getting a better understanding of the chemical changes that occur to weathered WPC relative to its material compositions (wood and plastic). Chemical analyses and color measurement of the weathered surface using Fourier transform infrared (FTIR) spectroscopy, pyrolysis gas chromatograph mass spectrometry and colorimetery showed that degradation of WPC had occurred, causing color changes. It was observed that WPC made from holocellulose wood fiber had the lowest color change compared to extractives free wood and control wood fiber based WPC.

Surface roughness and color characteristics of wood treated with preservatives after accelerated weathering test

2005 ◽  
Vol 250 (1-4) ◽  
pp. 35-42 ◽  
Author(s):  
Ali Temiz ◽  
Umit C. Yildiz ◽  
Ismail Aydin ◽  
Morten Eikenes ◽  
Gry Alfredsen ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Accelerated Weathering ◽  
Color Characteristics ◽  
Accelerated Weathering Test

scholarly journals Influence of surface roughness on color changes in building stones

2003 ◽  
Vol 28 (5) ◽  
pp. 343-351 ◽  
Author(s):  
D. Benavente ◽  
F. Martínez-Verdú ◽  
A. Bernabeu ◽  
V. Viqueira ◽  
R. Fort ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Building Stones ◽  
Color Changes

Color Stability of Heat-Treated Okan Sapwood during Artificial Weathering

2011 ◽  
Vol 197-198 ◽  
pp. 13-16
Author(s):  
Qiang Shi ◽  
Jing Hui Jiang
Keyword(s):  
Treated Wood ◽  
Untreated Wood ◽  
Color Stability ◽  
Accelerated Weathering ◽  
Experimental Conditions ◽  
Color Changes ◽  
Heat Treated ◽  
Series Of Experiments ◽  
Xenon Light ◽  
Photo Stability

This study describes experiments of testing the color stability of heat-treated okan sapwood samples. Heat-treatment was done at 160°C,180°C,200°C,220°C during 4 hours, under steam. series of experiments were carried out to investigate the color stability of heat-treated okan sapwood compared to untreated wood during 100 hours xenon light irradiation. Color measurements during accelerated weathering were made at intervals throughout the test period. The results are presented in △E* and L* a* b*coordinates according to the CIE(1976)L*a*b* parameters color system. Better photo-stability in terms of color changes was recorded for heat-treated wood compared to the untreated one. The properties of heat treated wood are involved in the heat-treated wood resistanceagainst xenon light under experimental conditions.

scholarly journals Can ozone or violet light improve the color change or physicochemical properties of hydrogen peroxide-bleached tooth?

2021 ◽  
Vol 32 (4) ◽  
pp. 19-30
Author(s):  
Nayara Rodrigues Nascimento Oliveira Tavares ◽  
Alexia da Mata Galvão ◽  
Lia Dietrich ◽  
Roberta Furtado Carvalho ◽  
Robinson Sabino Silva ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Roughness ◽  
Color Change ◽  
Repeated Measure ◽  
Color Changes ◽  
Violet Light ◽  
Atomic Force ◽  
Measure Anova ◽  
Before And After ◽  
To Receive

Abstract: This study investigated the bleaching effectiveness and the physicochemical effects on enamel of violet light and ozone, associate or not to hydrogen peroxide, compared to 35%-hydrogen peroxide. Enamel-dentin blocks from human molars were randomly allocated to receive one of the following bleaching protocols (n=15): (HP) 35%-hydrogen peroxide, (VL) violet light, (OZ) ozone, the association between hydrogen peroxide with ozone (OZ+HP) or violet light (VL+HP). All protocols were performed in two sessions with a 48h interval. Color (spectrophotometer) and mineral composition (Raman spectroscopy) were measured before and after the bleaching. Color changes were calculated by ΔEab, ΔE00, and whitening index (WI). The surface roughness was measured with an atomic force microscope. Data were analyzed by One-way or Two-way repeated measure ANOVA followed by the Tukey’s test (α = 0.05). The lowest color change values (either measured by WI, ΔEab, or ΔE00) were observed for VL and OZ used with no HP. Violet light associate with HP was unable to improve the color changes observed for the peroxide alone, in combination with OZ and HP, the highest color changes were verified. Regardless of bleaching protocol, the bleached enamel presented higher contents of PO4 and CO3 -2 than those observed at baseline. All bleaching protocols resulted in similar enamel surface roughness. Both the VL and the OZ caused reduced effects on the enamel color change when used alone. The ozone therapy improved the bleaching effect in the group that received the association of HP.

scholarly journals Nonprescription Bleaching versus Home Bleaching with Professional Prescriptions: Which One is Safer? A Comprehensive Review of Color Changes and Their Side Effects on Human Enamel

2019 ◽  
Vol 13 (04) ◽  
pp. 589-598
Author(s):  
Farhana Omar ◽  
Zuryati Ab-Ghani ◽  
Normastura Abd Rahman ◽  
Mohamad Syahrizal Halim
Keyword(s):  
Surface Roughness ◽  
Over The Counter ◽  
Microscopic Appearance ◽  
Significance Level ◽  
Force Microscopy ◽  
Colorimetric Measurement ◽  
Color Changes ◽  
Atomic Force ◽  
Human Enamel ◽  
Before And After

Abstract Objectives This study evaluates the efficacy and safety of the professionally prescribed and nonprescription over-the-counter (OTC) bleaching agents. Materials and Methods Extracted human upper central incisors were prepared and stained with red wine for 14 days before being subjected to four different bleaching agents: professionally prescribed opalescence PF 15%, VOCO Perfect Bleach 10%, nonprescription OTC Crest 3D Whitestrips, and Whitelight Teeth Whitening System. Colorimetric measurement was performed with Vita Easyshade Handheld Spectrophotometer, enamel surface microhardness measured using Vickers Hardness machine, and surface roughness was evaluated with profilometer, before and after bleaching. Scanning electron microscope (SEM) evaluation and atomic force microscopy were conducted postbleaching. Statistical Analysis The data were analyzed with t-test, two-way ANOVA, one-way ANOVA, and Turkey’s test at a significance level of 5%. Results All bleaching products have the same efficacy to whiten stained enamel. Opalescence PF 15% showed significant increase in the microhardness (92.69 ± 68.316). All groups demonstrated significant increase in surface roughness (p < 0.05). SEM evaluation showed that Opalescence PF 15% resulted in same microscopic appearance as unbleached enamel, while VOCO Perfect Bleach 10%, Whitelight Teeth Whitening System and Crest 3D Whitestrips demonstrated mild to moderate irregularities and accentuated irregularities, respectively. Conclusion Professionally prescribed bleaching agent of Opalescence PF 15% is effective tin whitening the teeth, while the other bleaching products may be effective but also have deleterious effects on the enamel.

scholarly journals The Effect of Different Storage Conditions on the Physical Properties of Pigmented Medical Grade I Silicone Maxillofacial Material

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ayman A. Al-Dharrab ◽  
Seham B. Tayel ◽  
Mona H. Abodaya
Keyword(s):  
Surface Roughness ◽  
Physical Properties ◽  
Storage Conditions ◽  
Sem Analysis ◽  
Prosthetic Material ◽  
Control Group ◽  
Color Changes ◽  
Group I ◽  
Significant Difference ◽  
Before And After

Objective. This study aimed to evaluate the effect of different storage solutions that simulate acidic, alkaline, and sebum conditiions on the physical properties of pigmented (colorant elastomer) cosmesil M511 maxillofacial prosthetic material. Materials and Methods. Sixty specimens were prepared according to the manufacturer's instructions and were tested before and after immersion of different storage conditions for six months at 37 °C. The following tests were performed: color changes (group I), solution absorption (group II), surface roughness (group III), and scanning electron microscopy (group IV). Results. There were no significant changes observed in the color and solution absorption tests while surface roughness revealed significant difference between control group and other testing storage medium groups, and this result was supported by SEM analysis that revealed limited surface changes. Conclusions. Cosmaseil material is an acceptable cross-linked formulation that withstands storage in different solutions with variable pH. The addition of pigment cannot vary the physical properties of these materials. Surface roughness test as well as SEM microscopic study showed moderate changes indicating a limited effect on the surface of the material.

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