Colour And The Optical Properties Of Materials:...
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Colour is an important and integral part of everyday life, and an understanding and knowledge of the scientific principles behind colour, with its many applications and uses, is becoming increasingly important to a wide range of academic disciplines, from physical, medical and biological sciences through to the arts. Colour and the Optical Properties of Materials carefully introduces the science behind the subject, along with many modern and cutting-edge applications, chose to appeal to today's students. For science students, it provides a broad introduction to the subject and the many applications of colour. To more applied students, such as engineering and arts students, it provides the essential scientific background to colour and the many applications. Features: * Introduces the science behind the subject whilst closely connecting it to modern applications, such as colour displays, optical amplifiers and colour centre lasers * Richly illustrated with full-colour plates * Includes many worked examples, along with problems and exercises at the end of each chapter and selected answers at the back of the book * A Web site, including additional problems and full solutions to all the problems, which may be accessed at: www.cardiff.ac.uk/uwcc/engin/staff/rdjt/colour Written for students taking an introductory course in colour in a wide range of disciplines such as physics, chemistry, engineering, materials science, computer science, design, photography, architecture and textiles.
Considering that the processes of PEEK discoloration caused by either intrinsic or extrinsic factors require elucidation, the aim of this study was to investigate the long-term effect of the combined action of ageing and immersing solutions on the optical properties and color stability of PEEK material, related to surface processing (polishing or glazing). (2) Methods: This study aims to determine the influence of different ageing and staining protocols on optical properties, color changes, and surface roughness of a reinforced PEEK material (bioHPP, Bredent, Senden, Germany). For ageing, specimens were submitted to 5000 cycles in a 55 C bath and a 5 C bath filled with distilled water. For staining, thermal cycling was performed in a hot coffee bath (55 C) and a bath filled with distilled water (37 C) and in a cold juice bath (5 C) and a bath filled with distilled water (37 C). Translucency (TP) and opalescence (OP) parameters were determined, the total color change value (ΔΕ*) was calculated, specimens' surface roughness was analyzed, and statistical analyses were performed. (3) Results: The mean TP values of the studied samples were in the interval of 1.25-3.60, which is lower than those reported for natural teeth or other aesthetic restoration materials. The OP values of PEEK were registered in the range of 0.27-0.75, being also lower than those of natural teeth or other aesthetic restoration materials. OP has a very strong positive relationship with TP. The mean registered Ra values for all subgroups were below 0.13 µm. Artificial ageing and staining in hot coffee proved to increase the roughness values. (4) Conclusions: The glazing of PEEK has a favorable effect on surface roughness and opalescence, irrespective of the artificial ageing or staining protocols. Artificial ageing damages the color stability and roughness of PEEK, regardless of surface processing, and decreases the translucency and opalescence of glazed surfaces. Immersion in hot coffee leads to perceivable discolorations.
The optical properties of a material define how it interacts with light. The optical properties of matter are studied in optical physics, a subfield of optics. The optical properties of matter include:
From our independent perspective, we expertly analyse a range of optical properties, delivering accurate information which helps to achieve the desired aesthetics during development, production or in the end-use application.
During production, various steps such as colouration, heat treatment and mechanical processing can affect optical properties. Through our testing programs - including fundamental tests such as Gloss, Haze, Birefringence and Ultra-Violet and Visable (UV/VIS) light absorption and transmission - Intertek can help you to optimise production in order to achieve optical property specifications.
Our polymer scientists understand that the optical properties of polymers are closely related to the chemical microstructure, thermal and physical properties of these materials, and as such, providing comprehensive expertise which spans chemical, thermal plus physical and mechanical testing. Our industry application experts take you beyond the test result, applying their experience and knowledge to gain improvement of a material's optical properties.
Intertek's scientists understand that the optical properties of polymers are closely related to the chemical microstructure, thermal and physical properties of these materials, and as such, we provide comprehensive expertise that covers chemical, physical, mechanical and thermal testing. Our industry application experts take you beyond the test result, using their experience and knowledge to provide the guidance you need to achieve improvement of a material's optical properties.
This is the second article in a three-part series that reviews the thermal, optical, and mechanical properties of glass. We will define common glass properties and explain their application and importance in component design.
The optical properties of a material determine how it will interact with light. Today, most engineers use advanced software tools to simulate the properties of a material and their impact on optical performance. Still, familiarity with a few fundamental optical properties will help engineers pick the right material for their application. In this article, we review refractive index, transmission, absorption, and wavelength dependency and discuss how these properties impact product design.
The reporting of transmittance values of a material can vary depending on the application or common industry nomenclature. While most industrial glasses report optical properties as external transmittance, values for filter glasses are typically given as internal transmittance. This is because filter glasses may be treated with anti-reflective coatings to prevent intensity losses at the glass surface. For example, a glass filter which has an external transmission of 92% at 589.2 nm might have a much higher internal transmittance of 0.98, as is the case with our 3131 filter.
Colour stability of microhybrid and nanohybrid/nanofilled composites has been tested in a variety of clinically relevant scenarios, including the effects of surface coating24, underlying dentine replacement material25, bleaching agents26, mouth rinses27,28, coloured food29 and beverages30,31,32. Similarly, glass ionomer cements (GICs) were tested for staining after exposure to coloured beverages27 but no data was found for mouth rinses. A recent meta-analysis has reported on staining potential of a number of commercially available mouthwashes on dental composites33. However, literature lacks data on the effect of CHX and, particularly, bioflavonoid complex (Citrox)-containing mouth rinses on optical properties (colour and translucency) of composites and GICs for direct restorations.
Differences in ΔTP00 of the tested materials following exposure to mouth rinses were both material- and medium-dependent. ΔTP00 did not follow the same pattern as ΔE00 and no correlation between the two properties was established. TP is expressed as the relative amount of light passing through material and obtained by calculating colour difference of specimen against the white and black backgrounds35. Translucency is related to two aspects of light interaction with material (absorption and scattering) and factors such as surface topography, filler type and volume and refractive index mismatch between fillers and resin matrix have a significant effect19. Refractive index mismatch is known to change during polymerization as monomers convert to polymers but also after aging due to hydrolytical changes16. The present results indicate unpredictable effects of mouth rinses on ΔTP00 of restorative materials, that are both medium- and material-dependent.
The purpose of this study was to evaluate the optical properties of nanohybrid Grandio (GR) and nanoceramic Lava Ultimate (LU) CAD/CAM restorative materials subjected to different beverage solutions and subsequently bleached.
LU nanoceramic CAD/CAM restorative material revealed higher color changes than GR nanohybrid material. Staining beverage solutions had a distinct influence on the optical properties of the tested CAD/CAM restorative materials.
There is no data available about the effect of staining beverages and bleaching agents on the optical properties of CAD/CAM Grandio nanohybrid restorative material. The aim of this study was to evaluate the color change, translucency, and whiteness index of CAD/CAM nanohybrid and nanoceramic restorative materials subjected to staining beverages and subsequently bleached. The null hypothesis of the study was that there was no difference in stain susceptibility, translucency changes, and whiteness index between the two CAD/CAM restorative materials; GR nanohybrid and LU nanoceramic, after staining with beverage solutions and bleaching.
It is important to evaluate the optical properties of newly developed CAD/CAM restorative materials for expecting the durability of the esthetic characteristic of restorations . The consumption of different daily beverages exposes teeth and restorations to staining, which might affect the esthetic properties of restorative materials [14, 25]. Due to esthetics demand, bleaching treatment became a routine practice for the patients and throughout the bleaching process, the existing restorations are exposed to bleaching agent . Superficial staining with beverages can be removed by bleaching [18, 26]. However, if the discoloration includes deeper layers, bleaching is no longer effective, and replacement of restoration should be considered . 59ce067264