The light-attenuating effects of enamel on the mechanical properties of light-cured composite resins were evaluated using simple experimental filters. Three filters were designed to simulate the light transmittance characteristics of 0.5, 1.0, and 1.5 mm thick human enamel. The Knoop hardness numbers (KHN) and the elastic modulus in transverse tests for twelve shades of three light-cured composite resins were examined. These resins were cured either using direct irradiation with a light source, or indirect irradiation through one of the filters. The attenuations of light by 0.5, 1.0, and 1.5 mm thick enamel filter were 45%, 67% and 81% in the 430 nm-550 nm wavelength region, respectively. For all materials, KHN and the elastic modulus of specimens irradiated through filters were significantly lower than those irradiated directly. The results suggest that the light-attenuating effect of enamel reduces the mechanical properties of light-cured resin, and may cause poor clinical longevity of restorations.
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http://dx.doi.org/10.4012/dmj.21.147 | DOI Listing |
ACS Nano
January 2025
School of Engineering, RMIT University, 124 La Trobe Street, Melbourne, Victoria 3001, Australia.
Modern-day applications demand onboard electricity generation that can be achieved using piezoelectric phenomena. Reducing the dimensionality of materials is a pathway to enhancing the piezoelectric properties. Transition-metal dichalcogenides have been shown to exhibit high piezoelectricity.
View Article and Find Full Text PDFDiscov Nano
January 2025
National Nanotechnology Laboratory for Agriculture (LNNA), Embrapa Instrumentação, 1452 XV de Novembro St., São Carlos, SP, 13560-970, Brazil.
Multifunctional membranes applied to biomedical materials become attractive to support the biological agents and increase their properties. In this study, biopolymeric fibers based on polycaprolactone (PCL) and pectin (PEC) were reinforced with faujasite zeolite (FAU) for cloxacillin antibiotic (CLX) loading. FAU with a high specific surface area (347 ± 8 m g), high crystallinity and particles with a diameter of up to 100 nm were produced under optimized synthesis conditions (100 °C/4 h).
View Article and Find Full Text PDFArterial compliance (AC) is an important cardiovascular parameter characterizing mechanical properties of arteries. AC is significantly influenced by arterial wall structure and vasomotion, and it markedly influences cardiac load. A new method, based on a two-element Windkessel model, has been recently proposed for estimating AC as the ratio of the time constant T of the diastolic blood pressure decay and peripheral vascular resistance derived from clinically available stroke volume measurements and selected peripheral blood pressure parameters which are less prone to peripheral distortions.
View Article and Find Full Text PDFBiomater Sci
January 2025
Department of Chemistry, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam, India.
Hydroxyapatite (HA), the main inorganic bone component, is the most widely researched bioceramic for bone repair. This paper presents a comprehensive review of recent advancements in HA synthesis methods and their integration into additive manufacturing (AM) processes. Synthesis methodologies discussed include wet, dry, and biomimetic routes, emphasizing their impact on tailoring the physicochemical properties of HA for biomedical applications.
View Article and Find Full Text PDFJ Exp Bot
January 2025
Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, 24118 Kiel, Germany.
Several plant seeds release a mucilaginous envelope through hydration, rich in pectins and stabilized by cellulose fibers. This mucilage aids in seed protection, development, and adhesion for dispersal. This study aimed to separate the effects of pectins and cellulose fibers by using pectinase to remove mucilage pectins, leaving cellulose arrays, and performing wet and dry pull-off force measurements on seeds of three plant species: Salvia hispanica (Chia), Collomia grandiflora (Collomia) and Linum usitatissimum (Flax).
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