Objectives: The aim of this study was to determine the phase transformation and the influence of aging on the flexural strength of different colored zirconia. The effect of hydrothermal aging in an autoclave was compared with the effect of mechanical stress by simulating chewing.
Methods: High-strength zirconia (3Y-TZP) was investigated in three different colors: uncolored, A3, and D3. Disc-shaped specimens (N = 3) were analyzed by X-ray diffraction (XRD), and flexural strength was determined on bar-shaped specimens (N = 15) in a 4-point bending test before and after performing two different aging protocols: aging in an autoclave (134 °C, 70 h) and aging in a chewing simulator (5 kg load, 1.2 million cycles). During autoclave aging, the fraction of monoclinic phase on the surface was determined every 5 h. Once this exceeded 25 vol%, aging of the bar specimens was stopped.
Results: While in the unstained group the mean value of the proportion of monoclinic phase already exceeded 25 vol% after 30 h in the autoclave, this was the case in both stained groups only after 70 h. No measurable phase transformation could be detected after chewing simulation. Only color A3 showed a statistically significant (p ≤ 0.05) decrease in flexural strength after aging in the chewing simulator.
Significance: The colored zirconia showed a higher resistance to phase transformation through hydrothermal aging. The metal oxides in the staining solutions are assumed to hinder the phase transformation in the zirconia. Therefore, the significant reduction in the stained zirconia after chewing simulation is particularly interesting.
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http://dx.doi.org/10.1016/j.dental.2023.06.005 | DOI Listing |
Sci Rep
January 2025
Department of Mathematics, Birla Institute of Technology and Science Pilani, Pilani Campus, Pilani, Rajasthan, 333031, India.
As India's population grows and urbanization accelerates, energy demand is increasing sharply while conventional sources fall behind. To tackle energy shortages and climate change, India must prioritize renewable energy sources (RES), which offer sustainable solutions. The country is rich in RES, which can enhance fuel mix for electricity generation.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Chemical Engineering, School of Engineering and Digital Science, Nazarbayev University, Astana 010000, Kazakhstan.
The escalating global energy demand necessitates enhanced oil recovery methods, particularly offshore. Biological nanotechnology offers sustainable, environment-friendly, and cost-effective alternatives to synthetic chemicals. This study explored the synthesis of polysaccharide-based nanoparticles (PNPs) from Corchorus olitorius leaves using a weak acid-assisted ultrasonic method and their application as nanocomposites for oil recovery.
View Article and Find Full Text PDFSci Total Environ
January 2025
Institute of Catalysis for Energy and Environment, College of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang 110034, China; State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Chang Ping, Beijing 102249, China.
The transformation and risk assessment of flavonoids triggered by free radicals deserve extensive attention. In this work, the degradation mechanisms, kinetics, and ecotoxicity of kaempferol and quercetin mediated by ∙OH, ∙OCH, ∙OOH, and O in gaseous and aqueous environments were investigated using cell experiments and quantum chemical calculations. Three radical scavenging mechanisms, including hydrogen atom transfer (HAT), radical adduct formation (RAF) and single electron transfer (SET) were discussed.
View Article and Find Full Text PDFAppl Biochem Biotechnol
January 2025
Ethnopharmacology and Algal Biotechnology Laboratory, Department of Botany, School of Life Sciences, Periyar University, Salem, Tamil Nadu, 636011, India.
In this present investigation, plant-mediated synthesis of titanium oxide (TiO) nanoparticles was synthesized from seagrass (Thalassia hemprichi) using the hot plate combustion method (HPCM). Synthesized TiO nanoparticles optical, functional, structural, and morphology properties were analyzed by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). SEM analysis confirmed the spherical shape of the TiO nanoparticles were observed in various sizes, viz.
View Article and Find Full Text PDFBMC Pharmacol Toxicol
January 2025
Biochemistry Department, Faculty of Science, Tanta University, Tanta, Egypt.
Background: Naringenin, a flavonoid compound found in citrus fruits, possesses valuable anticancer properties. However, its potential application in cancer treatment is limited by poor bioavailability and pharmacokinetics at tumor sites. To address this, Naringenin nanoparticles (NARNPs) were prepared using the emulsion diffusion technique and their anticancer effects were investigated in HepG2 cells.
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