Objectives: The aim of the investigation was to evaluate the effects of surface mechanical treatments of all-Y-TZP restorations. In order to do that, surface roughness (Rs), fractal dimension (Df), fracture toughness (Ft), Vickers hardness (Hv), crack length (Cl), and opening (Co) were determined.
Materials And Methods: Y-TZP bar-shaped specimens (n = 30) were subdivided into three groups: as received by milling center (M), after coarse polishing (CP), and after fine polishing (FP). The specimens were examined under both confocal laser and electron scanning microscopes. One-way ANOVA and post hoc tests were used to analyze the data (α = 0.05).
Results: The FP group showed a significantly lesser amount of Rs (P < 0.05). The Df analysis confirmed the significantly lesser amount of surface complexity within the FP group (P < 0.05). The Hv values were not significantly different among the groups. The Ft was significantly lesser within the FP group (P < 0.05). At the same time, both Cl and Co were significantly higher within the FP group (P < 0.05). Likewise, the FP treatment showed a significant decrease in roughness and surface complexity associated to a decrease of fracture toughness with a significant microcrack increase.
Conclusions: The present study suggests that the fine polishing procedure in all-YTZP restorations produces surface embrittlement.
Clinical Relevance: Because of the surface embrittlement, mechanical surface polishing of all-zirconia restorations should be avoided.
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http://dx.doi.org/10.1007/s00784-013-1018-z | DOI Listing |
Heliyon
January 2025
AU-Sophisticated Testing and Instrumentation Centre (AU-STIC), CoE-Advanced Materials Synthesis (CoE-AMS), Department of Mechanical Engineering, Alliance School of Applied Engineering, Alliance University, Bengaluru, 562106, India.
A consistent research attempt to develop newer lightweight-high strength materials facilitates the automobile sector to excel in product efficiency. The present research is another endeavour to anchor the automobile industries by exploring novel composite. The different earth elements SiC and YO are utilised for the hybrid reinforcement of Al 5052 alloy in four different weight proportions.
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January 2025
College of Materials Science & Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
Developing hydrogels with high conductivity and toughness a facile strategy is important yet challenging. Herein, we proposed a new strategy to develop conductive hydrogels by growing metal dendrites. Water-soluble Sn ions were soaked into the gel and then converted to Sn dendrites an electrochemical reaction; the excessive Sn ions were finally removed by water dialysis, accompanied by dramatic shrinkage of the gel.
View Article and Find Full Text PDFSci Rep
January 2025
Advanced Glass and Glass Ceramic Research Laboratory, Department of Physics, University of Lucknow, Lucknow, 226007, India.
Recently, 3-D porous architecture of the composites play a key role in cell proliferation, bone regeneration, and anticancer activities. The osteoinductive and osteoconductive properties of β-TCP allow for the complete repair of numerous bone defects. Herein, β-TCP was synthesized by wet chemical precipitation route, and their 3-D porous composites with HBO and Cu nanoparticles were prepared by the solid-state reaction method with improved mechanical and biological performances.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
January 2025
School of Materials Science and Engineering, University of Jinan, Jinan, 250022, China. Electronic address:
Silicon nitride (Si₃N₄) ceramics exhibit excellent mechanical properties and biocompatibility, making them highly suitable for biomedical applications, particularly in implants. In this study, the mechanical properties and bioactivity of Si₃N₄ ceramics with varying amounts of Y₂O₃-Al₂O₃-SiO₂ sintering aids were investigated. Increasing the sintering additive content from 4 wt% to 8 wt% substantially improved the bulk density of the ceramics, leading to notable enhancements in mechanical properties.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia.
In this work, the fracture mechanism of winding carbon-fiber-reinforced plastics (CFRPs) based on epoxy matrices reinforced by polysulfone film was investigated. Two types of polymer matrices were used: epoxy oligomer (EO) cured by iso-methyltetrahydrophthalic anhydride (iso-MTHPA), and EO-modified polysulfone (PSU) with active diluent furfuryl glycidyl ether (FGE) cured by iso-MTHPA. At the winding stage, the reinforcing film was placed in the middle layer of the CFRP.
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