Purpose: To test whether the distance to the mass center of a buildup made of visible-light- or chemically curing composite resin bonded to dentin and cured in one increment has an influence on µTBS.
Materials And Methods: In the experimental groups, one-increment visible-light (Z250) or chemically-cured (TiCore) composite-resins buildups were bonded to flattened bovine dentin surfaces. In the control groups, the same materials were bonded as separate buildups on circumscribed areas to minimize the effect of shearing polymerization contraction. Compound composite/interface/dentin specimens were trimmed out of buildups and tested in tension until detachment; the distances to the mass centers of their respective buildups were recorded as the independent variable. The correlation between µTBS and distances was tested in each group. Slopes and intercepts of regression lines (µTBS to bonded area) were compared in the experimental groups.
Results: The correlation between µTBS and distances was negative and statistically significant for both experimental groups (p < 0.0001), but not for the two control groups (p > 0.34).
Conclusion: In clinical situations such as direct resin veneering or resin core construction, where a first layer of a light- or chemically cured resin composite is bonded and cured on a broad surface, the µTBS of the interface decreases proportionally to the distance to the mass center of the restoration.
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http://dx.doi.org/10.3290/j.jad.a27797 | DOI Listing |
J Am Chem Soc
January 2025
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
A prevalent challenge in particulate photocatalytic water splitting lies in the fact that while numerous photocatalysts exhibit outstanding hydrogen evolution reaction (HER) activity in organic sacrificial reagents, their performance diminishes markedly in a Z-scheme water splitting system using electronic mediators. This underlying reason remains undefined, posing a long-standing issue in photocatalytic water splitting. Herein, we unveiled that the primary reason for the decreased HER activity in electronic mediators is due to the strong adsorption of shuttle ions on cocatalyst surfaces, which inhibits the initial proton reduction and results in a severe backward reaction of the oxidized shuttle ions.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
Electrochemical nitrogen conversion for ammonia (NH) synthesis, driven by renewable electricity, offers a sustainable alternative to the traditional Haber-Bosch process. However, this conversion process remains limited by a low Faradaic efficiency (FE) and NH yield. Although transition metals have been widely studied as catalysts for NH synthesis through effective electron donation/back-donation mechanisms, there are challenges in electrochemical environments, including competitive hydrogen evolution reaction (HER) and catalyst stability issues.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Hydrogen spillover is an important process in catalytic hydrogenation reactions, facilitating H activation and modulating surface chemistry of reducible oxide catalysts. This study focuses on the unveiling of platinum-induced hydrogen spillover on monoclinic tungsten trioxide (γ-WO), employing ambient pressure X-ray photoelectron spectroscopy, density functional theory calculations and microkinetic modeling to investigate the dynamic evolution of surface states at varied temperatures. At room temperature, hydrogen spillover results in the formation of W and hydrogen intermediates (hydroxyl species and adsorbed water), facilitated by Pt metal clusters.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Chinese Academy of Sciences Dalian Institute of Chemical Physics, State Key Laboratory of Catalysis, 457 Zhongshan Road, 116023, Dalian, CHINA.
The reduction of CO2 to CO provides a promising approach to the production of valuable chemicals through CO2 utilization. However, challenges persist with the rapid deactivation and insufficient activity of catalysts. Herein, we developed a soft-hard dual-template method to synthesize layered MoS2 using inexpensive and scalable templates, enabling facile regulation of sulfur vacancies by controlling the number of layers.
View Article and Find Full Text PDFAnal Methods
November 2017
Anhui Key Laboratory of Chemo-Biosensing, Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China.
A new aptamer-based surface plasmon resonance (SPR) system has been designed to detect Hg that utilizes near-infrared (NIR)-to-NIR gold nanoparticle coated NaYF:Yb,Tm,Gd up-conversion nanoparticles (AuNPs@NaYF:Yb,Tm,Gd UCNPs) as probes. The AuNPs@NaYF:Yb,Tm,Gd UCNPs were prepared and excited by near-infrared light (980 nm) which emitted at a near-infrared wavelength (808 nm) using an inexpensive infrared continuous wave laser diode. The AuNPs@NaYF:Yb,Tm,Gd UCNPs were conjugated with Hg aptamers.
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