The purpose of this study was to introduce a novel and simple method of evaluating the crystal length and crystalline content of lithium disilicate dental ceramics using images obtained from scanning electron microscopy (SEM) and analyzed with ImageJ (NIH) processing software. Three evaluators with varying experience levels assessed the average crystal length and percentage of crystalline content in four commercial lithium disilicate reinforced glass ceramic materials: IPS e.max (Ivoclar Vivadent), Rosetta SM (Hass), T-Lithium (Talmax), and IRIS CAD (Tianjin). The specimens, prepared from partially crystallized CAD/CAM blocks (3.0 mm), were fully crystallized and treated with 5% hydrofluoric acid for 20 s prior to SEM analysis. After acquiring the SEM images, ImageJ software was used to evaluate the average crystal length and crystalline content on the surface of the different ceramics. An inter-operator agreement was observed (ICC/p = 0.724), indicating that assessments by the various operators were similar across all ceramic materials tested (p < 0.001). When crystal length and crystalline content were compared, IRIS CAD exhibited significant differences compared to the other materials (p < 0.001), showing a less dense crystalline matrix based on the average length of crystals and the percentage of crystals per unit area. The use of this software facilitated the evaluation of crystalline content and average crystal lengths in dental ceramics using SEM images, and demonstrated very low variability among different operators. RESEARCH HIGHLIGHTS: The described method, using ImageJ open-source software, provides precise and reliable measurements of crystal length and crystalline content in lithium disilicate ceramics, with high inter-operator agreement. The proposed method identified higher crystalline content in IPS e.max CAD compared to Rosetta SM CAD and T-lithium CAD ceramics, while IRIS CAD exhibited significantly lower crystalline content and larger average crystal length. The novel, simplified method for assessing crystal length and crystalline content presented in this study may also be useful for evaluating other dental ceramics.
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http://dx.doi.org/10.1002/jemt.24700 | DOI Listing |
J Chem Phys
January 2025
Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA.
Phase change materials such as Ge2Sb2Te5 (GST) are ideal candidates for next-generation, non-volatile, solid-state memory due to the ability to retain binary data in the amorphous and crystal phases and rapidly transition between these phases to write/erase information. Thus, there is wide interest in using molecular modeling to study GST. Recently, a Gaussian Approximation Potential (GAP) was trained for GST to reproduce Density Functional Theory (DFT) energies and forces at a fraction of the computational cost [Zhou et al.
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO 80309, USA.
The current intense study of ferroelectric nematic liquid crystals was initiated by the observation of the same ferroelectric nematic phase in two independently discovered organic, rod-shaped, mesogenic compounds, RM734 and DIO. We recently reported that the compound RM734 also exhibits a monotropic, low-temperature, apolar phase having reentrant isotropic symmetry (the I phase), the formation of which is facilitated to a remarkable degree by doping with small (below 1%) amounts of the ionic liquid BMIM-PF. Here we report similar phenomenology in DIO, showing that this reentrant isotropic behavior is not only a property of RM734 but is rather a more general, material-independent feature of ferroelectric nematic mesogens.
View Article and Find Full Text PDFLangmuir
January 2025
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
Controllable preparation of inorganic nanomaterials with specific morphology and structure is very important for their applications in various fields. Herein, a general strategy was proposed to controllably synthesize nano-CaCO via a water-in-oil microemulsion method in the rotating packed bed reactor. By tuning key parameters, nano-CaCO with four primarily analyzed morphologies, including spherical, spindle-like, clustered, or linear formations, can be selectively obtained.
View Article and Find Full Text PDFNoncovalent carbon bonding (C-bonding), a recently explored σ-hole interaction, has primarily been characterized through X-ray structural and computational studies. Evidence of C-bonds in solution is scarce, especially in highly polar solvents like DMSO where solvation effects typically overshadow weak non-covalent interactions. In this work, we present three novel spiroisatin-based -acyl hydrazones (1-3) in which C-bonds play a critical role in stabilizing the conformation in solution.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
State Key Laboratory of Green Pesticide, Central China Normal University, Wuhan 430079, PR China. Electronic address:
The construction of helical structures through self-assembly and the exploration of their formation mechanisms not only amplify chiroptical properties but also provide profound insights into the structures and functions of natural helices. In this study, we developed a chiral Au(I) system based on BINAP and alkynyl ligands. The modification of the length or number of alkyl chains at the terminal positions of the alkynyl ligands significantly impacted the self-assembly behavior of the complexes.
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