Higher yttria content enhances the translucency and appearance of dental zirconia materials. Alterations in material composition also affect mechanical properties. The aim of this study was to compare the fracture load after artificial short-term aging of monolithic, full-contour zirconia crowns with different amounts of yttria-stabilization. Sixty crowns (thirty super high translucent crowns (5Y-Z) and thirty high translucent crowns (3Y-Z)) were produced to fit a model of a premolar with a shallow chamfer preparation. The crowns were cemented with self-adhesive resin cement on composite abutments. For each zirconia type, three groups of crowns (n = 10) were allocated to: (i) cyclic loading (200 N, 1 Hz, 30,000 cycles), (ii) hydrothermal aging (3 × 20 min, 134°C 3.2 bar), or (iii) no treatment (control). Surviving crowns from the aging process were quasistatically loaded until fracture. The 3Y-Z crowns had statistically significantly higher fracture values (3,449 N) than the 5Y-Z crowns (1,938 N). The aging procedures did not affect load at fracture. Fractographic analysis showed that fractures started either at the crown margin or at the occlusal intaglio area. Higher yttria content leads to a reduction in material strength and damage tolerance, and this should be reflected in recommendations for clinical use.
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http://dx.doi.org/10.1111/eos.12739 | DOI Listing |
J Oral Biol Craniofac Res
December 2024
Department of Oral Biology and Oral Pathology, Saveetha Dental College and Hopsitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, 600077, India.
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View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics, Research Centre of Excellence for Organic Electronics and Institute of Advanced Materials, Hong Kong Baptist University, Hong Kong, China.
The artistic and scientific perspectives of the translucent color organic solar cells (OSCs), made with the emerging narrowband nonfullerene acceptors are explored. The translucent color OSCs, comprising a Fabry-Pérot microcavity optical coupling layer, have a power conversion efficiency of >15% and a maximum transparency of >20% for the three primary colors. The performance-color relationship of the translucent color OSCs is analyzed using a combination of high-throughput optical computing and experimental optimization, allowing light with desired color to pass through, while absorbing enough light to generate electricity.
View Article and Find Full Text PDFJ Morphol
January 2025
Department of Biology, Gonzaga University, Spokane, Washington, USA.
For over a century researchers have marveled at the square-shaped toe tips of several species of climbing salamanders (genus Aneides), speculating about the function of large blood sinuses therein. Wandering salamanders (Aneides vagrans) have been reported to exhibit exquisite locomotor control while climbing, jumping, and gliding high (88 m) within the redwood canopy; however, a detailed investigation of their digital vascular system has yet to be conducted. Here, we describe the vascular and osteological structure of, and blood circulation through, the distal regions of the toes of A.
View Article and Find Full Text PDFMorphologie
January 2025
Department of Biostatistics, KS Hegde Medical Academy, Nitte (deemed to be university), Mangalore, Karnataka, India.
Introduction: In the forensic field, having accurate understanding of the macroscopic and microscopic alterations that occur in teeth when exposed to temperatures has remarkable significance. The preservation of delicate incinerated teeth is crucial in fire investigations that pertain to the temperature exposed, as well as the identification of victims. This preservation is necessary in order to conduct macroscopic and microscopic ultra-structural examinations, which provide valuable insights into the structural alterations that dental tissues undergo when exposed to low to high temperatures.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Periodontics Dentistry and Community Dentistry, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
(1) Background: Alkasite is a novel restorative material that has attracted interest in recent years because of its distinctive characteristics, including its high translucency and excellent biocompatibility. It is comparable to glass ionomer cement (GIC) and resin-modified glass ionomer cement (RMGIC) due to its fluoride-release ability and usage in esthetically concerned areas. This study aimed to assess the shear bond strength (SBS) of Alkasite restorative material in comparison with GIC and RMGIC (2) Methods: The study sample included 120 extracted sound primary molars and was randomly split into three groups, including group 1: RMGIC; group 2: Alkasite; and group 3: GIC.
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