Local atomic structures of Zr and dopant cations in zirconia solid solutions with Fe,03, Ga203, Y203, and Gd203 .have been determined. The Zr ions in both partially stabilized tetragonal and fully stabilized cubic zirconia have their own characteristic structures which are dopant-independent. The dopant cations substitute for Zr ions despite severe local distortions necessitated by the large di...

Well-aligned, densely distributed ZrO2 nanorod arrays were fabricated using a non-catalytic, templatefree metal–organic chemical vapour deposition process at a reaction temperature of 1000 C. The reaction temperature was found to play a key role in product morphology, with particle thin films obtained at 550 C and nanorod arrays produced at 1000 C. Increasing the reaction temperature led to the...

As was shown in the past by XRD, TEM and RBS measurements, heavy ion irradiation of nanocrystalline ZrO2 samples using 4 MeV Kr + ions causes the formation of a tetragonal zirconia phase that is stable at room temperature [1]. This phase is employed in solid oxide fuel cells and oxygen sensors, but usually has to be stabilized by addition of a second phase, e.g. Y2O3, which is not necessary whe...

Nitration of toluene has been studied in the liquid phase over a series of modified zirconia catalysts. Zirconia, zirconiaceria (Zr0.98Ce0.02)O2, sulfated zirconia and sulfated zirconiaceria were synthesised by co precipitation method and were characterised by X-ray diffraction, BET surface area, Infra red spectroscopy analysis (FTIR), Thermogravimetric analysis (TGA), Scanning Electron Microsc...

Significant progress has been achieved in ceramics since the late 1990s1-4). In particular, new technological innovations such as heat-pressed5,6), injection-molded7), slip-cast8), and glass-infiltrated ceramics9-11) have widened the use of ceramics in prosthetic and operative dentistry. However, properties such as brittleness limit their use in applications such as fixed partial dentures. Sinc...

objectives: masking ability of a restorative material plays a role in hiding colored substructures; however, the masking ability of zirconia ceramic (zrc) has not yet been clearly understood in zirconia-based restorations. this study evaluated the effect of three different core materials on masking ability of a zrc. materials and methods: ten zirconia disc samples, 0.5mm in thickness and 10mm i...

objectives : studies on the effect of coloring procedures on the bond strength of zirconia to resin cement are lacking in the literature. this study evaluated the effect of dipping of zirconia ceramic in different liquid color shades on the microtensile bond strength (mtbs) of zirconia ceramic to resin cement. materials and methods: this in vitro study was conducted on 100 microbar specimens di...

During the past decade, zirconia-based ceramics have been successfully introduced into the clinic to fabricate fixed dental prostheses (FDPs), along with a dental computer-aided/computer-aided manufacturing (CAD/CAM) system. In this article (1) development of dental ceramics, (2) the current status of dental CAD/CAM systems, (3) CAD/CAM and zirconia restoration, (4) bond between zirconia and ve...

OBJECTIVES To evaluate the bonding of resin-cement to yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) via silica coating followed by silanization, and three one-bottle universal adhesives, with or without prior conditioning using a zirconia primer. METHODS Y-TZP specimens (n=160) were conditioned by tribochemical silica coating and silanization (CS), or alumina sandblasting with one...

Tetragonal Zirconia Polycrystals stabilized with 3% mol. content of yttria (3Y-TZP) has excellent properties in terms of strength and fracture toughness. These properties are mostly imputable to the transformation toughening mechanism, by which the doped metastable tetragonal phase of zirconia transforms to monoclinic under applied stress ahead of a crack. This phenomenon is accompanied by a vo...