PURPOSE Different types of tooth preparations influence the marginal precision of zirconium-oxide based ceramic single crowns. In this in vivo study, the marginal fits of zirconium-oxide based ceramic single crowns with vertical and horizontal finish lines were compared. MATERIALS AND METHODS Forty-six teeth were chosen in eight patients indicated for extraction for implant placement. CAD/CAM...

The electronic spectrum of a cold molecular beam of zirconium dioxide, ZrO(2), has been investigated using laser induced fluorescence (LIF) in the region from 17,000 cm(-1) to 18,800 cm(-1) and by mass-resolved resonance enhanced multi-photon ionization (REMPI) spectroscopy from 17,000 cm(-1)-21,000 cm(-1). The LIF and REMPI spectra are assigned to progressions in the Ã(1)B(2)(ν(1), ν(2), ν(3))...

The dispersion of small amounts of Ce(4+) ions in the bulk of ZrO2 leads to a photoactive material sensitive to visible light. This is shown by monitoring with EPR the formation and the reactivity of photogenerated (λ > 420 nm) charge carriers. The effect, as confirmed by DFT calculations, is due to the presence in the solid of empty 4f Ce states at the mid gap, which act as intermediate levels...

M. Amiriyan, S. Ramesh*, R. Tolouei, W.J. Kelvin Chew, J. Purbolaksono, M.A. Hassan, M. Hamdi and W.D. Teng Faculty of Science and Engineering, Laval University, Quebec, G1V 0A6 Canada Centre of Advanced Manufacturing & Material Processing (AMMP), Department of Engineering Design and Manufacture, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia Ceramics Technology Grou...

Biological synthesis of nanoparticles (NPs) has gained extensive attention during recent years by using various biological resources such as plant extracts and microorganisms as reducing and stabilizing agents. The objective of the present study was to biosynthesize zirconium NPs using Penicillium species as a reliable and eco-friendly protocol for the first time. The synthesized NPs w...

In this study, isophthalic acid-zirconium(IV) nanocomposite has been prepared from zirconyl nitrate pentahydrate and potassium iodide, with isophthalic acid, (C8H6O4=Benzene-1,3-dicarboxylic acid) as a ligand, via sonochemical method in ethylene glycol and methanol as solvents. The crystalline tetragonal ZrO2 has been produced by thermal decomposition of isophthalic acid-zirconium(IV) nanocompo...

A new catalytic kinetic spectrophotometric procedure for determination of trace quantities of zirconium was proposed. Janus Green was oxidized by potassium bromate and zirconium catalyst which then converted to a colorless product in acidic media. Reaction rate was monitored spectrophotometrically at 606 nm. It relies on the linear relationship between the absorbance difference (ΔAt) and Zr(IV)...

The effect of zirconium (Zr) on the humoral immune response was studied by measuring the level of IgM-plaque forming cells (IgM-PFC) against sheep red blood cells (SRBC) in the spleen of C57 BL mice intraperitoneally injected with zirconium oxychloride. Two experiments, a single injection of zirconium oxychloride of 1/5, 1/10, 1/50, and 1/100 of the LD50 for intraperitoneal injection and contin...

zirconium dioxide, commonly known as zirconia, is an interesting material and is receiving growing attention due to its excellent mechanical properties. the solid was characterized for surface area measurements, scanningelectron microscopy (sem), energy dispersive x-ray diffractometry (edx) and potentiometric titrations. surface titrations were carried out at the temperature range 303 to 323k i...