PURPOSE The effect of dental fabrication procedures of zirconia monolithic restorations and changes in properties during low-temperature exposure in the oral environment is not completely understood. The purpose of this study was to investigate the effect of procedures for fabrication of dental restorations by low-temperature simulation and relative changes of flexural strength, nanoindentation...

In this study, we tailor the microstructure of hydroxyapatite/zirconia nanocrystalline composites by optimizing processing parameters, namely, introducing an atmosphere of water vapor during sintering in order to control the thermal stability of hydroxyapatite, and a modified sol-gel process that yields to an excellent intergranular distribution of zirconia phase dispersed intergranularly withi...

There is a continuous search for an alternative oxide material to the yttria-stabilized zirconia (7YSZ), which currently serves as the thermal barrier coating materials for turbine engines [1]. The new material should have low thermal conductivity, high temperature stability, and ferroelastic toughening as exhibited by the 7YSZ. Therefore in this study, the Y-Ta-Zr-O system was investigated. Th...

Introduction and Strategy Discovery of the extraordinary activity of sulfated zirconia for n-butane isomerization below 373K has led to numerous efforts to investigate and correlate structure, acidity, and reactivity of this material. Although a large data set has been obtained from powdered sulfated zirconia no consistent picture has evolved that satisfactorily describes acidity and reactivity...

Zirconia is a widely used oxide ceramic in various high performance applications due to its attractive mechanical, electrical and thermal properties. In particular, the material 3 mol% yttria stabilized tetragonal zirconia (3YTZ) has been shown to undergo superplastic deformation [1]. One crucial step in the understanding of processes like superplasticity involves the knowledge of appropriate c...

The calculations performed in this study indicate that efficient deposition of tetragonal yttria-stabilized zirconia ~YSZ! by chemical vapor deposition ~CVD! is feasible using metal chloride precursors ~Zr-Y-C-O-H-Cl system!. As reported in the literature, this work demonstrates that high oxygen content is necessary to efficiently utilize metal chloride precursors for depositing tetragonal YSZ ...

The tetragonal to monoclinic (t ! m) phase transformation during low temperature ( 100 8C) degradation (LTD) of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) sintered in air at different temperatures was investigated. It is found that the sintering temperature affected the density, crystalline phase and microstructure of the sintered body, as well as the LTD behavior. Also, the ons...

The nanocrystalline powders and polycrystalline materials on the basis of stabilized zirconia with tetragonal type of structure have been investigated. The forms of the normal vibrations of the tZrO2 have been built using the theory group methods. The peculiarities of experimentally obtained Raman spectra of studied materials have been explained with the help of analysis of symmetry and the for...

OBJECTIVES To evaluate the effect of Fe₂O₃on the optical properties of yttria-stabilised tetragonal zirconia (Y-TZP) dental ceramic when added, and to determine the correct content required to mimic the natural dentin. METHODS Disc-shaped Y-TZP specimens (0.50 ± 0.01 mm in thickness) containing various contents of Fe₂O₃were fabricated by cold isostatic pressing and pressureless sintering, and...

The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM techni...