PURPOSE This study aimed to evaluate the fit of zirconia ceramics before and after veneering, using 3 different veneering processes (layering, press-over, and CAD-on techniques). MATERIALS AND METHODS Thirty standardized zirconia CAD/CAM frameworks were constructed and divided into three groups of 10 each. The first group was veneered using the traditional layering technique. Press-over and C...

Objectives: To test the wear of enamel against Yttria Tetragonal Zirconia Polycrystals (Y-TZP) in comparison to the wear of enamel against a noble white high Palladium alloy. Methods: A total of 20 specimens were used, 10 of Y-TZP and 10 of High Palladium alloy, both were subjected to 202,800 contacts against an enamel rod 2x2 mm in cross section under a mean load of 475.04g leading to a mean f...

The aim of this study was the electrospinning zirconia nanofibers without sol-gel precursors. Low-cost Zr-oxide and Zr-carbonate inorganic materials, with high molecular Zr-content compared to methods, were used for precursor formulation. Using a polyvinylpyrrolidone (PVP) polymeric binder, could successfully be synthesised both Zr-sources. effects different parameters investigated stabilize pr...

In recent years, 3 mol% yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) doped with copper oxide has obtained increasing interest due to its enhanced superplasticity and good potential in tribological applications. In this work, the effect of addition of small amounts (0.8 mol%) of CuO on the sintering behaviour of 3Y-TZP was studied using a dilatometer and high temperature X-ray dif...

Combinations of three simple techniques were utilized to gradually form zirconia nanoneedles from zirconium nanograins. First, a physical vapor deposition magnetron sputtering technique was used to deposit pure zirconium nanograins on top of a substrate. Second, an anodic oxidation was applied to fabricate zirconia nanotubular arrays. Finally, heat treatment was used at different annealing temp...

Due to their aesthetic value and high compressive strength, dentists have recently employed ceramics for restoration materials. Among the ceramic materials, zirconia provides high toughness and crack resistant characteristics. Residual stresses develop in processing due to factors including grain anisotropy and thermal coefficient mismatch. In the present study, polychromatic X-ray (Laue) micro...

STATEMENT OF PROBLEM Porcelain fused to zirconia prostheses are widely used. However, porcelain chipping, spalling, fracture, and delamination are common clinical problems. Residual stresses of thermal origin have received attention, but clear data and firing guidelines remain absent. PURPOSE The purpose of this study was to measure the influence of heating and cooling protocols on the streng...

Thermal barrier coatings (TBC) are used widely on a range of components that operate at high temperatures. We report measurement of the factor that is required to convert the Raman shift to stress for air plasma sprayed yttria (7 wt %) stabilized tetragonal zirconia (ZrO(2)) (YSZ) thermal barrier coatings. The factor is evaluated for the as-coated condition and also following a heat treatment a...

Abstract In this investigation, surface modification toughening of partially stabilized zirconia ceramics, by sub-eutectoid solution annealing, has been performed. The Zr 0.918 Mg 0.068 Y 0.014 O 1.925 designated (MZY) was prepared mixing Magnesia Partially Stabilized Zirconia (MZ9) and Yttria Tetragonal (TZ3Y) Polycrystal commercial powders using wet ball milling. mechanical properties microst...