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...

background. the color masking ability of a restoration plays a significant role in coveringa discolored substructure; how-ever, this optical property of zirconia ceramics has not been clearly determined yet. the aim of this in vitro study was to evaluate the color masking ability of a zirconia ceramic on substrates with different values. methods. ten zirconia disk specimens,0.5 mm in thickness ...

The purpose of this study was to investigate and analyse the fracture toughness of yttria stabilized tetragonal zirconia polycrystal (Y-TZP) dental ceramics by means of the Vickers indentation technique. Fracture toughness was analysed under the following loads: 29.42 N, 49.03 N, 196.13 N, and 294.20 N. Cracks that had developed from the vertices of a Vickers indentation were measured and used ...

This study evaluated microstructural and crystallographic phase changes after grinding (G) and regeneration firing/anneling (R) of Y-TZP ceramics. Thirty five bars (LavaTM and Ice Zirkon) were divided: Y-TZP pre-sintered, control (C), regeneration firing (R), dry grinding (DG), dry grinding+regeneration firing (DGR), wet grinding (WG) and wet grinding+regeneration firing (WGR). Grinding was con...

OBJECTIVES (1) To synthesize 3mol% yttria-stabilized zirconia (3Y-TZP) powders via coprecipitation route, (2) to obtain zirconia ceramic specimens, analyze surface characteristics, and mechanical properties, and (3) to compare the processed material with three reinforced dental ceramics. METHODS A coprecipitation route was used to synthesize a 3mol% yttria-stabilized zirconia ceramic processe...

The purpose of this in vitro study was to compare the effect staining, glazing, and polishing on wear behavior stabilized zirconia with 5 mol% yttrium oxide (5Y-TZP) opposing 5Y-TZP, leucite-reinforced ceramic (LC), lithium disilicate (LD), microhybrid composite resin (MCR). Hemispheres 5Y-TZP were divided into six groups (n = 10) according finishing procedure: C (control), S (staining), G (gla...

Subsurface hydrothermal degradation of yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) is presented. Evaluation of low temperature degradation (LTD) phase transformation induced by aging in 3Y-TZP is experimentally studied by Raman confocal microspectroscopy. A non-linear distribution of monoclinic volume fraction is determined in depth by using different pinhole sizes. A theoretica...

Zirconia ceramics have several advantages over other ceramic materials, due to the transformation toughening mechanisms operating in their microstructure that can give to components made out of them, very interesting mechanical properties. The research on the use of zirconia ceramics as biomaterials started about twenty years ago, and now zirconia (Y-YZP) is in clinical use in THR, but developm...