Effect of coloring with various metal oxides on the microstructure, color, and flexural strength of 3Y‐TZP

Abstract

The purpose of this study was to investigate the effect of cerium and bismuth coloring salts solutions on the microstructure, color, flexural strength, and aging resistance of tetragonal zirconia for dental applications (3Y-TZP). Cylindrical blanks were sectioned into disks (2-mm thick, 25-mm in diameter) and colored by immersion in cerium acetate (CA), cerium chloride (CC), or bismuth chloride (BC) solutions at 1, 5, or 10 wt %. The density, elastic constants, and biaxial flexural strength were determined after sintering at 1350 degrees C. The crystalline phases were analyzed by X-ray diffraction before and after aging in autoclave for 10 h. The results showed that the mean density of the colored groups was comparable with that of the control group (6.072 +/- 0.008 g/cm(3)). XRD confirmed the presence of tetragonal zirconia with a slight increase in lattice parameters for the colored groups. A perceptible color difference was obtained for all groups (DeltaE* = 2.57 +/- 0.48 to 14.22 +/- 0.98), compared with the control. The mean grain size increased significantly for the groups colored with CC or CA at 10 wt %, compared with the control group (0.318 +/- 0.029 mm). The mean biaxial strength of CA1%, CA5%, and BC1% groups was not significantly different from that of the control group (1087.5 +/- 173.3 MPa). The flexural strength of all other groups decreased linearly with increasing concentration for both cerium salts (860.7 +/- 172 to 274.4 +/- 67.3 MPa). The resistance to low temperature degradation was not affected by the coloring process. Coloring with cerium or bismuth salts produced perceptible color differences even at the lowest concentrations. A decrease in flexural strength at the higher concentrations was attributed to an increase in open porosity.

Enhanced reliability of yttria-stabilized zirconia for dental applications

“…Infiltration with Ce acetate was adopted for coloring purposes, observing no change in mechanical properties up to concentration of 5 wt% in water solutions [7]. Ce nitrate has been used for powder coating since this highly soluble salt distributes evenly once the solvent is evaporated, obtaining CeO 2 after calcination [27].…”

Relative Translucency of a Multilayered Ultratranslucent Zirconia Material

“…1,2 The base material is white and can be shaded by adding colorants of different types and concentrations. [3][4][5] The major drawback of zirconia is its relative opaque appearance when compared with glass ceramics. 6 This poor optical property can be addressed by veneering the opaque core with porcelain or making full contour monolithic restorations with more translucent ZrO 2 materials.…”

“…According to the type of restoration, UTML is designed to have minimal thicknesses: 0. 4 The objectives of the present study are to assess the TP of the UTML according to thickness and layer level. The hypotheses tested in the study were that: (1) the layers in UTML have different TP values at similar thicknesses and (2) TP of the UTML material is affected by thickness.…”

Zirconia ceramics in metal-free implant dentistry

“…The pigments may segregate inside the grain boundaries or deposit on the outer surface of the products, yielding elongated grain structures, surface lifts, and numerous small pores [88]. These changes are detrimental to the strength, and can occur especially when the concentration of the dipping solution is high [89][90][91] or the shading time is prolonged [91]. An alternative colouring method is to dope zirconia powders or blocks directly with metal oxides.…”