Characterization of magnesia-doped yttria-stabilized zirconia powders for dental technology applications
Damian Nakonieczny1, Witold Walke1, Justyna Majewska2
1Department of Biomaterials and Medical Devices Engineering, Faculty of Biomedical Engineering, Silesian University of Technology, Zabrze, Poland.
Purpose:
This paper is focused on the works concerning preparation of zirconium oxide ceramic blocks recommended for CAD/CAM systems used in prosthetic dentistry for manufacturing fixed prosthetic restorations.
Methods:
Zirconium-yttrium-magnesium mixed ceramic oxides were prepared by sol-gel method via hydrolysis and condensation of zirconium alkoxide precursor (zirconium (IV) propoxide) with yttrium and magnesium nitrates diluted in 2-propanol. The aim of this work was to obtain 2% mol yttria-stabilized zirconia ceramic powders with magnesium as an additional tetragonal ZrO2 phase stabilizer in amount between 2÷6% mol (with 2% variable). Prepared gels were dried (24 h at 65 °C). Obtained powders were mixed with binder (carboxymethyl cellulose) and uniaxial pressed into specimens with a dimensions 38 × 22 × 6 mm. Afterwards green bodies were sintered in range of temperature between 1350-1550 °C. Powders and blocks were characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, Specific Area Measurement.
Results:
Highly homogeneous powders with a low open porosity were obtained. Prepared blocks after sintering showed numerous cracks. Nevertheless blocks were fine grained and showed quite reproducible chemical composition.
Conclusion:
A sol gel wet chemical route of powder synthesis allow us to obtain high homogenous ceramic materials with inconsiderable amount of pores with low variation in dimensions. In spite of a reproducible synthesis methods of a ceramic powders, applied to prepare green bodies procedure and sintering manner do not allowed to obtain zirconia cermic blocks free from cracks.
