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The influence of grain size on low‐temperature degradation of dental zirconia
Author(s) -
Hallmann Lubica,
Mehl Albert,
Ulmer Peter,
Reusser Eric,
Stadler Johannes,
Zenobi Renato,
Stawarczyk Bogna,
Özcan Mutlu,
Hämmerle Christoph H. F.
Publication year - 2012
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.31969
Subject(s) - materials science , x ray photoelectron spectroscopy , crystallite , raman spectroscopy , cubic zirconia , yttria stabilized zirconia , scanning electron microscope , grain size , sintering , phase (matter) , analytical chemistry (journal) , ceramic , tetragonal crystal system , composite material , chemical engineering , metallurgy , chemistry , physics , optics , organic chemistry , chromatography , engineering
The purpose of this study was to evaluate the influence of grain size and air abrasion on low‐temperature degradation (LTD) of yttria stabilized tetragonal zirconia polycrystalline (Y‐TZP). Disc‐shaped specimens were sintered at 1350, 1450, and 1600°C. Air abrasion was performed with different abrasive particles. The specimens were stored for 2 h at 134°C under 2.3 bar water vapor pressure. All specimens were characterized by X‐ray powder diffraction analysis (XRD), Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and field emission scanning electron microscopy (FESEM). Y‐TZP sintered at a temperature of 1350°C did not undergo the t–m phase transformation during accelerated aging. The diffusion‐controlled t–m phase transformation initiated with the specimens sintered at 1450°C. This transformation was remarkable for the specimens sintered at 1600°C. X‐ray photoelectron spectroscopy (XPS) measurements did not confirm the generation of Zr‐OH and Y‐OH bonds. No increase of yttrium concentration on the grain boundaries of Y‐TZP was detected, which could be responsible for the destabilization of dental zirconia ceramics. A slight increase of diffusion‐controlled t–m phase transformations was observed for all abraded specimens sintered at 1350 and 1450°C. The size of abrasive particles did not play a crucial role on LTD of Y‐TZP. The retardation of diffusion‐controlled t–m phase transformation was evident for all abraded specimens sintered at 1600°C by comparison to non‐abraded specimens. Conclusion: The LTD of Y‐TZP can be suppressed when the sintering temperature is set between 1350 and 1450°C. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 447–456, 2012.