Making yttria-stabilized tetragonal zirconia translucent

Research output: Contribution to journalArticle

Abstract

Objective. The aim of this study was to provide a design guideline for developing tetragonal yttria-stabilized zirconia with improved translucency. Methods. The translucency, the in-line transmission in particular, of 3 mol.% yttria-stabilized tetragonal zirconia (3Y-TZP) has been examined using the Rayleigh scattering model. The theory predicts that the in-line transmission of 3Y-TZP can be related to its thickness with grain size and birefringence the governing parameters. To achieve a threshold value of translucency, the critical grain size of 3Y-TZP was predicted for various thicknesses (0.3-2.0 mm). The threshold value was defined by a measured average in-line transmission value of a suite of dental porcelains with a common thickness of 1 mm. Our theoretical predictions were calibrated with one of the very few experimental data available in the literature. Results. For a dense, high-purity zirconia, its in-line transmission increased with decreasing grain size and thickness. To achieve a translucency similar to that of dental porcelains, a nanocyrstalline 3Y-TZP structure was necessitated, due primarily to its large birefringenceand high refractive index. Such a grain size dependence became more pronounced as the 3Y-TZP thickness increased. For example, at a thickness of 1.3 mm, the mean grain size of a translucent 3Y-TZP should be 82 nm. At 1.5 mm and 2 mm thicknesses, the mean grain size needed to be 77 nm and 70 nm, respectively. Significance. A promising future for zirconia restorations, with combined translucency and mechanical properties, can be realized by reducing its grain size.

Original languageEnglish (US)
Pages (from-to)1195-1203
Number of pages9
JournalDental Materials
Volume30
Issue number10
DOIs
StatePublished - Jan 1 2014

    Fingerprint

Keywords

  • Grain size
  • Light scattering
  • Microstructure
  • Optical birefringence
  • Translucency
  • Zirconia (Y-TZP)

ASJC Scopus subject areas

  • Materials Science(all)
  • Dentistry(all)
  • Mechanics of Materials

Cite this