Evidence of yttrium silicate inclusions in YSZ-porcelain veneers.

Published

Journal Article

This report introduces the discovery of crystalline defects that can form in the porcelain veneering layer when in contact with yttria-stabilized zirconia (YSZ). The focus was on dental prostheses and understanding the defects that form in the YSZ/porcelain system; however the data reported herein may have broader implications toward the use and stability of YSZ-based ceramics in general. Specimens were cut from fully sintered YSZ plates and veneering porcelain was applied (<1 mm thick) to one surface and fired under manufacturer's recommended protocol. Scanning electron microscopy (SEM) with integrated electron dispersive X-ray (EDAX) was used for microstructural and elemental analysis. EDAX, for chemical analysis and transmission electron diffraction (TED) for structural analysis were both performed in the transmission electron microscope (TEM). Additionally, in order to spatially resolve Y-rich precipitates, micro-CT scans were conducted at varying depths within the porcelain veneer. Local EDAX (SEM) was performed in the regions of visible inclusions and showed significant increases in yttrium concentration. TEM specimens also showed apparent inclusions in the porcelain and selected area electron diffraction was performed on these regions and found the inclusions to be crystalline and identified as either yttrium-silicate (Y2 SiO5 ) or yttrium-disilicate (Y2 Si2 O7 ). Micro-CT data showed that yttrium-silicate precipitates were distributed throughout the thickness of the porcelain veneer. Future studies are needed to determine whether many of the premature failures associated with this materials system may be the result of crystalline flaws that form as a result of high temperature yttrium diffusion near the surfaces of YSZ.

Full Text

Duke Authors

Cited Authors

  • Stoner, BR; Griggs, JA; Neidigh, J; Piascik, JR

Published Date

  • April 2014

Published In

Volume / Issue

  • 102 / 3

Start / End Page

  • 441 - 446

PubMed ID

  • 24106151

Pubmed Central ID

  • 24106151

Electronic International Standard Serial Number (EISSN)

  • 1552-4981

International Standard Serial Number (ISSN)

  • 1552-4973

Digital Object Identifier (DOI)

  • 10.1002/jbm.b.33021

Language

  • eng