Effect of thickness of zirconia-ceramic crown frameworks on strength and fracture pattern

Dent Mater J. 2013;32(1):189-94. doi: 10.4012/dmj.2012-255.

Abstract

The aim of the present study was to evaluate the fracture load and fracture mode of thin Ceria-stabilized tetragonal zirconia polycrystals/Al(2)O(3 )nanocomposites (Ce-TZP/A) and Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) crown frameworks. Artificial maxillary second premolars were prepared for metal-ceramic crown and all-ceramic crown restorations and Co-Cr tooth analogs were duplicated. 10 standard (0.5 mm overall thickness) zirconia-ceramic crown frameworks (Y-TZPs) for all-ceramic crown preparation and 10 modified (a 0.3-mm-thick framework increased in thickness by adding a 1.0-mm-thick palatal margin with a height of 2.0 mm) zirconia-ceramic crown frameworks (Y-TZPm, Ce-TZP/Am) for metal-ceramic crown preparation were fabricated. The frameworks were cemented to the Co-Cr tooth analog and loaded vertically until fracture. The fracture load of Y-TZPs (180.0 N) and Ce-TZP/Am (183.7 N) were significantly higher than that of Y-TZPm (133.7 N). There was a significant difference in fracture mode between Y-TZPm and Ce-TZP/Am. Within the limitation of this study, Ce-TZP/Am provide sufficient strength for clinical application.

MeSH terms

  • Aluminum Oxide / chemistry*
  • Analysis of Variance
  • Ceramics / chemistry*
  • Cerium / chemistry*
  • Chromium
  • Cobalt
  • Crowns*
  • Dental Alloys / chemistry
  • Dental Prosthesis Design / methods*
  • Dental Stress Analysis
  • Equipment Failure Analysis
  • Materials Testing
  • Nanocomposites / chemistry*
  • Yttrium / chemistry*
  • Zirconium / chemistry*

Substances

  • Ce-TZP-Al2O3
  • Dental Alloys
  • yttria stabilized tetragonal zirconia
  • Chromium
  • Cerium
  • Cobalt
  • Yttrium
  • Zirconium
  • Aluminum Oxide