Effect of thickness of zirconia-ceramic crown frameworks on strength and fracture pattern.
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.
Fixed Prosthodontics, Department of Restorative Sciences, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Satoshi
S
Omori
Wataru
W
Komada
Keiichi
K
Yoshida
Hiroyuki
H
Miura
D000537:Aluminum Oxide / Q000737:chemistry*; D000704:Analysis of Variance; D002516:Ceramics / Q000737:chemistry*; D002563:Cerium / Q000737:chemistry*; D002857:Chromium; D003035:Cobalt; D003442:Crowns; D003722:Dental Alloys / Q000737:chemistry; D017267:Dental Prosthesis Design / Q000379:methods*; D003799:Dental Stress Analysis; D019544:Equipment Failure Analysis; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
C475766:Ce-TZP-Al2O3; D003722:Dental Alloys; C499362:yttria stabilized tetragonal zirconia; D002857:Chromium; D002563:Cerium; D003035:Cobalt; D015019:Yttrium; D015040:Zirconium; D000537:Aluminum Oxide