TY - JOUR
T1 - Experimental and finite element study of residual thermal stresses in veneered Y-TZP structures
AU - Tanaka, Carina B.
AU - Harisha, Hossam
AU - Baldassarri, Marta
AU - Wolff, Mark S.
AU - Tong, Hui
AU - Meira, Josete B.C.
AU - Zhang, Yu
N1 - Funding Information:
Funding was provided by the United States National Institutes of Health, National Institute of Dental and Craniofacial Research (Grant 2R01 DE017925 ) and the National Science Foundation (Grant CMMI-0758530 ). The authors acknowledge the Brazilian agencies CAPES ( BEX 4909/13-5 ) and FAPESP ( 2012/17094-5 ; 2013/06988-8 ) for the financial support of the Ph.D student Carina B. Tanaka to conduct research at the New York University College of Dentistry as a visiting scholar.
Publisher Copyright:
© 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved
Includes bibliographical references
PY - 2016/5/15
Y1 - 2016/5/15
N2 - The main complications of zirconia-based laminated systems are chipping and delamination of veneering porcelain, which has been found to be directly associated with the development of residual thermal stresses in the porcelain layer. This study investigates the effects of cooling rate and specimen geometry on the residual stress states in porcelain-veneered zirconia structures. Bilayers of three different shapes (bars, semi-cylindrical shells, and arch-cubic structures) with 1.5 mm and 0.7 mm thickness of dentin porcelain and zirconia framework, respectively, were subjected to two cooling protocols: slow cooling (SC) at 32 °C/min and extremely-slow cooling (XSC) at 2 °C/min. The residual thermal stresses were determined using the Vickers indentation method and validated by finite element analysis. The residual stress profiles were similar among geometries in the same cooling protocol. XSC groups presented significantly higher tensile stresses (p=0.000), especially for curved interfaces. XSC is a time-consuming process that showed no beneficial effect regarding residual stresses compared to the manufacturer recommended slow cooling rate.
AB - The main complications of zirconia-based laminated systems are chipping and delamination of veneering porcelain, which has been found to be directly associated with the development of residual thermal stresses in the porcelain layer. This study investigates the effects of cooling rate and specimen geometry on the residual stress states in porcelain-veneered zirconia structures. Bilayers of three different shapes (bars, semi-cylindrical shells, and arch-cubic structures) with 1.5 mm and 0.7 mm thickness of dentin porcelain and zirconia framework, respectively, were subjected to two cooling protocols: slow cooling (SC) at 32 °C/min and extremely-slow cooling (XSC) at 2 °C/min. The residual thermal stresses were determined using the Vickers indentation method and validated by finite element analysis. The residual stress profiles were similar among geometries in the same cooling protocol. XSC groups presented significantly higher tensile stresses (p=0.000), especially for curved interfaces. XSC is a time-consuming process that showed no beneficial effect regarding residual stresses compared to the manufacturer recommended slow cooling rate.
KW - Cooling rates
KW - Finite element analysis
KW - Porcelain-veneered zirconia
KW - Residual thermal stresses
KW - Specimen geometries
KW - Vickers indentation method
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U2 - 10.1016/j.ceramint.2016.03.018
DO - 10.1016/j.ceramint.2016.03.018
M3 - Article
C2 - 27087734
AN - SCOPUS:84977904333
SN - 0272-8842
VL - 42
SP - 9214
EP - 9221
JO - Ceramics International
JF - Ceramics International
IS - 7
ER -