Margin failures in crown-like brittle structures: Off-axis loading

The effect of off-axis loading of compliant indenters on the initiation of cracks at the margins of dental crown-like dome structures consisting of glass shells back-filled with an epoxy resin is examined. As in previous studies on similar structures but with strictly axial loading, cracks can be ma...

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Main Authors: Ford, Christopher, Qasim, T., Bush, M., Hu, X., Shah, M., Saxena, V., Lawn, B.
Format: Journal Article
Published: John Wiley & Sons, Inc. 2008
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/18508
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author Ford, Christopher
Qasim, T.
Bush, M.
Hu, X.
Shah, M.
Saxena, V.
Lawn, B.
author_facet Ford, Christopher
Qasim, T.
Bush, M.
Hu, X.
Shah, M.
Saxena, V.
Lawn, B.
author_sort Ford, Christopher
building Curtin Institutional Repository
collection Online Access
description The effect of off-axis loading of compliant indenters on the initiation of cracks at the margins of dental crown-like dome structures consisting of glass shells back-filled with an epoxy resin is examined. As in previous studies on similar structures but with strictly axial loading, cracks can be made to initiate and propagate from the margins around the dome faces into a "semi-lunar" fracture pattern characteristic of some all-ceramic crown failures. In this study, balsa wood and teflon disk indenters are used to provide the off-axis loading, at 45° to the dome axis. The soft indenters, considered representative of food bolus, spread the contact at the top surface, suppressing otherwise dominant radial cracks that ordinarily initiate at the dome undersurface directly along the load axis beneath harder indenters. Finite element modeling is used to show that off-axis loading dramatically increases the tensile stresses at the near-side dome margin, strongly diminishing the loads required to generate the lunar fracture mode.
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institution Curtin University Malaysia
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publishDate 2008
publisher John Wiley & Sons, Inc.
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spelling curtin-20.500.11937-185082017-09-13T13:43:51Z Margin failures in crown-like brittle structures: Off-axis loading Ford, Christopher Qasim, T. Bush, M. Hu, X. Shah, M. Saxena, V. Lawn, B. Stress analysis Lunar cracks All-ceramic crowns Soft indenters Crown failure The effect of off-axis loading of compliant indenters on the initiation of cracks at the margins of dental crown-like dome structures consisting of glass shells back-filled with an epoxy resin is examined. As in previous studies on similar structures but with strictly axial loading, cracks can be made to initiate and propagate from the margins around the dome faces into a "semi-lunar" fracture pattern characteristic of some all-ceramic crown failures. In this study, balsa wood and teflon disk indenters are used to provide the off-axis loading, at 45° to the dome axis. The soft indenters, considered representative of food bolus, spread the contact at the top surface, suppressing otherwise dominant radial cracks that ordinarily initiate at the dome undersurface directly along the load axis beneath harder indenters. Finite element modeling is used to show that off-axis loading dramatically increases the tensile stresses at the near-side dome margin, strongly diminishing the loads required to generate the lunar fracture mode. 2008 Journal Article http://hdl.handle.net/20.500.11937/18508 10.1002/jbm.b.30911 John Wiley & Sons, Inc. restricted
spellingShingle Stress analysis
Lunar cracks
All-ceramic crowns
Soft indenters
Crown failure
Ford, Christopher
Qasim, T.
Bush, M.
Hu, X.
Shah, M.
Saxena, V.
Lawn, B.
Margin failures in crown-like brittle structures: Off-axis loading
title Margin failures in crown-like brittle structures: Off-axis loading
title_full Margin failures in crown-like brittle structures: Off-axis loading
title_fullStr Margin failures in crown-like brittle structures: Off-axis loading
title_full_unstemmed Margin failures in crown-like brittle structures: Off-axis loading
title_short Margin failures in crown-like brittle structures: Off-axis loading
title_sort margin failures in crown-like brittle structures: off-axis loading
topic Stress analysis
Lunar cracks
All-ceramic crowns
Soft indenters
Crown failure
url http://hdl.handle.net/20.500.11937/18508