Abstract
Objectives. The aim of the current study was to assess the effect of core:dentin thickness ratio on the flexure strength, fracture mode and origin of bilayered dental ceramic composite disc specimens.
Methods. Sets of 30 bilayered composite discs with core:dentin thickness ratio of 2:1, 1:1 and 1:2 were tested in bi-axial flexure with both the reinforcing core and veneering dentin Loaded in tension. Mean flexure strengths, standard deviations and associated Weibull Moduli (m) were determined. A combination of optical and scanning electron microscopy was employed for identification of the fracture mode and origin.
Results. The core:dentin ratio influenced the bi-axial flexure strength and reliability of the flexure strength data when both the reinforcing core and veneering dentin porcelain were tested in tension. The strength and reliability was increased for a core:dentin thickness of 2:1. The number of fracture fragments, the frequency of occurrence of specimen delaminations, Hertzian cone formations and sub-critical radial cracking in the bilayered dental ceramic composite disc shaped specimens was also dependent on the core/dentin ratio and the surface loaded in tension.
Conclusions. Core:dentin thickness ratio influences the bi-axial flexure strength and fracture mode and origin in bilayered dental ceramic composite specimens. (C) 2004 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 164 - 171 |
Number of pages | 8 |
Journal | Dental Materials |
Volume | 21 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Feb 2005 |
Keywords
- bi-axial flexure strength
- delamination
- bilayering
- Weibull analysis