Unstable cracking (chipping) of veneering porcelain on all-ceramic dental crowns and fixed partial dentures
✍ Scribed by M.V. Swain
- Book ID
- 103999574
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 684 KB
- Volume
- 5
- Category
- Article
- ISSN
- 1742-7061
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✦ Synopsis
The central argument of this study is that residual stresses developed during the preparation of all-ceramic crowns and fixed partial dentures coupled with contact-induced cracking are the origin of the excessive chipping observed in clinical applications. The aim of this paper is to provide a simple basic analysis of the causes of residual stress development in ceramics and identify the key thermo-mechanical parameters responsible for these stresses and the resultant contact-induced failure. For simplicity, a bilayer planar geometry is considered. The key outcomes are the critical role of thermo-elastic properties and the thickness of the structures. The approach is then used to evaluate the propensity for unstable cracking of a range of crown structures, including substructures of a range of ceramics, and to show that two specific combinations are most prone to this behaviour, namely porcelain fused to glass ceramics and zirconia substrates. In addition, a simple approach for the minimization of the likelihood for such behaviour and chipping is proposed.