Fatigue susceptibility of an endodontic fibre post material , Abstract Aim Endodontically treated teeth are often restored using fibre posts. Fibre posts consist of glass fibres bound by resinous matrices. However, resins, fibres and their interfaces are known to undergo chemical, thermal, and mechanical fatigue. The purpose of this study was to evaluate effects of aging and fatigue on the elastic modulus and short-beam shear strength of a quartz fibre/epoxy resin post material. Methodology Cylindrical specimens (25mm x 2.2mm) were made. Elastic moduli were dynamically measured before immersion in water; after immersion in water; periodically during storage in water for up to 7 years; periodically during thermal cycling in water for up to 10,000 cycles to produce thermo-mechanical fatigue; and periodically during boiling in water for up to 100 hours. After aging, the specimens underwent short-beam shear strength testing. Results Elastic modulus was significantly decreased by thermal cycling and by immersion in boiling water, but not by water storage. Short beam shear strength was profoundly decreased by all three aging processes. Short beam shear strength was much more sensitive than elastic modulus to the aging or fatigue processes applied in this study. Conclusions A representative endodontic fibre-post material was susceptible to a variety of aging and fatigue processes. The effects of aging and fatigue had a more pronounced impact on short-beam shear strength than on elastic modulus. The effects of boiling in water and thermal cycling in water were considerably larger than those of simple storage in water. This article is protected by copyright. All rights reserved. , http://bit.ly/11Uypj2

Fatigue susceptibility of an endodontic fibre post material , Abstract Aim Endodontically treated teeth are often restored using fibre posts. Fibre posts consist of glass fibres bound by resinous matrices. However, resins, fibres and their interfaces are known to undergo chemical, thermal, and mechanical fatigue. The purpose of this study was to evaluate effects of aging and fatigue on the elastic modulus and short-beam shear strength of a quartz fibre/epoxy resin post material. Methodology Cylindrical specimens (25mm x 2.2mm) were made. Elastic moduli were dynamically measured before immersion in water; after immersion in water; periodically during storage in water for up to 7 years; periodically during thermal cycling in water for up to 10,000 cycles to produce thermo-mechanical fatigue; and periodically during boiling in water for up to 100 hours. After aging, the specimens underwent short-beam shear strength testing. Results Elastic modulus was significantly decreased by thermal cycling and by immersion in boiling water, but not by water storage. Short beam shear strength was profoundly decreased by all three aging processes. Short beam shear strength was much more sensitive than elastic modulus to the aging or fatigue processes applied in this study. Conclusions A representative endodontic fibre-post material was susceptible to a variety of aging and fatigue processes. The effects of aging and fatigue had a more pronounced impact on short-beam shear strength than on elastic modulus. The effects of boiling in water and thermal cycling in water were considerably larger than those of simple storage in water. This article is protected by copyright. All rights reserved. , http://bit.ly/11Uypj2 , via Dental Teach " Daily Dental Info " http://www.facebook.com/photo.php?fbid=587656027925617&set=a.582976205060266.1073741849.110664842291407&type=1