Fracture Resistance of Customized Fiber Posts versus Custom Made PEEK Posts with Two Fabrication Techniques (Finite element analysis and an in vitro study)

Abstract

When taking into account the restoration of devitalized teeth, dental materials have to be able to restore this structure loss, in order to guarantee mechanical and functional properties, esthetics and preservation of coronal seal. (15) A post-and-core might be essential to promote retention and resistance form for the tooth-restoration unit, when a full crown is the line of treatment needed to restore an endodontically treated tooth. (25) The material of post-and-core should have mechanical and physical properties close to those of dentin so as to better tolerate the occlusal loads, preventing tooth fracture or de-bonding of the post. (25) The emergence of new post material with a lower elastic modulus, fiber glass for example, resulted in more favourable stress distribution. However, as fiber glass posts are supplied as ready-made products, they have limited conformity to the figures of the root canal. In addition, although fiber glass posts have reduced moduli of elasticity (from45.7 to 53.8GPa) than those of different metal alloy posts (110.0GPa for titanium and 95.0GPa for gold), these are still nearly three times the elastic modulus of dentin (18.6GPa). (1) A new biocompatible high performance polymers, PolyEtherKetoneKetones (PEKKs), were introduced as a new dental materials. Because of their acceptable fracture resistance, better shock-absorbing ability and stress distribution, high performance polymers are considered as alternative novel materials for metal and glass ceramics (3). Unfortunately, studying biomechanical behavior and performing multi-parameter analysis on different types of post-core systems is difficult, time consuming and uneconomic. Finite element analysis is a numerical method to investigate the stress and strain exerted on relevant structures, and in turn predict where a fracture might occur. (7)