Can Fiber Posts Increase Root Stresses and Reduce Fracture?

Abstract

The clinical success of fiber posts has been attributed to their lower elastic modulus. The tested hypothesis was that fiber posts could lead to lower risk of post debonding and lower risk of root fracture, despite an increase in root stresses. Stress analyses were carried out with a 3D finite element model of a premolar restored with a metallic or a fiber post. Bonded and non-bonded post/cement interface conditions were simulated. We calculated risk-of-fracture indices by determining the highest principal stress values divided by the tensile strength. Shear stresses along the post/cement interface were analyzed for the bonded models. Compared with the premolar restored with a metallic post, the fiber post generated lower stresses along the interface and higher stresses in the root. However, with the fiber post, fracture was less likely to occur in the root, since its core and post fracture indices were higher.

Effects of threaded post placement on strain and stress distribution of endodontically treated teeth

“…22 The post material should have an elasticity modulus similar to root dentin in order to distribute the applied forces evenly along the length of the post and the root. 17,23 The threaded posts tested in this study have a high elasticity modulus, resulting in stress concentration at the root canal walls at the post thread end (Figures 2B and 2C). Stress concentration accounted for crack formation and propagation to the external surface of the root, resulting in root fracture.…”

“…those of dentin, [15][16][17] a wide variety of threaded posts continue to be used in restoring endodontically treated teeth. A threaded post system has the advantage of providing greater retention than passive posts, because the threads actively engage the dentin wall.…”

Enhanced aesthetics with metal-free ceramics and post systems—case reports

“…The results of in vitro and in vivo studies indicate that glass-fibre post restored root will be less prone to fracture because fracture risk of composite core and post were higher than those of root. 4 With a modulus of elasticity similar to dentin, the fibre post can reduce the concentration of stress and thus the rate of catastrophic root fracture compared with cast posts. 5 Non-metal posts can be used when coronal dentin remains and the crown is well supported by the remaining tooth structure.…”

Effect of cementation protocol on push-out bond strength of fiber posts to root canal

“…Despite these advantages, proper luting procedures of fiber posts are essential to the longevity of the restoration. In addition to the loss of post retention, debonding of the fiber post to root canal dentin increases the risk of post/core fracture [5].…”