Considerable controversy exists regarding the ideal choice of material and design of post and core to improve fracture resistance in post-core-restored teeth. One study recommended endodontic posts of high modulus, while another study supported posts having a modulus of elasticity close to that of dentine. It is believed that carbon and glass fiber posts have a transverse elastic modulus that is close to that of dentin and therefore are less damaging to the remaining tooth structure.In vitro studies have shown elastic posts to have a lower tendency to cause root fracture than posts of higher stiffness. Nevertheless, the reinforcement effect after cementation of a complete crown with ferrule effect makes the difference between stiff and elastic posts less obvious. It has been demonstrated that there was no significant difference in fracture resistance between teeth restored with four post and core systems: serrated, parallel-sided, cast posts, and cores; prefabricated, stainless steel, serrated and parallel-sided posts, and resin-composite cores; prefabricated carbon fiber posts and resin-composite cores; and ceramic posts and resin-composite cores.
