The fracture resistance of structurally compromised roots using different post systems

Abstract

The structurally compromised root presents a great challenge to the restorative dentist. The amount of tooth structure that remains after endodontic therapy and post preparation is of prime importance and the strength of an endodontically treated tooth is directly related to the amount of residual dentine. Post and cores are often required with pulpless teeth to provide retention and resistance form for the final restoration. Aim: The purpose of this in vitro study is to investigate the fracture resistance of structurally compromised teeth using four dynamically different post and core systems in the rehabilitation process. Method: After the crowns were removed one specimens were then randomly divided into four groups of 25 teeth each as follow: Group A: morphologic cast post and core; Group B: resin reinforced glass-fibre post and composite core; Group C: resin reinforced carbon fibre post with composite core and Group D: resin reinforced prefabricated parallelsided titanium post and composite core. All specimens were subjected to an increasing palatal force until fracture occurred. Results: Results showed cast post and cores to have higher fracture loads that the resin reinforced groups (p< 0). The difference in fracture resistance between the three reinforced groups was found not to be significant (p > 0). Conclusions: Significantly higher fracture thresholds were obtained in the cast post-and-core group. The reinforced group (with composite cores) showed failure of the post-core interface before the fracture of the tooth occurred. This failure occurred in response to acceptable high loads. The Luminex@ light transmitting posts can help strengthen weakened, endodontically treated teeth by the combined bonding action of dentine bonding agents and composite resin restorative material.