Effect of dentinal bonded resin post-core preparations on resistance to vertical root fracture.

An in vitro study was conducted to compare the resistance to failure of two restorative protocols for endodontically treated teeth. Half of 24 specimens received cemented cast post-core restorations and the other half were restored with dentin-bonded composite resin using the ferric oxalate, NTG-GMA, and the PMDM system developed by Bowen. The dentin-bonded resin post-core restorations provided significantly less resistance to failure than the cemented custom cast post-core. The dentin-bonded resin post-core fractured in every instance before the root fractured. A greater force was required to cause failure of the resin post as the cross-sectional area of the post increased.