In vitro study of fatigue test of pulpless teeth restored with three post-and-core systems

Objective:To compare the fatigue strength and failure pattern of extracted teeth restored with three different post-and-core systems.Method:The crowns of 24 extracted maxillary central incisors which accepted root canal therapy were amputated. The roots were divided into 3 groups, A, B and C randomly, the teeth of group A were restored with AESTHETI-PLUS fiber post-core-crown system, group B were restored with C-POST fiber post-core-crown system and the teeth of group C were restored with Cr-Co cast metal post-core-crown system. All the teeth were mounted in resin blocks. Loads were applied on the samples at 135 degrees and tested with fatigue test machine. Result: Two roots fracture in group A, C while the position of the fracture is different. The composite core of other 2 teeth of group A detached from the dentin of the root while there is no obvious failure of teeth or restorations of other 6 teeth of group C. One root of group B fractured at the level of mid-root and the composite core of a tooth in group B detached from the root dentin. Conclusion: Cr-Co cast metal system is a reliable post-core system that can match the clinical demands. Both kinds of fiber post have bright prospect in clinical use in the near future, however, the dentists should take other factors into account, such as the composite core of the system.