Comparative Evaluation of Fracture Resistance of Teeth with Different Intraorifice Barriers after Bleaching

The aim and objective of this study is to compare and evaluate the fracture resistance of roots obturated with guttapercha different Intra orifice barriers after bleaching. Forty Human single canal extracted Maxillary Central Incisor, root canal preparation and obturation are done. Except for control group specimens, the coronal 3 mm of root fillings of all other group specimens will be removed with the aid of heated finger plugger and verified with the help of Williams periodontal probe. Obturated specimens will be divided with respect to the intra orifice barrier material- using Universal restorative composite (Filtek Z 350 XT), Light cure GIC (Fuji II LC, GC America) and Flowable hybrid (Filtek Z350 XT flowable composite) composite placed over the root canal fillings. (n=10). Groups will be submitted to internal bleaching with Sodium perborate- powder mixed with Hydrogen peroxide 6 % w/v. Axial compressive fracture strength testing was performed in a universal testing machine at a crosshead speed of 1mm/min and values recorded in Newton. According to the present study, the presence of intra orifice barriers strengthen the fracture resistance of endodontically treated teeth as compared to endodontically treated teeth without intra orifice barriers. RMGIC and Flowable composite proved to provide better fracture resistance than universal restorative composites. Intra orifice barriers provide not only the fracture resistance but also the coronal sealing, so it will definitely boost the treatment outcome of the root canal treated teeth