Comparative Evaluation of the Shear Bond Strength and Mode of Fracture of Different Core Materials - An in Vitro Study

Background: Core build up is one of the important steps in the success of root canal treatment. It serves to restore severely damaged teeth, and become an integral part of the tooth structure. Mastication is related to the shear phenomenon, and shear bond strength measures the bond between the restorative material and tooth. Hence, the present study aimed at evaluation of the shear bond strength of different core build up materials using universal testing machine and mode of fracture using Scanning Electron Microscope. Objectives: To compare and evaluate the shear bond strength of different core build up materials. Materials and methods: A total of 20 human molars were selected and were decoronated at the level of CEJ. They were randomly divided into 4 groups (n=5) and core build up was done with all groups. Group 1 MultiCore, Group 2 Rebuilda DC, Group 3 Type 9 GIC, Group 4 Miracle Mix. After core build up was done samples of all groups were loaded in the Universal Testing Machine to evaluate the shear bond strength. Later the samples were evaluated for mode of fracture using Scanning Electron Microscope. Results: MultiCore and Rebilda DC showed maximum shear bond strength and cohesive failures. Conclusion: MultiCore and Rebilda DC showed maximum shear bond strength and cohesive failures followed by GIC. Miracle mix showed least SBS and maximum adhesive failure.