Comparison of Resistance to Fracture of Endodontically Treated Teeth Reinforced with Various Posts: An In-vitro Study

Introduction: Endodontically treated tooth reinforced with posts should restore its lost structural integrity, as well as withstand the various masticatory forces. Choosing the appropriate post, so that a durable prosthesis can be given, is often a challenge to a restorative dentist.Aim: To compare the resistance to fracture, of endodontically treated teeth restored with the various posts when subjected to compressive loads, and analyse the different types of fractures and cracks which are visible under normal eye, microscope and radiograph.Materials and Methods: An in-vitro study was conducted in the Department of Dentistry, Pondicherry Institute of Medical Sciences, Puducherry, India, from February 2019 to March 2020. Study was done with four types of posts namely cast post, stainless steel, fibre and titanium on seventy extracted teeth, which were randomly allocated into five groups with one group as control without any post. The teeth were subjected to increasing compressive loads with universal testing machine and the loads at which fracture occurred was recorded. The data was analysed statistically with one way Analysis of Variance (ANOVA) and the groups were compared with Tukey's HSD test. The types of fractures that occurred were also analysed. Results: The loads at which the teeth reinforced with various posts fractured, showed significant difference (p-value <0.0001). The mean load at which fracture occurred for teeth restored without any posts was 711.6086 N and teeth with stainless steel post was highest at 1605.955 N. Those with titanium posts were found to have minimum microcracks (14.2%) when seen under dissection microscope. Maximum number of teeth with titanium posts had favourable fracture and withstood the load (64.29%), with fracture occurring only at root tip and no fracture elsewhere. Tukey's HSD test was done to compare the fracture resistance between the groups at 0.05 level of significance. There was no significant difference in the load at which fracture occurred between groups.Conclusion: In the present study, of all different post and core materials, stainless steel post resisted highest load and titanium posts had favourable fractures.