Purpose: To compare fracture resistance and primary mode of failure of endodontically treated teeth with three different posts systems and two variant luting agents. Materials and Methods: Root canal treatment was performed on 40 maxillary incisors and samples were divided into 4 groups. For three experimental groups post space preparation was done and teeth were restored with cast post-core (Group B), prefabricated glass fibre post (everStick post) with composite core (Group C) and prefabricated zirconia posts with composite core (Group D). Control group (A) samples were selected with intact coronal structure. Post space was prepared in all samples. Two type of luting cements dual cure resin cement (Luxacore Z) and glass ionomer cement (Fuji I, GC) were used for post cementation. The core was standardized to 4mm × 5mm. Prepared samples were subjected to compressive load of 0.5mm/min at 135º angulation. The load at which fracture occurred and fracture mode were analysed statistically by one way ANOVA, post-hoc tukey test and chi-square test. Results: The findings showed statistically significant difference between failure loads. The mean load required to fracture glass fibre was highest (711MPa) and least for control group (231MPa). The glass fibre posts and zirconia posts showed favorable fracture. Conclusion: The results concluded that endodontically treated teeth without post core system showed least fracture resistance signifying need to reinforce tooth. Use of glass fibre post (everStick post) showed highest mean fracture resistance regardless of luting agent.
