Joshi, NiranjanQuqandi, Rufaida2023-06-202023-06-202023https://hdl.handle.net/20.500.14154/68416Methods: Twenty-seven extracted premolars were assigned randomly into three different groups; Control Group1 (G1): Prefabricated glass fiber posts with 2-mm ferrule, Group2 (G2): Prefabricated glass fiber posts with no ferrule, and Group3 (G3): Endocrown with no ferrule. All groups received endodontic treatment followed by Lithium Disilicate restoration that was adhesively luted using 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP) containing resin cement. Each group underwent thermocycling of 10,000 cycles at 5oC and 55oC for 30 seconds in each bath. Specimens were subjected to a cyclic fatigue test for 840,000 cycles while being immersed in distilled water. Specimens that survived the mechanical fatigue testing were loaded-to-failure and failure mode was analyzed. Results: All samples survived the mechanical cyclic fatigue testing without any evident failure. The one-way ANOVA showed statistical significance between the fracture resistance of the groups (p = < 0.05). Tukey’s pairwise comparison test revealed a statistically significant difference between the fracture resistance of the control group (G1) in comparison to (G2) and (G3) (p < 0.05) and no statistical significance between (G2) and (G3) (P < 0.862). All groups showed the highest rate of favorable failure modes. Conclusion: Endocrowns displayed reliability as an alternative restorative treatment option for patients with severely compromised endodontically treated premolars as they are a fast, reliable, minimally invasive, and cost-effective treatment option compared to conventional treatment of post, core, and crown.61en-USEndocrownPost and coreFerruleEndodontically treated teethCAD/CAMDigital dentistryBonding10-MDPAdhesive dentistryCyclic fatiguePremolarsThesis