Date of Award
Master of Science (MS)
Introduction: This study aimed to develop a 3-D finite elemental analysis (FEA) model and digitally incorporate a crack into this model. After model development, this study compared the load required to propagate this crack in a mandibular molar with 3 different endodontic cavity designs using FEA. Methods: 3-D printed mandibular first molars (Endo 3DP; Acadental, Lenexa, KS) were accessed with 3 different access cavities: a traditional access cavity (TRC), a ninja access cavity (NAC), and a truss access cavity (TUC). The teeth were instrumented to EndoSequence #35/.04 in the MB and ML canals and #40/.04 in the D canal. Each access was restored with composite at the level of the CEJ to the occlusal surface. After restoration, each tooth was scanned by micro-computed tomographic (micro-CT) imaging and stereolithic meshes were developed to allow for design and incorporation of a crack and FEA. One distal marginal ridge crack was digitally designed and incorporated into the model. The crack extended from the occlusal surface to 2mm above the CEJ. Each load cycle had a total of 247 N applied to 4 different occlusal points to simulate masticatory load. After FEA, the total number of loading cycles to induce crack propagation with the various models were compared. Results: The total number of loading cycles required to induce crack propagation of a similar extension was 12,146,000 cycles for the TUC model, 5,250,500 cycles for the NAC model, and 4,320,700 cycles for the TAC model. Conclusions: Based on this FEA study, the truss access cavity required the most load cycles to reach the same crack extension as the other models. The ninja cavity required slightly more load cycles than the traditional access cavity of a similar crack extension.
Available for download on Friday, April 11, 2025