iarjmsIARJMSIARJMS2708-3594https://doi.org/10.47310/iarjms.2021.v02i02.027Finite Element Fatigue Analysis in Restored Premolars with Bulk and Incremental TechniquesAims: A premolar, a lower premolar with a class II cavity filled with bulk resin and a lower premolar with a class II cavity filled with nanocomposite resin were prepared using an incremental technique. Introduction:The selection of restoration material in dentistry represents a challenge to obtain successful treatment. The biomechanical properties of composites influence the longevity of a restoration. Methods: Three situations were simulated for each of the tested models by means of the three-dimensional finite element method: 1. Mastication (200 N axial force) in the functional area of ​​the occlusal faces; 2. Swallowing (axial force 200 N) at 5 stable points on the occlusal faces; and 3. Deflection (600 N horizontal force) at 1 point of the vestibular cusp. Results: The bulk resin obtained a better stress distribution under chewing, swallowing and deflection forces than the nanocomposite resin. Conclusion: The hypothesis was verified: the premolar tooth with cavity class II filled with bulk resin showed lower stress than the premolar tooth with cavity class II filled with nanocomposite resin.