Purpose: To evaluate the impact of dental materials on stress concentration and distribution in inlay restorations and the tooth. Materials and methods: A maxillary premolar model was developed to investigate the stress concentration and distribution within the inlay restorations and the tooth. The three-dimensional inlay cavity designs featured dimensions of 2.7 mm in depth, 2.3 mm in isthmus width, and 1.2 mm in gingival wall width. Three types of restoration materials were examined: conventional composite for direct inlay restorations, and full ceramic and indirect composite for indirect inlay restorations. A load of 250 N was applied to the tooth, and stress levels were quantified using von Mises stress values. Results: The highest stress concentration occurred in the direct composite restoration (371 MPa). The stress levels for the indirect composite and ceramic were 367 and 368 MPa, respectively. Within the tooth structure, stress levels measured 148 MPa for direct composite and 108 MPa for indirect composite. The ceramic restoration distributed the lowest stress values at 41.7 MPa. At the resin cement layer, stress concentrations were 19.5 MPa for direct composite, 16.4 MPa for indirect composite, and 7.17 MPa for ceramic restoration. Conclusion: The choice of restoration material influenced the stress levels in both the restoration and the tooth. Ceramics emerged as a more appropriate material for inlay restorations, while indirect composite also offered a viable alternative for inlays.