## 3 Results
**(c)** At 600 N, the stress becomes more intense, with some values exceeding 1.50 \(\times\) 10\({}^{12}\) Pa. More peaks and abrupt variations appear, indicating that the material is being pushed beyond normal limits, increasing the risk of cracking. **(d)** At 800 N, stress levels are the highest—with peaks over 2.00 \(\times\) 10\({}^{12}\) Pa—and the distribution is highly fragmented. The material is under overload and faces a real risk of failure or fracture. Table 3 summarizes the values obtained for the integrated average stress and the safety factor (SF), calculated as the ratio between the compressive strength of the amalgam (483 MPa) and the average stress obtained in each loading scenario. To evaluate the mechanical behavior of the restorations made with the composite material, the same methodology of volumetric integration of von Mises stresses was applied as for the amalgam (Table 4). The four axial loading scenarios were used to replicate the functional and parafunctional conditions within the oral cavity. The results indicated a higher average stress in the composite compared to the amalgam at all force levels, suggesting a reduced ability of the composite material to uniformly disperse mechanical stress. At a force of 800 N, the average stress in the composite mass was 7.2 \(\times\) 10\({}^{8}\) Pa, compared with 6.08 \(\times\) 10\({}^{8}\) Pa in the amalgam--a biomechanically significant difference. These results highlight the superior mechanical stability of the amalgam compared to the composite under identical loading conditions. Although the calculated SF values remain below the ideal threshold, the amalgam consistently exhibited lower average von Mises stress values at all force levels, indicating a better ability to distribute and absorb mechanical loads. This suggests that amalgam has a higher resistance to repetitive or intense occlusal forces without approaching the material's critical failure limits. In the case of the composite material (Figure 11a), the stresses generated by the applied force penetrated deeply into the restoration, with the maximum values reaching 3.05 GPa. The stress distribution was clearly more extensive in depth, indicating the internal transmission of the mechanical loads throughout the restorative material mass. This characteristic suggests that the structure of the composite allows for more pronounced elastic deformations but also presents a potential for stress accumulation in regions farther from the contact surface. Such a phenomenon may increase the risk of internal microcrack formation or debonding at the interface with the dental tissue. \begin{table}
\begin{tabular}{c c c} \hline
**Applied Force (N)** & **Average Stress (Pa)** & **SF—Composite** \\ \hline
200 & 1.9 \(\times\) 10\({}^{8}\) & 1.43 \\ \hline
400 & 3.95 \(\times\) 10\({}^{8}\) & 0.8 \\ \hline
600 & 5.6 \(\times\) 10\({}^{8}\) & 0.66 \\ \hline
800 & 7.25 \(\times\) 10\({}^{8}\) & 0.34 \\ \hline \end{tabular}
\end{table} 
Table 4: Average von Mises stress and safety factor (SF) values for composite restorations under increasing masticatory loads (200–800 N). \begin{table}
\begin{tabular}{c c c} \hline
**Applied Force (N)** & **Average Stress (Pa)** & **SF—Amalgam** \\ \hline
200 & 1.52 \(\times\) 10\({}^{11}\) & 2.27 \\ \hline
400 & 3.03 \(\times\) 10\({}^{11}\) & 1.55 \\ \hline
600 & 4.56 \(\times\) 10\({}^{11}\) & 1.17 \\ \hline
800 & 6.08 \(\times\) 10\({}^{11}\) & 0.83 \\ \hline \end{tabular}
\end{table} 
Table 3: Average von Mises stress and safety factor (SF) values for amalgam restorations under increasing masticatory loads (200–800 N). In contrast, Figure 11b, corresponding to the amalgam restoration, shows a more superficial stress distribution, with a significantly lower maximum value of 1.716 GPa. The stress zone is concentrated almost exclusively in the upper layer of the material, confirming the more rigid behavior of the amalgam.