## 4 Discussion
In both 1 mm and 2 mm subcrestal models, a reduction in stress was observed in the cortical area. This finding suggests that, in scenarios where patients are subjected to occlusal loads, such as parafunctions, a subcrestal positioning would be more advantageous compared to an equicrestal positioning. This analysis allowed us to understand the factors that must be considered when choosing the depth of insertion of the implant. It is important to highlight that subcrestal placement stresses a significant portion of the trabecular bone, aligning with the findings of [PERSON] et al. [37]. This supports the notion that appropriately stimulated bone can undergo reshaping along the implant surface. The FEM analysis helped these researchers in understanding that when implant positioning occurred subcrestally at about 1 mm, the transfer of load was more beneficial for bone growth when compared to cases where the insertion depth was greater. The reason can be linked to the fact that in this latter scenario, a higher amount of tension was absorbed, resulting in a notable reduction of tension within the trabecular bone, which did not favor new bone formation. FEM analysis is a powerful simulation tool that allows you to evaluate structural behavior and stresses in a variety of situations [48; 49]. However, like any modelling and simulation tool, there are some limitations that are important to consider when using FEA to assess stress variations. Among them, we find the accuracy of the input data. In fact, the accuracy of FEM analysis results depends on the quality of the input data used, such as loading conditions and material properties. With respect to this last point, all materials were considered homogeneous, isotropic, and linearly elastic, although the mandibular cortical bone was crosswise isotropic and inhomogeneous. Alternatively, considering the materials as anisotropic, with mechanical properties that vary in different directions, they would require the use of more sophisticated and complex FEA models and the consideration of additional parameters to describe and determine the mechanical behavior of the material. Therefore, simplifying a material as isotropic can be an approximation and may not fully reflect the actual behavior of the material. In general, the choice to consider a material as isotropic or anisotropic depends on the specific characteristics of the material and application, as well as the objective of the FEA analysis. It is important to carefully consider which approach is most appropriate to obtain accurate and representative results. However, it also holds significance to take into account the morphology, density, and concentration of the trabeculae, in order to determine their influence on the results obtained from FEA simulations. In addition, simplifications have also been made with regard to geometry. These simplifications may affect the final results and may not consider all the real interactions between components. Despite this, for the purpose of simplification, these properties were disregarded in the modelling of this study. Other two identified factors that influenced the simulation were the material used for the implant and the surface roughness. The optimal properties of the implant material allow for increase in the bone regeneration process and, hence, the early stabilization of the implant [48; 49]. Instead, the increased roughness of the surface in turn increased the coefficient of friction between the surface of the material [50]. In this FEA study, details of the implant surface roughness have been ignored since the study aim focused only on the effect of tensions within the bone. Although FEA studies have been previously employed to anticipate the biomechanical performance of different implant designs and examine the impact of clinical factors on the success of implants, there is still a need to comprehensively assess and understand the correlation between numerous variables for long-term implant success, aiming to enhance clinical results.