## 4 Discussion
The results of the present study indicate that the stress distribution in Bone-Level and Tissue-Level implants is strongly influenced by the implant-abutment contact area. However, direct comparisons with previous finite-element analyses (FEAs) should be made cautiously due to differences in implant design, boundary conditions, and modeling approaches. For instance, a prior FEA study that simulated a 200 N occlusal load in various directions reported higher stress levels in Bone-Level implants compared to Tissue-Level implants [24]. However, several key differences exist between that study and the present one. First, their implant-abutment connection was designed using an idealized CAD model, whereas our study utilized real measurements obtained through microscopy. This distinction is critical, as real-world connections often introduce microgaps and irregularities that affect stress distribution. Additionally, their loading setup differed from our oblique force application, which may account for the discrepancy in the results. Similarly, another FEA study [25] reported that Bone-Level implants exhibited higher stress peaks than Tissue-Level implants. However, their analysis focused on Osstem implants, which differ significantly from the Straumann implants used in our study. Notably, the Osstem Tissue-Level implant features an abutment that partially rests on the implant platform, whereas the Straumann design does not. Additionally, the Bone-Level implant in their study had an abutment wider than the implant diameter, altering the load transmission characteristics. Furthermore, differences in the prosthetic screw design across implant brands may also influence force distribution and stress concentration. Given these variations in implant geometry, connection design, and modeling methodologies, it is important to interpret comparisons with caution. Our findings emphasize the importance of implant-abutment fit in reducing stress levels, particularly in Tissue-Level implants. Future research should explore how these factors influence long-term mechanical stability, incorporating experimental validation to complement FEA findings. In addition to computational analysis, in vitro studies are also important. A previous in vitro study evaluated the internal fit and cyclic fatigue life of three implant-abutment configurations, comparing original and alternative replicated cast-to-gold abutments [26]. They found that original abutments transferred occlusal loads more homogeneously because of better fitting with internal components. The present study corroborates this, showing that a Standard connection leads to 13% lower stress than a Partially connected abutment, especially when Tissue-Level implants are used. A prior finite-element study analyzed the strain and stress distribution surrounding Standard and short posterior implants [27]. They investigated the vertical and oblique loading of 365 N for the molars and 200 N for the premolars at 30\({}^{\circ}\) in abutments and implants of three brands. They found that the stress and strain in trabecular and cortical bone were improved when the implant had an internal hexagon design, showing that a perfect fit between the implant and abutment reduces stress. This corroborates the present results which showed that the stress was lower when the internal connection was standard. Comparing BL and TL implants, however, it seems that the height of the implant can affect the outcome. According to a previous FEA study, short implants led to BL implants generating higher overall stress values compared to TL implants, though these values were still below the threshold for fracture, suggesting that short implants can be a viable treatment option for patients unable to undergo more invasive surgeries. However, quantitative results for the prosthetic screw cannot compared with the present investigation [28]. Despite differences in the mechanical response, a clinical trial assessed peri-implant mucositis (PM) in Tissue-Level (TL) and Bone-Level (BL) implants after non-surgical debridement.