## 4 Discussion  
Earlier research reported that Morse tapers can be susceptible to the occurrence of complications. This is justified because implants are vulnerable to fracture with extended usage, and an insufficient implant-abutment joint is one of the many reasons that can facilitate this [12]. To understand fracture mechanics and stress magnitude, several studies have applied finite element analysis (FEA) to evaluate the biomechanical response. Regardless of the limitations of this method, FEA is fundamental to providing information concerning mechanical failures and stress-strain distribution. A former finite element study investigated the effect of different prostheses with misfits on the distribution of stress, implant structures, and adjacent bone [20]. They found that occlusal loads near the gap increased the stress in implant structures and peri-implant bone tissue. This corroborates the present study, which showed higher stress levels when the connection was Partial. However, the present study did not evaluate adjacent bone. Additionally, their model had a different implant design, which was from the company Nobel Biocare. It is important to mention that they also used other boundary conditions, which were different in magnitude and direction from the oblique load simulated in this research. The results of this study corroborate another previous article which showed that Tissue-Level implants displayed more stress in the surrounding bone than Bone-Level implants [21]. This can be explained because Tissue-Level implants have a shorter screw nearby the cervical area and a thinner axial wall than the Bone-Level implant, which can lead to higher stress levels in the surrounding bone. This previous article [21] also showed that Tissue-Level implants were associated with more bone remodeling in the cortical bone. Complementary to [20]'s findings, this research investigated stress in the implants with different implant-abutment contact surfaces, reinforcing the importance of a good implant-abutment connection. A previous study aimed to predict time-dependent bone remodeling around Tissue-Level and Bone-Level implants used in patients with partial bone width. They found that the Tissue-Level implants had higher stresses than the Bone-Level implants [22]. According to the authors, the Bone-Level implants had lower displacement than the Tissue-Level implants, showing that the force distribution was better in the second one [22]. The present study showed a similar biomechanical response when comparing both implant designs. However, it is important to mention that the present study did not measure the stress in the bone tissue. Instead, the stress was calculated between the components. Based on these previous reports [21; 22] and the results presented in this study, we can expect more mechanical failures for Tissue-Level implants in comparison to Bone-Level implants. A prior finite-element study analyzed the effect of discrepancy in implant-level fixed partial dentures and marginal bone support on the generation of implant fractures [23]. The misfit groups had higher coronal body stress levels than the no-misfit groups, which supports the present study's findings, which showed higher stress when the connection was partial, especially with the Tissue-Level implant. In addition, the authors reported that the effective stress was higher in the conical connection in the group with bone loss. It is essential to note that the prior study used an Astra Tech Implant System Osseospeed TX from the company Dentsply Sirona. They considered a misfit when there was a certain distance between structures, while the present study considered the connection partial when the internal implant structures were not ideally touching. It is also important to mention that the present study did not measure marginal bone support and did not use a framework on top of the abutment. In summary, the importance of the internal connection besides the external fit for reducing stress levels is evident.