## 4 Discussion  
The current study evaluates the stress and strain with the patient's bone condition in the case of full and partial osseointegration using the finite element method. Based on [PERSON]'s law, it is well known that bone adapts to stress generated by the load transmission from the implant which induces strain surrounding the bone. The magnitude of the strain is affected by several biomechanical factors, such as the implant material, the design of the implant, and the magnitude of the load applied. The two most common complications that currently exist in the field of implants are stress shielding and loss of osseointegration. Therefore, porous implants were designed with full and partial osseointegration, and their performances were investigated in normal and weak bones. The von Mises stresses of the implants are often calculated as they represent a good measure of the stress experienced by the implant. The results of such calculations demonstrate that the quality of a patient's bone can have a significant effect on the success of dental implants, with weaker bone resulting in higher levels of stress. Additionally, the stage of osseointegration (the process by which the implant fuses with the surrounding bone) is a key factor in determining the effectiveness of dental implants. It is worth noting that while dental implant failure is rare [47], it can still occur, particularly during the first five years after the implant is placed. However, modern dental implant technologies, particularly those made of titanium alloys, are considered to be the best option due to their superior biomechanical strength and biocompatibility [48]. Overall, while dental implants are generally a safe and effective option for replacing missing teeth, it is important to consider all factors that can affect their success and to seek out experienced and qualified dental professionals to perform the procedure. The analysis of implant displacements in cancellous bone has shown that increasing the porosity of the implant generates more micromovement in the surrounding bone. The stiffness of the implant also plays a role in determining the amount of displacement, with porous implants allowing for more displacement compared to dense titanium implants. While considering the distribution of stress in cancellous bone, the results indicate that in the case of full osseointegration (where the implant is fully fused with the surrounding bone), increasing the porosity of the implant leads to higher stresses being transferred to the surrounding bone. This means that decreasing the stiffness of the implant can result in the implant transferring more stress to the surrounding bone. However, in the case of partial osseointegration (where the implant is only partially fused with the surrounding bone), the opposite effect is observed. Decreasing the stiffness of the implant leads to  
Figure 8: Comparison of octahedral shear strain in normal and weak bones with different implants. lower stresses being transferred to the surrounding bone. Bulk titanium implants transfer more load to the surrounding bone compared to porous titanium implants. Moreover, there has been ongoing research in developing new implant materials and designs that can improve the osseointegration process and minimize the risk of implant failure [49]. For instance, new implant designs are being developed to promote faster and stronger boneingrowth [50]. Overall, the stiffness and porosity of implants play a role in determining the stress distribution and implant displacement in cancellous bone. The octahedral shear strain was calculated in this study to determine the bone response to dental implants, and the mechanostat hypothesis was used to interpret the results. The adapted state, which is the optimal state of bone adaptation to the implant, was found to include P31, P18, and P9 implants in normal bone for both partial and full osseointegration.