## 3 Results  
To evaluate the mechanical stability of the implant fixture in bone tissue, the maximum von Mises stress and stress distribution were analyzed, and to evaluate the biomechanical effect in the bone tissue around the implant, the maximum von Mises stress and fatigue failure analysis was performed. In the fatigue failure criterion (>3000 \(\mu\epsilon\)), the bone remodeling rate cannot keep up with the microdamage rate. In other words, microfractures continue to occur, and the bone healing mechanism loses the time and ability to recover them [41]. Figure 3 shows the maximum von Mises stress values and stress distribution areas of the implant fixture according to bone quality and peri-implant bone loss. The maximum von Mises stress of the implant fixture was higher in low-quality bone than in normal bone, regardless of the amount of bone loss. The stress of the fixture gradually increased as bone loss increased in both normal and low-quality bone. The highest von Mises stress was observed in the model with 5 mm of bone loss in low-quality bone, and the stress value was 218.05 MPa. In the normal bone, when bone loss occurred from 0 mm to 5 mm, the maximum stress value of the fixture showed a stress increase rate of approximately 36.95%, and in the low-quality bone, it showed an increase rate of approximately 74.90%. This indicates that the stress increase in the fixture due to bone loss was more pronounced in low-quality bone. The maximum von Mises stress difference between normal and low-quality bone was minimal when bone loss was 0 to 2 mm. However, when bone loss exceeded 3 mm, the stress difference between the two bones became significant. This indicates that a significant difference in stress distribution occurs when bone loss exceeds a certain level. As bone loss progresses, the vulnerability of defective bone may become more prominent. Figure 4 shows the maximum von Mises stress values and stress distribution areas of cortical and cancellous bone according to bone quality and peri-implant bone loss. The highest von Mises stress in the cortical bone surrounding the implant was observed when the bone loss was 2 mm in the low-quality bone, with a stress value of 60.88 MPa. Regardless of the amount of bone loss, the stress value of the cortical bone was higher in the low-quality bone than in the normal-quality bone. As bone loss progressed from 0 mm to 2 mm, the maximum von Mises stress of the cortical bone gradually increased. In the normal-quality bone, the stress increased from 21.45 MPa to 47.33 MPa; in the low-quality bone, the stress increased from 22.29 MPa to 60.88 MPa. When bone loss progressed to 3 mm or more, the cortical bone surrounding the implant was lost, and the maximum von Mises stress of the cortical bone rapidly decreased. The highest von Mises stress in cancellous bone was observed when the bone loss was 5 mm in the low-quality bone,  
Figure 3: Distribution area and maximum value of the von Mises stress of the implant fixture. with a stress value of 60.88 MPa. Similar to cortical bone, the maximum von Mises stress in cancellous bone was higher in the low-quality bone than in the normal bone model, regardless of the amount of bone loss. However, the difference in stress values between the normal- and low-quality bone was not significant overall. The maximum von Mises stress of cancellous bone increased slightly as bone loss progressed from 0 mm to 2 mm and from 3 mm to 5 mm, but the difference was insignificant. As bone loss progressed from 2 mm to 3 mm, the stress value of cancellous bone increased rapidly from 5.10 MPa to 9.85 MPa in normal bone and from 5.96 MPa to 10.58 MPa in low-quality bone, compared to other bone loss increase sections. Figure 5 show the distribution and volume fraction of the fatigue failure area of cortical and cancellous bone according to bone quality and peri-implant bone loss. The fatigue failure area was distributed around the cancellous bone surrounding the implant.