Influence of Morse Taper Angle and Bone Quality on the Biomechanical Behavior of Dental Implants: A Finite Element Analysis Study

This study performed a finite element analysis to evaluate the biomechanical effects of implant connection geometry and bone quality (D2, D4) on stress distribution and structural stability. A mandibular model consisting of cortical and cancellous bone was generated, and implant components—including fixture, abutment, screw, and crown—were simulated. Two designs were analyzed based on Morse taper angle (11° or 15°) and the presence of an apical slot. A tightening torque of 32 N·cm and an occlusal load of 200 N were applied, with the lateral mandible constrained. The 11° taper with the non-slot design showed the highest von Mises stress (1048.81 MPa) in the fixture with D4 bone type and Tessera crown. In contrast, the 15° taper with the slot design improved stress distribution at the fixture–abutment interface, reducing fixture stress by 26.78% in D2 bone type. Localized stress near the slot was observed but did not compromise overall structural stability. Under oblique loading, stress concentrated primarily in the cortical bone, whereas D4 cancellous bone showed increased susceptibility to microdamage. Prosthetic materials demonstrated no significant differences in stress behavior. These findings suggest that connection design and bone density strongly influence biomechanical performance and should guide individualized implant selection.