Investigating the Effect of Different Implant-Abutment Connection Angles on the Stress Distribution of the Implant System Using the Finite Element Method

 Titanium implants are widely used due to their mechanical properties in jawbones. Many studies have shown the success of dental implants in the treatment of edentulous and partially edentulous mandible and maxilla.

Methods and Materials:

 Three types of implant-abutment internal hexagonal connections with angles of 8, 11, and 16 degrees were designed for this study. All the samples had identical dimensions except the angle of connection. Ceno-Bonemodels were designed and built based on CBCT from mandible by CAD-CAM with dimensions of 20 mm height, 10 mm crowding, and 10 mm buccolingual. The implant-abutment set was placed within the designed block. All samples were put under occlusal vertical force 200N (load type1) and non-vertical force 200N with an angle of about15 buccolingual degrees (Load type2) and applied precisely to the center of the occlusal crown. Each model was analyzed according to the material characteristics used, and the obtained Von Miss Stress was recorded.

 Except for the implant and the connection angle of 8 degrees, in other cases, increasing the angle of applied force increased maximum stress values. By increasing the connection angle in axial force and angular force, the stress in the abutment, screw, and implant increased and decreased in the surrounding bone.

 Angled forces increase stress on the abutment, retaining screw and bone. The connection point angle of the implant-abutment increases stresses in the abutment, implant, and retaining screw and decreases stress in the surrounding bone.