Biomechanical Finite Element Analysis of Short and Long Implants In Resorbed Maxillary Posterior Region

Objectives This study aimed to analyze different implant treatment concepts in maxillary posterior region. The effects of using short or long implants, with or without bone graft, are investigated in terms of strength and integrity. Materials and Methods Three different 3D models were generated from a CBCT scan: SI (short implant), LISG (long implant after sinus lifting with graft) and LIS (long implant after sinus lifting without graft). After integrating necessary implant parts, models were analyzed by FEM. The resultant stress values in the cortical and cancellous bones are evaluated by applying vertical and oblique forces. Implant parts are also investigated in terms of integrity and stability. Treatment concepts are compared depending on the FEA results. Results FEA demonstrated that short implants resulted in higher stress concentrations within the peri-implant bone compared to long implants. The maximum principal stress values in cortical bone were 100 MPa (tensile) and 133 MPa (compressive), while cancellous bone exhibited 14 MPa (tensile) and 16 MPa (compressive), all within physiological limits. Long implants, with or without grafts, significantly reduced stress levels compared to short implants. There were significant reductions for both compression and tensile stresses in the long implant concepts. Stress distribution patterns indicated that oblique loading led to increased palatal stress concentration. Conclusions Although the stresses occurring in the short implant concept are higher under both masticatory loading conditions, the results obtained for both short and long implant concepts remain within physiological limits where the bone can maintain its continuity without deformation. Clinical Relevance Short implants are biomechanically viable alternatives when augmentation is not feasible, provided that stress thresholds remain within safe limits.