Evaluation of Stress Distribution with Finite Element Analysis on and around Short Implants in Case of Inadequate Vertical Bone Quantity in Maxilla Posterior Region

Purpose: The aim of this study was to evaluate the stress distribution on the short implant and surrounding bone that was applied to posterior maxillary edentulous region. Methods: The model was defined according to a computed tomography images of a healthy patient’s posterior edentulous region with maxillary sinus pneumatization. Then, 6.5mm length and 4mm diameter cylindrical titanium implant was modeled. Vertical and oblique forces were simulated and evaluated with three-dimensionally finite element analysis method. Results: For evaluating the stresses on the implant during vertical and oblique loading, von Mises stress results were recorded both numerically and as colored images. Von Mises stress, compressive stress and tensile stress on the four regions determined on cortical bone and cancellous bone were evaluated with numerical and colored images. According to results; stresses were found to be high in the cortical bone compared to the cancellous bone. Also, the highest stress was found on the implant body, and the stress were high at near the abutment-implant junction, region of the implant adjacent to the cortical bone. Conclusion: It is predicted that the use of short implants in maxillary posterior region could be appropriate because the obtained stress values in all models were not high as the destructive limits. Taking into account that the stress on the implants generated by the oblique forces is higher, for especially short implant placement, it is important biomechanically that the implants should be placed as possible as parallel to the occlusal forces