Evaluation of the stress distrubition of force applied to different implant designs on implant and surrounding tissues by finite element analysis in bone defect models

Nowadays the application of dental implants has become an important option in the treatment of tooth loss due to various reasons. Various complications and/or peri-implant defects seen with the extencive use of dental implants may result in implant removal. It can be initiate a process that includes implant removal, re-implantation and/or regenerative applications. It is important to constitute an appropriate treatment plan for each patient by evaluating anatomical conditions, implant design, the amount of bone around the implant and bone quality. The aim of this study, the evaluation the stress and effect of the torque force applied to various implant models in the implant surroundings bone defects created in different bone types on the implant and bone by using finite element analysis method. Four different design implants were placed in the D2 and D3 featured bone. Total of 32 models were obtained by creating three different peri-implant defects around each implant and a control group without defects. By applying a reverse torque force of 10 Ncm on the implants in these models, von Mises, which occurs on the implant surface, cortical and cancellous bone around the implant, has been examined by comparing the stress distributions of the maximum principle and the minimum principle. As a result of the stress analysis, it was observed that the implant thread shape affected the stresses on the cortical bone more, but the stresses on the cancellous bone changed independently of the implant thread shape. It was observed that the change in the thread pitch of the implant affects the tensile stresses. In cancellous bone, a direct relation was found between the increase in thread pitch and tensile stresses. Among the created buccal, horizontal and circular peri-implant defect models, it is seen that the stress on the buccal defect models for both the upper and lower jaw models is higher than the horizontal, circular defect and control models, especially in the cervical region. As a result of the data obtained from this thesis, it can be thought that the stresses created on both the implant and the bone during the implant removal process may affect the re-implantation time. However, the data obtained by the finite element analysis method provide information about the general mechanism under limited conditions, and it is recommended to be supported by clinical studies.