Investigation of different implant systems used in the rehabilitation of the double-sided atrophic edented mandibular by fine element analysis of the stress created in the environmental tissues

For the rehabilitation of the severely atrophied mandible, implants applied with the "All on four" technique, use of short implants and subperiosteal implants are among the treatment options. These preferred methods have been presented as alternative methods to bone augmentation in the posterior atrophic mandible, because the risk of postoperative complications is low and the operations performed using a specially prepared guide for surgery can be performed with minimally invasive surgical techniques. In our study, atrophic mandible model was obtained by using tomographic records in computer environment. The aim of our study is to choose the most accurate surgical planning by applying dental and subperiosteal implants to this model, according to the stress values occurring in the surrounding tissues and implants under chewing forces. In our study, 4 different groups were planned. In group 1, two narrow diameter (3.3 mm diameter-10 mm length) dental implants on the right and left and one short dental implant perpendicularly, in group 2, 2 narrow diameter (3.3 mm) dental implants were applied to the anterior region with the "All on four" technique. diameter-10 mm length) implant, and 2 narrow diameter (3.3 mm diameter-12 mm length) implants in the posterior region, at an angle of 30°, in group 3, one short dental implant on the right and left, in addition to the group 2 model, in group 4. subperiosteal implant was applied. In our study, after dental implants and subperiosteal implants were applied, 150 N vertically and 100 N obliquely at an angle of 30 were applied to teeth 4-5-6. With the analyzes made, the tensions in the mandibular alveolar bone were measured as maximum and minimum principal stresses, and the tensions in the implants and metal infrastructure were measured as Von Mises stresses in MPa (N/mm2). As a result of our study; The stresses in the "All –on – four" group, which we created using narrow-diameter implants, were higher than the other groups. Short implants used in addition to this group; It has been observed that the stresses on the implants, bone and metal infrastructure are significantly reduced. In all groups, the group with the lowest max principal and min principal stress values on the alveolar bone was observed in the group in which subperiosteal implant was used.