FE-analysis of dental implants with sinus lift

Patients with a reduced quantity and height of alveolar bone in the maxilla need a sinus lift operation to insert dental implants with acceptable chances of success. In the present investigation this standard procedure was modified by introducing a cortical bloc bone graft for the purpose of augmentation. The cortical bone graft lies in the upper third of the implants in the sinus. The method is indicated in the presence of less than 3-4 mm of alveolar bone. When the a lift is performed exclusively with bone graft granulate as substitute, adequate stability of the implant is not achieved in all cases even when using a two-step implantation procedure and a longer waiting period. This is manifested by a very short moment of torque during application of the implants. Double anchorage of the implants in alveolar bone and in the bone graft ensures ideal stabilization and fixation of the implants during the process of healing and thereafter. Minimization of loss rates should be achieved with this approach. Based on a finite element study (FE) we will investigate different distributions of tensions caused by chewing forces, when acting on the implants in a sinus lift with a cortical bone bloc graft in the region of the augmentation. The resulting stability of the implants will be demonstrated using biomechanical procedures. © 2009 Springer-Verlag.