Comparison of Short Implant, Angled Implant, Distal Extension and Grafting Methods for Atrophic Maxillary Posterior Region: a Finite Element Study

The objective of the study was to determine the most ideal of four different implant-prosthesis treatment combinations that can be used for the posterior maxilla by using the finite element method.

Among the four models representing the posterior region of the atrophic maxilla, in the first model, a standard implant was installed in the place of tooth 4, while a short implant was inserted in the place of tooth 6 due to increased sinus pneumatization. In the second model, standard implants were placed in tooth 4 and 5 and the implant in tooth 5 was installed with 30° distal inclination so as to tangentially cross the sinus region. In the third model, a graft application was designed for the area with increased sinus pneumatization, and standard implants were inserted in the places of tooth 4 and 6. In the fourth model, two standard implants were placed at teeth 4 and 5 and a distal extension was made in between.

The maximum and minimum principal strain values in cortical bone were obtained as 2594 µε and 5478 µε in Model 4, respectively, and in trabecular bone as 4733 µε and 3761 µε in Model 1. Among the implants and abutments, the highest von Mises stress value of 709 MPa occurred in Model 4.

The third model that features a graft was the most successful model and the fourth model that featured distal extension had the highest likelihood of damage.