Implant Angulations Effect on Bone Stresses: Clinical and FEA Study

Abstract

Although, dental implants are excellent prosthetic treatment option, implant complications do occur. To evaluate the effect of different implant angulations on the displacements and stress distributions on the implants, surrounding bone and its clinical consequences. Twenty-seven implants were placed in twelve patients. Cone Beam CT was used preoperatively to plan implant placement and post operatively to evaluate the actual implants positions. Finite element analysis was achieved using standard implant for a parametric study. A load of 100 N was applied at four different angulations relative to the long axis of the implant. Implant angulation discrepancies ranged from 0.7 - 32.6 degrees with mean value of 9.0 degrees. Axial displacement at loading angles zero-30 was; implants 4.02 - 4.6 micron, spongy bone 2.67 - 4.03 microns, compact bone 2.56 - 4.46 microns. While compressive stress in spongy bone increased from 2.2 to 4.2 MPa, and similar trend was observed for the other stress types in implant, cortical and spongy bone. The increase of stresses was directly proportional to the increase in implant angulations. Also, loading angulations may increase lateral displacement of implant which may explain the bone resorption in more angulated implants