Influence of number and angulation of implants to support fixed prosthesis in atrophic maxilla: comparative non-linear study using 3D finite element

Abstract

The aim of this study is to perform a non-linear analysis through tridimensional finite element method (FEM - 3D) to simulate the fixed prosthesis anchored at implants in atrophic maxillae varying the number of implants and the inclination of the distal implants, to obtain the maximum and minimum principal stress, shear stress and the deformation of the bone-implant interface. MATERIAL AND METHOD: Four mathematic models will be built based on a tomographic image of a patient with atrophic maxilla and moderate maxillary sinus pneumatization, by using software Mimics 11.11 (Materialise) and Solid Works (3Dtech). Four (M4) or six implants (M6) Cone Morse Alvim CM (Neodent Osseointegrated Implant) will be used to anchor the prosthesis. For M4 the implants will be perpendicularly positioned at the anterior region (M4S) in the canine fossa or at 45 degress to distal inclination (M4I). For M6, one additional implant will be placed bilaterally and perpendicular with the tuberosity of the maxillae (M6S) or at 45 degrees to mesial inclination (M6I). The implants will be splinted with a titanium bar in all models. The software Abaqus (Smartech) will determine the stress fields. The bone/implant interface will have two conditions: perfect contact and partially contact by using contact elements with frictional coefficient of 0.3. The nodes will be fixed in the 3 axes. Two loadings will be applied (150N): L1 - axially, at the region of first molar and L2 - obliquely (45 degrees) in the buccal-lingual direction at the same region. RESULTS: The values of maximum and minimum principal stress (Smax), shear stress (Sshear) and maximum and minimum elastic deformation (Smax) will be obtained for the bone-implant interface in each simulated situation to perform a descriptive statistical analysis. (AU)