Biomechanical analysis of implant-supported prosthesis varying the type connection, the retention system, restorative material, type and level of bone tissue. Study by three-dimensional finite element method.

Abstract

This project aim to analyze the stress on implant-supported fixed prostheses varying connection type, and retention system, material of crown, type bone and bone tissue level and loading by 3D finite element method. Sixty-four three-dimensional models will be simulated with the assistance of CAD softwares Rhinoceros 3D 4.0 (NURBS Modeling for Windows, USA) and SolidWorks 2011 (SolidWorks Corp, USA). The bone block will be obtained by use of InVesalius (CTI, São Paulo, Brasil). Each model will represent a section of bone of the maxillary posterior region in the form of a type IV bone block (cortical and trabecular) (normal and osteoporotic bone tissue), varying the bone resorption level (bone at implant neck level; with loss of 1.5 mm; with loss of 3.0 mm; and with loss of 4.5 mm), with the presence of an implant with 4.0 mm of diameter and 10 mm length, varying the connection type (external hexagon, and Morse taper). All prostheses will be metal-ceramic and metal free crown with different retention system (cement- and screw-retained). The three-dimensional models will be exported to the pre- and post-processing program FEMAP v.11.2 (Siemens Product Lifecycle Management Software Inc. USA) for mesh generation and configuration of load of 200N axial and 100N oblique (45º) applied at internal side of each cusp, simulating a functional loading. The analysis will be performad by NEiNastran 11 (Noran Engineering, Inc., EUA). The results will be displayed using von Mises maps and displacement to evaluate the stress on the implants/components, and maximum principal stress and microstrain in the bone tissue in each proposed model in the software FEMAP 11.2. Statistical analysis will be performed with values obtained through specific points of the cortical bone, implants and screws. In addition, it will be held parallel to the finite element analysis, a systematic review, addressing the variables of types connection in relation to marginal bone loss verifying that the bone tissue level influence the longevity of the treatment. the second systematic review will to evaluate the influence of osteoporotic bone to implant survival rate and marginal bone loss; and the third systematic review will evaluate the influence of the restorative material in prosthetic implants (metal-ceramic and metal free) compared complication rates (biological and / or mechanical), marginal bone loss and implant survival.