Development of a three‐dimensional finite element model of a human mandible containing endosseous dental implants. II. Variables affecting the predictive behavior of a finite element model of a human mandible

Abstract

The purpose of this study was to propose a systematic approach to validate a finite element model (FEM) of the human mandible and to investigate the effects of changing the geometry and orthotropic material properties on the FEM predictions. Thirty-eight variables affecting the material properties, boundary conditions, and the geometry of a FEM of a human mandible, including two dental implants, were systematically changed, creating a number of FEMs of the mandible. The effects of the variations were quantified as differences in the principal strain magnitudes modeled by the original FEM (gold standard), prior to the sensitivity analyses, and those generated by the changed FEMs. The material properties that had the biggest impact on the predicted cortical principal strain were the shear moduli (up to 31% in difference from the unchanged state), and the absence of cancellous bone (up to 34%). Alterations to the geometry of the mandibular cross section, such as an increase in corpus dimensions, had the greatest effect on principal strain magnitudes (up to 16%). Changes in the cortical thickness in relation to the width of the corpus section modified strain more than alterations to the corpus depth (14% and 5%, respectively). The relatively small difference (up to 13.5%) between the predicted and measured interimplant distances indicates the accuracy of the FEM. Changes in geometry and orthotropic material properties could induce significant changes in strain patterns. These values must therefore be chosen with care when using finite element techniques for predicting stresses, strains, and displacements.

FEM and VonMises analyses of different dental implant shapes for masticatory loading distribution

“…The leaders represented the five elements of the system under investigation (fixture and abutment screw connection for the implant; cancellous and cortical bone). Taking into consideration the limitations of the materials, we calculated the percentages of all elements survival (17,(20)(21)(22). It was considered as the yield strength of the titanium alloy grade 4 a value of 550 MPa.…”

Dental implant induced bone remodeling and associated algorithms

“…Four different types of material properties have been adopted in FE modeling: isotropic, transversely isotropic (O'Mahony et al, 2001;Petrie and Williams, 2005), orthotropic and anisotropic (Al-Sukhun et al, 2007;Huang et al, 2007). An isotropic material means that the material properties are identical in all directions, thus only two independent material constants (Young's modulus E and Poisson's ratio ν) are required for a linear FEA.…”

Tooth Eruption Results from Bone Remodelling Driven by Bite Forces Sensed by Soft Tissue Dental Follicles: A Finite Element Analysis

“…Dentine, pulp, enamel, periodontal ligament, dental follicle, cortical bone and cancellous bone were assigned relevant mechanical properties as indicated in Table 1, according to values established in the literature [53], [63]–[66]. Please note that although the mechanical properties of bone do vary according to the direction of force applied, these differences are nonetheless fairly small in all three directions [67], [68] and to a considerable extent lead to very close agreement between experimental and numerical results [64], [69]. For this reason, use of linear isotropic elastic properties seems justifiable in anatomical modelling under physiological loading [70].…”