Non-linear Viscoelastic Finite Element Analysis of the Effect of the Length of Glass Fiber Posts on the Biomechanical Behaviour of Directly Restored Incisors and Surrounding Alveolar Bone

Abstract

The study aimed at estimating the effect of insertion length of posts with composite restorations on stress and strain distributions in central incisors and surrounding bone. The typical, average geometries were generated in a FEA environment. Dentin was considered as an elastic orthotropic material, and periodontal ligament was coupled with nonlinear viscoelastic mechanical properties. The model was then validated with experimental data on displacement of incisors from published literature. Three post lengths were investigated in this study: root insertion of 5, 7, and 9 mm. For control, a sound incisor model was generated. Then, a tearing load of 50 N was applied to both sound tooth and simulation models. Post restorations did not seem to affect the strain distribution in bone when compared to the control. All simulated post restorations affected incisor biomechanics and reduced the root ' s deforming capability, while the composite crowns underwent a higher degree of deformation than the sound crown. No differences could be noticed in incisor stress and strain. As for the influence of post length, it was not shown to affect the biomechanics of restored teeth.

The mechanical properties of human dentin for 3-D finite element modeling – numerical and analytical evaluation

“…There are a few main mechanical parameters connected with the physical problems and qualities which can have a direct link to the obtained results, including dentin properties, which are usually assumed to be homogeneous, isotropic and linear elastic. [3][4][5][6][7] Expanding such a method into biomechanics requires a significant and continuous improvement of modeling techniques with respect to the individual anatomic and pathological characteristics of human tissues.…”

“…[1][2][3][4][5] The FEM enables the modeling of very complex structures (e.g. teeth) and gives an accurate description of the local strain and stress inside the non-homogenous material.…”

“…[3][4][5][6] Depending on the research topic, finite element (FE) models in macro-, meso-and microscales can be used. 3,[7][8][9] However, FE models of the biological structure are usually performed using a simplified approach. The employed method may play different roles depending on the model type, physics-related problems or the investigation's objectives.…”

Biomechanical Models of Endodontic Restorations

“…These first works were twodimensional and were conducted with programs developed by the researchers themselves. Later, the advances in computer resources and in commercial software for FEA extended the use of different commercial programs, allowing more accurate and predictive threedimensional models to be developed Barjau-Escribano et al, 2006;Boschian Pest et al, 2006;Ferrari et al, 2008;Genovese et al, 2005;Gonzalez-Lluch et al, 2009b;Maceri et al, 2009;Rodríguez-Cervantes et al, 2007;Sorrentino et al, 2007). The number of publications dealing with FE simulation in endodontics has increased exponentially in recent years.…”

“…Authors using two-dimensional data sometimes make use of appropriate algorithms to obtain a three-dimensional model (Maceri et al, 2007). With advances in CAD software and 3D scanning methods, most of the recent works obtain the external geometry of a real representative tooth or a plaster model using 3D digitising scanners (Ausiello et al, 2001;Ferrari et al, 2008;Ichim et al, 2006) and import it into a 3D CAD software application. The geometrical representation of the different components of the restoration is obtained later in CAD using Boolean algebra.…”