Three-dimensional Finite Element Analysis of Stress Distribution in Composite Resin Cores with Fiber Posts of Varying Diameters

Abstract

Using three-dimensional finite element analysis (3D-FEA), stress distributions in the remaining radicular tooth structure were investigated under the condition of varying diameters of fiber post for fiber post-reinforced composite resin cores (fiber post and core) in maxillary central incisors. Four 3D-FEA models were constructed: (1) fiber post (φ1.2, φ1.4, and φ1.6 mm) and composite resin core; and (2) gold-cast post and core. Maximum stresses in the tooth structure for fiber post and core were higher than that for gold-cast post and core. In the former models, stresses in the tooth structure as well as in the composite resin were slightly reduced with increase in fiber post diameter. These results thus suggested that to reduce stress in the remaining radicular tooth with a large coronal defect, it is recommended to accompany a composite resin core with a fiber post of a large diameter.

Biomechanical Models of Endodontic Restorations

“…The elastic modulus is lower for small strains and increases suddenly for strains greater than near 20%-30% in both tension and compression (Pini et al, 2002). However, some models of the ligament in endodontic simulation simplify this characteristic using an isotropic, linear and perfectly elastic material (Garbin et al, 2010;Mezzomo et al, 2011;Okamoto et al, 2008). This simplification avoids the iterative procedure associated to a non-linear model that entails an important increase in computation time.…”

“…4 shows a sagittal section of a mesh using tetrahedral elements for a restored incisor, generated by the authors using the Pro/Engineer FEM mesher. Some works, however, have used hexahedral elements (Ferrari et al, 2008;Okamoto et al, 2008;Schmitter et al, 2010;Zarone et al, 2006), which provide models with good results using fewer degrees of freedom, but at the cost of a more difficult mesh generation. In some models, elements with quadratic interpolation, i.e.…”

“…Three-dimensional models have been used extensively for simulating endodontic treatment since the beginning of the century Ausiello et al, 2002;BarjauEscribano et al, 2006;Boschian Pest et al, 2006;Genovese et al, 2005;Lanza et al, 2005). In recent years some of the most complete three-dimensional models ever developed for studying the biomechanics of endodontic restorations have been reported (Ferrari et al, 2008;Garbin et al, 2010;Gonzalez-Lluch et al, 2009b;Maceri et al, 2009;Mezzomo et al, 2011;Okamoto et al, 2008;Schmitter et al, 2010). In these three-dimensional models, tetrahedral or hexahedral finite elements are used.…”

“…However, some works did not include the ligament (Yaman et al, 1998;Zarone et al, 2006), despite it has been reported that stress distribution is affected to an important degree by this omission (Davy et al, 1981) or even by a geometrically simplified representation (Toms & Eberhardt, 2003). When cement layers are considered in the biomechanical model, they are usually represented with a constant small thickness Maceri et al, 2009;Okamoto et al, 2008;Schmitter et al, 2010). However, some works simplify the model by obviating the cement in the interface between the core and the crown (Gonzalez-Lluch et al, 2009b;Lanza et al, 2005) or even in the interface between the post and the root (Adanir & Belli, 2007;Hsu et al, 2009).…”

“…Table 2. Range of values for elastic properties for dental materials used in some FE models (Ferrari et al, 2008;Ferrari et al, 2008;Garbin et al, 2010;Gonzalez-Lluch et al, 2009b;Hsu et al, 2009;Maceri et al, 2009;Mezzomo et al, 2011;Okamoto et al, 2008;Schmitter et al, 2010;Suzuki et al, 2008;Toparli, 2003).…”