Article

Three-dimensional finite element modeling from CT images of tooth and its validation

Division of Biomaterials, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita, Kitakyushu 803-8580, Japan.
Dental Materials Journal (Impact Factor: 0.97). 04/2009; 28(2):219-26. DOI: 10.4012/dmj.28.219
Source: PubMed

ABSTRACT

The aim of this study was to develop a three-dimensional (3D) finite element (FE) model of a sound extracted human second premolar from micro-CT data using commercially available software tools. A detailed 3D FE model of the tooth could be constructed and was experimentally validated by comparing strains calculated in the FE model with strain gauge measurement of the tooth under loading. The regression coefficient and its standard error in the regression analysis between strains calculated by the FE model and measured with strain gauge measurement were 0.82 and 0.06, respectively, and the correlation coefficient was found to be highly significant. These results suggested that an FE model reconstructed from micro-CT data could be used as a valid model to estimate the actual strains with acceptable accuracy.

Download full-text

Full-text

Available from: Kiyoshi Tajima
  • Source
    • "However, it is difficult to systemize the data, as tooth dimensions and experimental conditions are not usually included. From a theoretical standpoint, many studies have been made of stress distributions in loaded teeth using conventional finite element modeling (FEM) codes [24] [25] [26] [27] [28] [29] [30] [31] [32], but these can say virtually nothing about how stable fractures evolve. They certainly cannot account for any stages of crack arrest in the enamel and subsequent penetration into the dentin interior [13]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A model for the splitting of teeth from wedge loading of molar cusps from a round indenting object is presented. The model is developed in two parts: first, a simple 2D fracture mechanics configuration with the wedged tooth simulated by a compact tension specimen; second, a full 3D numerical analysis using extended finite element modeling (XFEM) with an embedded crack. The result is an explicit equation for splitting load in terms of indenter radius and key tooth dimensions. Fracture experiments on extracted human molars loaded axially with metal spheres are used to quantify the splitting forces and thence to validate the model. The XFEM calculations enable the complex crack propagation, initially in the enamel coat and subsequently in the interior dentin, to be followed incrementally with increasing load. The fracture evolution is shown to be stable prior to failure, so that dentin toughness, not strength, is the controlling material parameter. Critical conditions under which tooth splitting in biological and dental settings are likely to be met, however rare, are considered. Copyright © 2015. Published by Elsevier Ltd.
    Full-text · Article · Jan 2015 · Acta Biomaterialia
    • "Dessa forma a disponibilidade de modelos da mandíbula, tanto dentada quanto desdentada, pode facilitar diversas pesquisas na área, além de favorecer possíveis análises comparativas que utilizam o mesmo modelo geométrico. Os exames de micro tomografias, devido à sua alta precisão, seriam teoricamente o melhor método para obtenç ão de modelos anatômicos geometricamente precisos [7] [8] [9] [10], entretanto, devido ao alto custo, alta exposiç ão à radiaç ão e limitaç ão quanto ao tamanho da zona analisada, esses são contraindicados para utilizaç ão em seres humanos vivos. Aumento na dose de radiaç ão está diretamente relacionado à qualidade da imagem obtida, com melhora no contraste e diminuiç ão de artefatos [11] [12] e micro tomógrafos utilizam níveis de radiaç ão muito maiores que o aceitável para aplicaç ão em pacientes vivos. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Detailed geometric models of a mandible can improve the accuracy of computer simulations. However, cost, time and qualified labor available for their construction may hinder or delay the task. The purpose of this article is to describe a technique for reconstructing a mandible with and without teeth from clinical CT scans of low resolution. The method allows modeling geometric details usually difficult to reconstruct with these scans, such as the periodontal ligament. The models of a toothless and toothed mandible resulting from the process are available online for non‐commercial use. The models can be used in various fields such as orthodontics, implantology, orthopedics and traumatology as presented or as a basis for simulations.
    No preview · Article · Dec 2014 · Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería
  • Source
    • "Twodimensional or three-dimensional approaches have been used for modeling purposes [6]. Two-dimensional models are criticized as they result in oversimplified geometries of complex structures that in turn may compromise the reliability of predicting the mechanical behavior of the object [7] [14] [15]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The effect of preparation design and the physical properties of the interface lute on the restored machined ceramic crown-tooth complex are poorly understood. The aim of this work was to determine, by means of three-dimensional finite element analysis (3D FEA) the effect of the tooth preparation design and the elastic modulus of the cement on the stress state of the cemented machined ceramic crown-tooth complex. The three-dimensional structure of human premolar teeth, restored with adhesively cemented machined ceramic crowns, was digitized with a micro-CT scanner. An accurate, high resolution, digital replica model of a restored tooth was created. Two preparation designs, with different occlusal morphologies, were modeled with cements of 3 different elastic moduli. Interactive medical image processing software (mimics and professional CAD modeling software) was used to create sophisticated digital models that included the supporting structures; periodontal ligament and alveolar bone. The generated models were imported into an FEA software program (hypermesh version 10.0, Altair Engineering Inc.) with all degrees of freedom constrained at the outer surface of the supporting cortical bone of the crown-tooth complex. Five different elastic moduli values were given to the adhesive cement interface 1.8GPa, 4GPa, 8GPa, 18.3GPa and 40GPa; the four lower values are representative of currently used cementing lutes and 40GPa is set as an extreme high value. The stress distribution under simulated applied loads was determined. The preparation design demonstrated an effect on the stress state of the restored tooth system. The cement elastic modulus affected the stress state in the cement and dentin structures but not in the crown, the pulp, the periodontal ligament or the cancellous and cortical bone. The results of this study suggest that both the choice of the preparation design and the cement elastic modulus can affect the stress state within the restored crown-tooth complex.
    Full-text · Article · May 2013 · Dental materials: official publication of the Academy of Dental Materials
Show more