RESUMEN
The definition of an optimal elastic modulus for a post is controversial. This work hypothesized that the influence of the posts' elastic modulus on dentin stress concentration is dependent on the load direction. The objective was to evaluate, using finite element analysis, the maximum principal stress (sigma(max)) on the root, using posts with different elastic modulus submitted to different loading directions. Nine 3D models were built, representing the dentin root, gutta-percha, a conical post and the cortical bone. The softwares used were: MSC.PATRAN2005r2 (preprocessing) and MSC.Marc2005r2 (processing). Load of 100 N was applied, varying the directions (0 degrees, 45 degrees and 90 degrees) in relation to the post's long axis. The magnitude and direction of the sigma(max) were recorded. At the 45 degrees and 90 degrees loading, the highest values of sigma(max) were recorded for the lowest modulus posts, on the cervical region, with a direction that suggests debonding of the post. For the 0 degrees loading, the highest values of sigma(max) were recorded for higher modulus posts, on the apical region, and the circumferential direction suggests vertical root fracture. The hypothesis was accepted: the effect of the elastic modulus on the magnitude and direction of the sigma(max) generated on the root was dependent on the loading direction.
Asunto(s)
Cavidad Pulpar/fisiopatología , Técnica de Perno Muñón/instrumentación , Fracturas de los Dientes/etiología , Raíz del Diente/lesiones , Proceso Alveolar/fisiopatología , Simulación por Computador , Desconsolidación Dental , Dentina/fisiopatología , Módulo de Elasticidad , Análisis de Elementos Finitos , Gutapercha/química , Humanos , Imagenología Tridimensional/métodos , Incisivo/fisiopatología , Ensayo de Materiales , Modelos Biológicos , Materiales de Obturación del Conducto Radicular/química , Estrés Mecánico , Ápice del Diente/fisiopatología , Cuello del Diente/fisiopatología , Fracturas de los Dientes/fisiopatología , Raíz del Diente/fisiopatología , Alveolo Dental/fisiopatologíaRESUMEN
The purpose of this study was to compare the results of different hierarchical models in engineering analysis applied to dentistry with 2D and 3D models of a tooth and its supporting structures under 100 N occlusal loading at 45° and examine the reliability of simplified 2D models in dental research. Five models were built from computed-tomography scans: four 2D models with Plane Strain and Plane Stress State with linear triangular and quadratic quadrilateral elements and one 3D model. The finite element results indicated that the stress distribution was similar qualitatively in all models but the stress magnitude was quite different. It was concluded that 2D models are acceptable when investigating the biomechanical behavior of upper central incisor qualitatively. However, quantitative stress analysis is less reliable in 2D-finite element analysis, because 2D models overestimate the results and do not represent the complex anatomical configuration of dental structures. Therefore 3D finite element analyses of dental biomechanics cannot be simplified.
Asunto(s)
Análisis de Elementos Finitos , Incisivo/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , HumanosRESUMEN
Our aim was to document the benefits of three dimensional finite element model generations from computed tomography data as well as the realistic creation of all oral structures in a patient. The stresses resulting from the applied load in our study did not exceed the structure limitations, suggesting a clinically acceptable physiological condition.