Numerical simulation of the fracture process in ceramic FPD frameworks caused by oblique loading

Abstract

Finite element analysisFixed partial denture Fracture process Numerical simulationOblique loading a b s t r a c t Using a newly developed three-dimensional (3D) numerical modeling code, an analysis was performed of the fracture behavior in a three-unit ceramic-based fixed partial denture (FPD) framework subjected to oblique loading. All the materials in the study were treated heterogeneously; Weibull's distribution law was applied to the description of the heterogeneity. The Mohr-Coulomb failure criterion with tensile strength cut-off was utilized in judging whether the material was in an elastic or failed state. The simulated loading area was placed either on the buccal or the lingual cusp of a premolar-shaped pontic with the loading direction at 301, 451, 601, 751 or 901 angles to the occlusal surface. The stress distribution, fracture initiation and propagation in the framework during the loading and fracture process were analyzed. This numerical simulation allowed the cause of the framework fracture to be identified as tensile stress failure. The decisive fracture was initiated in the gingival embrasure of the pontic, regardless of whether the buccal or lingual cusp of the pontic was loaded. The stress distribution and fracture propagation process of the framework could be followed step by step from beginning to end. The bearing capacity and the rigidity of the framework vary with the loading position and direction. The framework loaded with 901 towards the occlusal surface has the highest bearing capacity and the greatest rigidity. The framework loaded with 301 towards the occlusal surface has the least rigidity indicating that oblique loading has a major impact on the fracture of ceramic frameworks.& 2015 Elsevier Ltd. All rights reserved. IntroductionCeramics are among the most inert biomaterials known. Their advantages include high biocompatibility (Depprich et al., 2008), good esthetic appearance (Ghazal et al., 2008), low solubility and low thermal conductivity (Chai et al., 2007). Among the crucial problems for ceramics, however, are low fracture resistance and brittleness and, consequently, no or little apparent plastic deformation can occur before fracture (Munz and Fett, 1999 j o u r n a l o f t h e m e c h a n i c a l b e h a v i o r o f b i o m e d i c a l m a t e r i a l s 5 0 ( 2 0 1 5 ) 2 0 6 -2 1 4

Biomechanical Behavior of Tooth-Supported Fixed Partial Prostheses Components with Two Different Infrastructures: Metal and Polyether Ether Ketone (Peek).

“…This small proportion of results suggest a long lifespan of both treatments, although longer in the case of the metal-ceramic model. As observed, oblique strengths produced larger stresses than the axial ones, corroborating other studies [26,27]. This represents an important impact on the fracture of structures.…”

Effects of two grading techniques of zirconia material on the fatigue limit of full-contour 3-unit fixed dental prostheses

“…Thus, we selected the worst scenario, according Kou et al [52], with samples positioned 30° under loading on the buccal cusps. Furthermore, crown-shaped test specimens cemented on preparations of tooth-like material may bring the test conditions even closer to the clinical situation [53].…”

Estudo in Vitro Da Influência Da Vibração Sônica Na Proliferação, Viabilidade E Expressão De Il-1 E Il-17 Em Células Osteoblásticas

“…Na carga axial, apresentou o valor de 3,67 MPa e concentração na região de término (próximo ao pôntico), enquanto que, na carga oblíqua, chegou a 19,58 MPa e concentrou-se na porção lingual das raízes. As forças oblíquas produzem maiores tensões na dentina remanescente do que as forças verticais (Modi et al, 2015) e a fratura é iniciada na região de pôntico, independentemente do carregamento da cúspide vestibular ou lingual (Kou et al, 2015).…”