title: Topological design of all-ceramic dental bridges for enhancing fracture resistance.
abstract: Layered all-ceramic systems have been increasingly adopted in major dental prostheses. However, ceramics are inherently brittle, and they often subject to premature failure under high occlusion forces especially in the posterior region. This study aimed to develop mechanically sound novel topological designs for all-ceramic dental bridges by minimizing the fracture incidence under given loading conditions. A bi-directional evolutionary structural optimization (BESO) technique is implemented within the extended finite element method (XFEM) framework. Extended finite element method allows modeling crack initiation and propagation inside all-ceramic restoration systems. Following this, BESO searches the optimum distribution of two different ceramic materials, namely porcelain and zirconia, for minimizing fracture incidence. A performance index, as per a ratio of peak tensile stress to material strength, is used as a design objective. In this study, the novel XFEM based BESO topology optimization significantly improved structural strength by minimizing performance index for suppressing fracture incidence in the structures. As expected, the fracture resistance and factor of safety of fixed partial dentures structure increased upon redistributing zirconia and porcelain in the optimal topological configuration. Dental CAD/CAM systems and the emerging 3D printing technology were commercially available to facilitate implementation of such a computational design, exhibiting considerable potential for clinical application in the future. Copyright © 2015 John Wiley & Sons, Ltd.
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Zhongpu
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Junning
authors.initials: J
authors.lastname: Chen
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Eric
authors.initials: E
authors.lastname: Li
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Discipline of Biomaterials, Faculty of Dentistry, The University of Sydney, Sydney, NSW, 2010, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Swain
authors.affiliation: School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
mesh_terms: D002516:Ceramics; D017076:Computer-Aided Design; D003776:Dental Porcelain; D003830:Denture, Partial, Fixed; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical
chemical_list: D003776:Dental Porcelain
keywords: XFEM; dental bridges; fracture resistance; layered ceramic; topology optimization