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Fracture of Ceramic/Ceramic/Polymer Trilayers for Biomechanical Applications



Y N. Deng, P Miranda, Antonia Pajares, Brian R. Lawn


Fracture damage in trilayers consisting of outer and inner brittle layers bonded to a compliant (polycarbonate) substrate and subjected to concentrated surface loading is analyzed. The principal mode of fracture is radial cracking at the undersurface of the inner (core) layer, even in the strongest of core ceramics other damage modes, including radial cracking in the outer (veneer) layer, are less invasive in these all-brittle coating systems. Tests on simple trilayer structures fabricated from glasses, sapphire and dental ceramics are used to examine the dependence of the critical load for radial fracture in terms of relative outer/inner layer thickness and modulus, and inner layer strength. An explicit relation for the critical load, based on a flexing plate model in which theouter/inner bilayer is reduced to an equivalent monolithic coating with effective composite modulus, is used to examine these dependencies. The theoretical relation describes all the major trends in the critical load data over a broad range of variables, thus providing a sound basis for trilayer design. Relevance of the analysis to dental crowns and other biomechanical applications is a central theme of the study.
Journal of Biomedical Materials Research Part A
No. 3


brittle coatings, cracking, critical loads, dental crowns, trilayers


Deng, Y. , Miranda, P. , Pajares, A. and Lawn, B. (2003), Fracture of Ceramic/Ceramic/Polymer Trilayers for Biomechanical Applications, Journal of Biomedical Materials Research Part A (Accessed June 13, 2024)


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Created November 30, 2003, Updated October 12, 2021