Design of functionally graded dental multilayers

• Published in: Fatigue & fracture of engineering materials & structures 2011-11, Vol.34 (11), p.887-897
• Main Authors: RAHBAR, N., SOBOYEJO, W. O.
• Format: Article
• Language: English
• Subjects: Applied sciences; Dental care; Design engineering; Exact sciences and technology; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1111/j.1460-2695.2011.01581.x

ABSTRACT This paper presents the results of a computational and experimental effort to develop crack‐resistant dental multilayers that are inspired by the functionally graded dento‐enamel‐junction (DEJ) structure that occurs between dentin and enamel in natural teeth. The complex structures of natural teeth and ceramic crowns are idealized using flat‐layered configurations. The potential effects of teeth‐on‐teeth contact are then modelled using finite element simulations of Hertzian contact. The resulting stress distributions are compared for a range of possible bioinspired, functionally graded architecture. The computed stress distributions show that the highest stress concentrations in the top ceramic layer of crown structures are reduced significantly by the use of bioinspired functionally graded architectures. The reduced stresses are experimentally shown to be associated with significant improvements (∼32%) in the pop‐in loads. The implications of the results are discussed for the design of bioinspired dental ceramic crown structures. The bioinspired functionally graded layers are also shown to promote improvements in the critical crack size.