title: Bio-inspired design of dental multilayers: experiments and model.
abstract: This paper combines experiments, simulations and analytical modeling that are inspired by the stress reductions associated with the functionally graded structures of the dentin-enamel-junctions (DEJs) in natural teeth. Unlike conventional crown structures in which ceramic crowns are bonded to the bottom layer with an adhesive layer, real teeth do not have a distinct "adhesive layer" between the enamel and the dentin layers. Instead, there is a graded transition from enamel to dentin within a approximately 10 to 100 microm thick regime that is called the Dentin Enamel Junction (DEJ). In this paper, a micro-scale, bio-inspired functionally graded structure is used to bond the top ceramic layer (zirconia) to a dentin-like ceramic-filled polymer substrate. The bio-inspired functionally graded material (FGM) is shown to exhibit higher critical loads over a wide range of loading rates. The measured critical loads are predicted using a rate dependent slow crack growth (RDEASCG) model. The implications of the results are then discussed for the design of bio-inspired dental multilayers.
authors.affiliation: Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University, Princeton, NJ 08544, United States.
authors.forename: Xinrui
authors.initials: X
authors.lastname: Niu
authors.forename: Nima
authors.initials: N
authors.lastname: Rahbar
authors.forename: Stephen
authors.initials: S
authors.lastname: Farias
authors.forename: Wole
authors.initials: W
authors.lastname: Soboyejo
mesh_terms: D001696:Biomechanical Phenomena; D040761:Biomimetic Materials / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin; D055119:Elastic Modulus; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D011108:Polymers / Q000737:chemistry; D014070:Tooth / Q000033:anatomy & histology* / Q000502:physiology*; D015040:Zirconium / Q000737:chemistry
chemical_list: D003764:Dental Materials; D011108:Polymers; D015040:Zirconium; C028541:zirconium oxide