title: Size dependent elastic modulus and mechanical resilience of dental enamel.
abstract: Human tooth enamel exhibits a unique microstructure able to sustain repeated mechanical loading during dental function. Although notable advances have been made towards understanding the mechanical characteristics of enamel, challenges remain in the testing and interpretation of its mechanical properties. For example, enamel was often tested under dry conditions, significantly different from its native environment. In addition, constant load, rather than indentation depth, has been used when mapping the mechanical properties of enamel. In this work, tooth specimens are prepared under hydrated conditions and their stiffnesses are measured by depth control across the thickness of enamel. Crystal arrangement is postulated, among other factors, to be responsible for the size dependent indentation modulus of enamel. Supported by a simple structure model, effective crystal orientation angle is calculated and found to facilitate shear sliding in enamel under mechanical contact. In doing so, the stress build-up is eased and structural integrity is maintained.
authors: School of Engineering, Edith Cowan University, Perth, WA, Australia; Perth Institute of Business and Technology, Perth, WA, Australia.
authors: Simona
authors: S
authors: O'Brien
authors: Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA, Australia.
authors: Jeremy
authors: J
authors: Shaw
authors: School of Engineering, Edith Cowan University, Perth, WA, Australia.
authors: Xiaoli
authors: X
authors: Zhao
authors: School of Dentistry, The University of Western Australia, Perth, WA, Australia.
authors: Paul V
authors: PV
authors: Abbott
authors: School of Materials Science and Engineering, University of New South Wales, Sydney, NSW, Australia.
authors: Paul
authors: P
authors: Munroe
authors: Department of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People׳s Republic of China; School of Mechanical and Electrical Engineering, Wuhan Institute of Technology, Wuhan 430073, People׳s Republic of China.
authors: Jiang
authors: J
authors: Xu
authors: School of Engineering, Edith Cowan University, Perth, WA, Australia.
authors: Daryoush
authors: D
authors: Habibi
authors: School of Engineering, Edith Cowan University, Perth, WA, Australia; School of Mechanical Engineering, University of Adelaide, Adelaide, SA, Australia; School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300387, People׳s Republic of China. Electronic address: zonghan.xie@adelaide.edu.au.
authors: Zonghan
authors: Z
authors: Xie
mesh_terms: D000328:Adult; D003743:Dental Enamel / Q000737:chemistry* / Q000502:physiology; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D008964:Molar, Third / Q000502:physiology*; D016474:Weight-Bearing; D055815:Young Adult
keywords: Deformation; Finite element analysis; Nanoindentation; Tooth enamel; Young׳s modulus