TY - JOUR

T1 - Unraveling the orientation-dependent mechanics of dental enamel in the red-necked wallaby

AU - Wilmers, Jana

AU - Wurmshuber, Michael

AU - Gescher, Christoph

AU - Graupp, Celine Michele

AU - Kiener, Daniel

AU - Bargmann, Swantje

N1 - Publisher Copyright: © 2024 The Author(s)

PY - 2024/9/1

Y1 - 2024/9/1

N2 - Dental enamels of different species exhibit a wide variety of microstructural patterns that are attractive to mimic in bioinspired composites to simultaneously achieve high stiffness and superior toughness. Non-human enamel types, however, have not yet received the deserved attention and their mechanical behaviour is largely unknown. Using nanoindentation tests and finite element modelling, we investigate the mechanical behaviour of Macropus rufogriseus enamel, revealing a dominating influence of the microstructure on the effective mechanical behaviour and allowing insight into structural dependencies. We find a shallow gradient in stiffness and low degree of anisotropy over the enamel thickness that is attributed to the orientation and size of microstructural features. Most notably, M. rufogriseus's modified radial enamel has a far simpler structural pattern than other species’, but achieves great property amplification. It is therefore a very promising template for biomimetic design. Statement of significance: The diversity of dental enamel structures in different species is well documented, but the mechanical behaviour of non-human enamel types is largely unknown. In this work, we investigate the microstructure and structure-dependent mechanical properties of marsupial enamel by nanoindentation and finite element simulations. Combining these methods gives valuable insights into the performance of modified radial enamel structures. Their stiffness and toughness stems from a unique structural design that is far less complex than well-studied human enamel types, which makes it a uniquely suitable template for biomimetic design.

AB - Dental enamels of different species exhibit a wide variety of microstructural patterns that are attractive to mimic in bioinspired composites to simultaneously achieve high stiffness and superior toughness. Non-human enamel types, however, have not yet received the deserved attention and their mechanical behaviour is largely unknown. Using nanoindentation tests and finite element modelling, we investigate the mechanical behaviour of Macropus rufogriseus enamel, revealing a dominating influence of the microstructure on the effective mechanical behaviour and allowing insight into structural dependencies. We find a shallow gradient in stiffness and low degree of anisotropy over the enamel thickness that is attributed to the orientation and size of microstructural features. Most notably, M. rufogriseus's modified radial enamel has a far simpler structural pattern than other species’, but achieves great property amplification. It is therefore a very promising template for biomimetic design. Statement of significance: The diversity of dental enamel structures in different species is well documented, but the mechanical behaviour of non-human enamel types is largely unknown. In this work, we investigate the microstructure and structure-dependent mechanical properties of marsupial enamel by nanoindentation and finite element simulations. Combining these methods gives valuable insights into the performance of modified radial enamel structures. Their stiffness and toughness stems from a unique structural design that is far less complex than well-studied human enamel types, which makes it a uniquely suitable template for biomimetic design.

KW - Biomechanics

KW - Finite element simulations

KW - Hierarchical structure

KW - Micromechanics

KW - Microstructure

KW - Nanoindentation

UR - http://www.scopus.com/inward/record.url?scp=85198570199&partnerID=8YFLogxK

U2 - 10.1016/j.actbio.2024.07.004

DO - 10.1016/j.actbio.2024.07.004

M3 - Article

C2 - 38992410

AN - SCOPUS:85198570199

VL - 185.2024

SP - 254

EP - 265

JO - Acta biomaterialia

JF - Acta biomaterialia

SN - 1742-7061

IS - 1 September

ER -