Micromechanical characterization of prismless enamel in the tuatara, Sphenodon punctatus

作者：Yilmaz Ezgi D; Bechtle Sabine; Oezcoban Hueseyin; Kieser Jules A; Swain Michael V; Schneider Gerold A^*

来源：Journal of the Mechanical Behavior of Biomedical Materials, 2014, 39: 210-217.

DOI：10.1016/j.jmbbm.2014.07.024

• Biological materials
• Prism less enamel
• Strength
• Fracture toughness

Dental enamel - a naturally occurring biocomposite of mineral and protein - has evolved from a simple prismless to an advanced prismatic structure over millions of years. Exploring the mechanical function of its structural features with differing characteristics is of great importance for evolutionary developmental studies as well as for material scientists seeking to model the mechanical performance of biological materials. In this study, mechanical properties of prismless tuatara Sphenodon punctatus enamel were characterized. Using microcantilever bending samples the fracture strength and elastic modulus were found to be 640 +/- 87 MPa and 42 +/- 6 GPa, respectively in the orientation parallel to the crystallite long axis, which decreased in the orthogonal direction. The intrinsic fracture toughness of tuatara enamel ranged from 0.21 MPa m(1/2) and 0.32 MPa m(1/2). These values correspond to the lower limit of the range of values observed in prismatic enamel at the hierarchical level 1.

• 出版日期2014-11