Related Experiment Video
Updated: Jun 18, 2026

In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint
Published on: March 7, 2014
Synchrotron X-ray diffraction study of load partitioning during elastic deformation of bovine dentin
A C Deymier-Black1, J D Almer, S R Stock
1Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA. alixdeymier2010@u.northwestern.edu
Abstract:
The elastic properties of dentin, a biological composite consisting of stiff hydroxyapatite (HAP) nano-platelets within a compliant collagen matrix, are determined by the volume fraction of these two phases and the load transfer between them. We have measured the elastic strains in situ within the HAP phase of bovine dentine by high energy X-ray diffraction for a series of static compressive stresses at ambient temperature. The apparent HAP elastic modulus (ratio of applied stress to elastic HAP strain) was found to be 18+/-2GPa. This value is significantly lower than the value of 44GPa predicted by the lower bound load transfer Voigt model, using HAP and collagen volume fractions determined by thermo-gravimetric analysis. This discrepancy is explained by (i) a reduction in the intrinsic Young's modulus of the nano-size HAP platelets due to the high fraction of interfacial volume and (ii) an increase in local stresses due to stress concentration around the dentin tubules.
Related Concept Videos
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
Normal Strain under Axial Loading
X-ray Diffraction of Biological Samples
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
Residual Stresses in Bending
Elastic Strain Energy for Shearing Stresses
Deformation of Member under Multiple Loadings
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...

