Bone strength and residual compressive stress in apatite crystals

Area of Science:

• Biomaterials Science
• Composite Materials
• Nanomechanics

Background:

• Residual stresses are common in composite materials, developing during fabrication.
• Compressive residual stresses are observed in collagen fibrils during bone mineralization.
• These stresses are present in various bony materials, including dentin and bone.

Purpose of the Study:

• To review knowledge on residual stresses in bony nanocomposites.
• To use a composite model to explain the role of residual stresses in bone strength.

Main Methods:

• Literature review of residual stresses in bony materials.
• Analysis using a composite model.

Main Results:

• Compressive residual stresses up to 100 MPa can be released by damaging protein fibers via heat or irradiation.
• A composite model suggests these stresses are key to bone's enhanced strength.

Conclusions:

• Residual stresses, particularly compressive ones in collagen fibrils, are integral to bone's mechanical properties.
• Understanding and potentially manipulating these stresses could inform strategies for bone repair and enhancement.