Tooth enamel’s unusual combination of properties is a product of its hierarchical architecture, a complex structure made up of mostly hydroxyapatite nanowires interconnected by an amorphous intergranular phase (AIP) consisting of magnesium-substituted amorphous calcium phosphate.
However, accurately replicating this type of hierarchical organization in a scalable abiotic composite has remained a challenge.
To overcome this, researchers present an engineered enamel that contains the essential hierarchical structure at multiple scales.
The artificial tooth enamel (ATE) was produced using AIP-coated hydroxyapatite nanowires, which were aligned using dual-directional freezing in the presence of polyvinyl alcohol. This allowed the engineered structures to have an atomic, nanoscale, and microscale organization like natural enamel.
In a series of tests, researchers demonstrated that the ATE nanocomposite simultaneously exhibited high stiffness, hardness, strength, viscoelasticity, and toughness, exceeding both the properties of enamel and previously manufactured materials.