Mechanically Reinforced Artificial Enamel by Mg²⁺-Induced Amorphous Intergranular Phases

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Nanotechnology

Background:

• Amorphous intergranular phases in natural tooth enamel enhance adhesion and mechanical performance.
• Understanding these phases is crucial for developing advanced biomimetic materials.

Purpose of the Study:

• To synthesize room-temperature amorphous intergranular phase-enhanced fluorapatite arrays (FAP-M) controlled by Mg2+.
• To investigate the role of Mg2+ in the formation and function of these intergranular phases.
• To evaluate the mechanical properties of the synthesized artificial enamel.

Main Methods:

• Controlled synthesis of Mg2+-enhanced fluorapatite arrays (FAP-M) at room temperature.
• Atom probe tomography (APT) for detailed microstructural and chemical analysis.
• Mechanical testing to determine hardness and Young's modulus.

Main Results:

• Mg2+ enrichment at grain boundaries during FAP-M assembly.
• Formation of Mg-rich amorphous calcium phosphate (Mg-ACP) intergranular phases.
• Mg2+ segregation induced chemical gradients, promoting nanocrystalline realignment and reinforcing the structure.
• FAP-M exhibited significantly improved mechanical properties: hardness (2.90 ± 0.13 GPa) and Young's modulus (67.9 ± 3.4 GPa).

Conclusions:

• Mg2+-controlled amorphous intergranular phases act as a 'glue' to reinforce fluorapatite arrays.
• The synthesized FAP-M artificial enamel demonstrates superior mechanical performance compared to Mg2+-free FAP arrays.
• This study provides insights into biomimetic strategies for creating high-performance enamel-like materials.