Dental tissue repair stimulated by complex amorphous calcium phosphate supraparticles

Dentin hypersensitivity (DH) is caused by various external stimuli through exposed dentinal tubules (DTs). Amorphous calcium phosphate (ACP)-based biomineralization strategy exhibits promising potential in structural biomimicry and various biomedical applications. However, ACP is unstable and prone to spontaneous crystallization, and it requires a continuous supply of mineral ions to support further biomineralization. Developing a stable ACP complex with the ability to sustain release mineral ions may represent a promising strategy for DH treatment via occluding DTs.

This study aims to construct novel biocompatible complex mesoporous bioactive glass@ACP (MBG@ACP) supraparticles with enhanced biomineralization capability to occlude DTs for treating DH.

MBG was synthesized via the sol-gel method, followed by amine functionalization with 3-aminopropyltriethoxysilane onto its pore surfaces. Then negative polyacrylic acid was adsorbed through amino-carboxyl group interactions, which subsequently induced ACP precipitation within the mesoporous channels to form complex MBG@ACP supraparticles.

MBG@ACP supraparticles showed superior effects in stimulating apatite formation with a depth of DTs occlusion over 30 μm. Both the acid and abrasive challenge tests demonstrated that the biomineralized layer was well preserved and firmly bonded to the tooth surface. The in vivo tests demonstrated that MBG@ACP supraparticles could completely occlude the exposed DTs by the dense mineralization layer only after three days' normal diet.

MBG@ACP supraparticles may offer a simple and efficient therapeutic strategy for treating DH, expanding the applications of MBG and ACP in biomedical fields.