Re-Mineralization By Polyelectrolyte Nanocomposite For Effective Against Dentin Hypersensitivity.

Introduction: Dentin hypersensitivity (DH) causes considerable discomfort in many patients due to its characteristic symptoms, which primarily arise from exposed dentinal tubules (DTs). DTs also serve as a pathway for bacterial invasion. Therefore, a treatment that both effectively occludes DTs and prevents caries is needed. Methods: Polyaspartic acid (Pasp) and carboxymethyl chitosan (CMC) were combined with amorphous calcium phosphate (ACP) to develop PCA. PCA was compared with three polyelectrolyte complexes (PA, CA, PC). Recombinant collagen models assessed the mineralization-promoting effect of PCA, whereas DH models evaluated its ability to occlude DTs. The sealing performance and surface hardness of PCA-treated dentin discs were assessed by airtightness and hardness tests. Antibacterial effects were analyzed using live-dead staining, bacterial adherence assays, and colony-forming unit (CFU) counts. Biocompatibility was evaluated by live-dead cell staining, CCK-8 assays, and hemolysis tests. Results: PCA contains ACP clusters approximately 2 nm in diameter and achieves effective intrafibrillar mineralization within 5 days. PCA completely covers the collagen fibers on the dentin surface and occludes the DTs. The remineralized dentin demonstrates excellent resistance to friction and acid exposure. PCA treatment significantly restores the airtightness and mechanical strength of demineralized dentin. Moreover, PCA exhibits strong antibacterial activity against Streptococcus mutans ( Conclusion: This study demonstrates the dual function of PCA in DH management and caries prevention by occluding DTs and providing antibacterial protection, supporting its potential for clinical application.