Dental pulp stem cell-derived intracellular vesicles prevent orthodontic relapse by inhibiting PI3K/Akt/NF-κB-mediated osteoclast activity

• DPSC-IV promotes osteoblast differentiation and inhibits osteoclast differentiation, thereby preventing orthodontic relapse. • Subgingival injection of DPSC-IV during retention significantly reduces relapse distance and relapse rate in rats. • The anti-relapse effect is mediated by the PI3K/Akt/NF-κB signaling pathway, which can be reversed by IGF-1. • DPSC-IV offers a novel, cell-free therapeutic strategy for maintaining long-term orthodontic stability.