Alveolar ridge preservation with lyophilized microspheres of human dental pulp stem cells following 3D dynamic osteogenic induction.

The clinical use of bone graft materials for alveolar ridge preservation following tooth extraction has become a standard procedure to facilitate subsequent implant restoration and prosthetic rehabilitation. However, the therapeutic efficacy of these materials is substantially limited by their bio-inertness, lack of cellular activity, and unpredictable resorption rates. The development of bioactive osteogenic materials capable of host integration and active promotion of bone regeneration would represent a significant advancement over current clinical protocols. To address this challenge, our research has focused on developing bioactive biomaterials using human dental pulp stem cells (hDPSCs). This study proposes a novel strategy for alveolar ridge repair utilizing lyophilized hDPSC microspheres preconditioned through a three-dimensional (3D) dynamic osteogenic induction system. We cultured hDPSCs into 3D microspheres and subjected them to osteogenic induction within our established dynamic culture system, followed by lyophilization to prepare "off-the-shelf" osteogenic tissues. The resulting lyophilized microsphere constructs were implanted into fresh extraction sockets of SD rats and New Zealand white rabbits and evaluated over 4 weeks. Comparative analysis demonstrated that the lyophilized microsphere group exhibited significantly enhanced alveolar bone preservation, superior new bone formation, and improved bone microarchitecture compared to both control groups and traditional artificial bone powder groups. This preclinical study validates the potential of lyophilized hDPSC microspheres as an efficient and clinically promising bioactive material for post-extraction alveolar ridge reconstruction.