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

## TL;DR

This study explores using human dental pulp stem cells in a new way to improve alveolar ridge preservation after tooth extraction.

## Contribution

A novel bioactive material using lyophilized hDPSC microspheres preconditioned with 3D dynamic osteogenic induction is introduced.

## Key findings

- Lyophilized hDPSC microspheres showed enhanced alveolar bone preservation in preclinical models.
- The microspheres promoted superior new bone formation and improved bone microarchitecture.
- Results outperformed traditional artificial bone powder and control groups.

## Abstract

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.

Graphical Abstract