Clinical Potential of Long-Term Cryopreserved Stem Cells From Impacted Third Molar Pulps for Regenerative Endodontic Procedures: An Ex Vivo Evaluation.

This study aimed to establish a standardised protocol for isolating dental pulp stem cells (DPSCs) from fully impacted third molar teeth and to assess the effect of long-term cryopreservation on their viability for future clinical applications in regenerative endodontics. DPSCs were isolated from 21 impacted third molars. The clinical relevance of these cells was characterised via flow cytometry, confirming that 96% expressed mesenchymal stem cell markers. Seventeen samples were cryopreserved at -86°C for up to 12 months to evaluate biological stability for autologous transplantation. The standardised surgical extraction and isolation protocol yielded a high concentration of therapeutic-grade cells (3.43 × 106 cells/mL). Post-thaw viability remained stable (74% to 99%) over 12 months. Importantly, the cells maintained consistent morphology, suggesting they retained the biological potential necessary for dentine-pulp complex regeneration. The results validate a reliable long-term DPSC preservation protocol, supporting feasible dental stem cell banking and a source of viable cells for regenerative endodontic procedures.