Human dental pulp stem cells derived from different cryopreservation methods of human dental pulp tissues of diseased teeth.

BACKGROUND Successful isolation of human dental pulp stem cells (hDPSCs) has been documented at least 120h after tooth extraction. Viable hDPSCs have been isolated chiefly from cryopreserved healthy molar teeth and their undigested dental pulp tissue. Isolation of hDPSCs from diseased but vital teeth after cryopreservation has not been reported. This study aimed to isolate hDPSCs from cryopreserved diseased but vital teeth of various tooth types. MATERIALS Fifty tooth samples were divided into group A (n = 20) - freshly derived dental pulp tissues, group B (n = 20) - liquid nitrogen (liq N(2) )-stored dental pulp tissues and group C (n = 10) - liq N(2) -stored intact teeth. METHODS AND RESULTS The success rate for hDPSCs isolation was 100% for groups A and B and only 20% for group C. hDPSCs from all groups demonstrated self-renewal properties and similar multipotent potential characteristics of adipogenic, chondrogenic and osteogenic differentiation. In addition, hDPSCs showed high expression of bone-marrow mesenchymal stem-cell markers (CD29, CD90 and CD105) and very low expression of specific hematopoietic cells markers (CD14, CD34 and CD45). CONCLUSION Our results indicate that hDPSCs isolated from diseased but vital teeth of various tooth types can be stored in liq N(2) for future usage.