Characterization of stem cells obtained from the dental pulp and periodontal ligament of deciduous teeth

Many studies have found adult stem cells in human teeth or correlated tissues. However, most of these stem cells were found in the permanent teeth or pulp from exfoliated deciduous teeth. The aim of the present study was to characterize stem cells isolated from the functional dental pulp and periodontal ligament of deciduous teeth. Dental pulp tissue was obtained from deciduous teeth by extirpation during treatment for dental caries, and periodontal tissue was obtained from deciduous teeth that were extracted for orthodontic reasons or space management. We observed cell outgrowth from these tissues in 'explants culture', and named these cells as deciduous dental pulp stem cells (DDPSCs) and deciduous periodontal ligament stem cells (DPDLSCs), respectively. These stem cells presented embryonic stem cell markers (Oct-4 and Nanog), an ectomesenchymal stem cell marker (Nestin), and mesenchymal stem cell markers (Stro-1 and CD146). In differentiation media, DDPSCs and DPDLSCs were able to change into cells that produce lipid vacuoles or cells that induce extracellular mineral aggregation, expressing genes correlated with adipogenesis (PPARγ2 and LPL) or osteogenesis (ALP and BSP), respectively. This is the first report of the presence of multipotent stem cells in the functional dental pulp and periodontal ligament tissue of deciduous teeth, which can be isolated using an explants culture method. These tissues can be obtained easily during routine dental procedures, and could therefore represent a good source of adult stem cells for use in regenerative medicine.