Abstract
Introduction. Teeth with open species were traditionally treated by apexification using calcium hydroxide or mineral trioxide aggregate plug. On the other hand, regenerative Endodontics is a biologically based procedure used to replace the damaged pulp-dentin complex and to regain the normal pulpal physiological functions. This study aims to evaluate the cell count and differentiation potential of isolated stem cells from extracted third molars. Materials and methods. Pulp tissue was collected form 10 extracted third molars, transferred in HBSS, incubated with Collagenase I and then strained. The single cell suspension was washed with phosphate buffered saline (PBS), mixed with trypan blue and vortexed and then loaded into dry hemocytometer for cell count per ml. The DPSCs were plated in a six well plate at a density of 5 X10<^>5 cells containing DMEM and other supplements. Media were replenished every 3rd day for 21 days. Cells were then fixed with 4% paraformaldehyde and stained with 0.25% naphthol AS-BI phosphate solution. Also, cells were fixed in 70% ethanol and stained with 2 % Alizarin Red. Results and discussion. Dental Pulp Stem Cells (DPSCs) were substantially found and equally distributed in all samples.Delayed processing and the presenceof infection were major causes of the reduced number of stem cells. Morphologic distribution of DPSCs showed clear cell branching and integration. DPSCs showed an excellent osteogenic differentiation and calcium production potential. Conclusions. Isolated DPSCs were equal among samples and have a substantial osteogenic differentiation and calcium deposition potential. Contamination and delayed transfer of pulpal tissue negatively influenced the cell count and differentiation potential of DPSCs. Finally, dental pulp of extracted teeth can be used as an endogenous source of stem cell for future regenerative endodontics procedures (RE).