Figure 1. Morphology of HDPCs isolated by three different methods. (a) Image of HDPCs-OG. Cells were homogenous with a typical fibroblastic shape; (b) Image of HDPCs-ED. Cells were more heterogeneous in shape, mstly fibroblast-like, although some appeared cuboidal or polygonal; (c) HDPCs-Combined were mixed phenotype with HDPCs-OG and HDPCs-ED. Scale bar: 50 µm. HDPCs, human dental pulp cells; HDPCs-OG, HDPCs were isolated by the outgrowth method; HDPCs-ED, HDPCs were isolated by the enzymatic digestion method (collagenase/dispase/trypsin); HDPCs-Combined, HDPCs were isolated by the combination of both methods.