A short-term treatment with tumor necrosis factor-alpha (TNF-α) enhances migration and colony-forming ability of dental pulp stems (DPCs). (A) Analysis of colony-forming ability of DPCs. Treatment with TNF-α increased the ability of DPCs to form colonies. The graph on the right shows the quantitative analysis of the total number of cell clusters containing more than 50 cells. Data are representative of three independent experiments performed with triplicate samples. (B) Migration assay of DPCs. The images on the left are representative of three different experiments. The graph on the right shows the quantitative analysis of the total number of migrated cells counted in four different pictures taken from each chamber. TNF-α-treated DPCs presented higher migration ability compared with untreated controls. ***P <0.001, unpaired t test.