Figure 3.

Release of signaling molecules by dental pulp stem cells (DPSC) and stem cells from the apical papilla (SCAP) in the initial phase (days 1 to 8), intermediate phase (days 9 to 15), and late phase (days 16 to 21) of culture. Graphs show the secretion of (a) tissue inhibitor of metalloproteinase (TIMP), (b) osteoprotegerin (OPG), (c) interleukin 6 (IL-6), (d) interleukin 8 (IL-8), (e) vascular endothelial growth factor (VEGF), and (f) transforming growth factor beta 1 (TGF-β1). Median values and 25–75% percentiles are based on three independent experiments performed in triplicates (n = 9). For each culture phase, equal lower-case letters indicate pairs that were found significantly different (p ≤ 0.05). One or two apostrophes were added for the intermediate or late phase for a better overview.