Population doubling time (PDT) of DPSCs cultured in the presence of basal culture medium for undifferentiated DPSCs.

<p>The graph shows in vitro passage (starting from p2 for young cells (black bar) to p8 (white bar)) and the age of the donor (from 16 to over 67). T tests were used to determine significant differences (p<0.05). * p<0,05; * * p<0,01; * * * p<0,001.