Fig. 5.

Mineralized nodules were examined by Alizarin red S staining. dental papilla cells were incubated with the condition medium (A: OS−M−,B:OS−M +, C:OS + M−, D:OS + M +) for 21days, then the Mineralized nodules were stained by Alizarin red S and Alizarin red S bound to cultures was extracted by incubation with 250 μL of 1% hydrochloric acid in 70% ethanol. The absorbance was measured at 450 nm wave in an ELISA plate reader. Melatonin stimulated the mineralized matrix formation significantly (E) (*P < 0.05, compared to OS−M−, #P < 0.05, compared to OS + M−).Scale bars = 100 μm for A, B, C, D.