Method: Odontoblast-like cells MDPC-23 were seeded (104 cell/cm²) and maintained in DMEM supplemented with 10% fetal bovine serum (FBS) for 12h. After, culture medium was changed by a new DMEM with 0.5% of SFB, during 12h, in order to induce a nutritional stress. The irradiation procedures were performed using a blue LED (455 nm wavelength), at 20 mW/cm² power density, and 2 or 4 J/cm² energy dose. Cellular viability (AlamarBlue Assay), number of viable cells (Trypan Blue Assay), total protein production (TP), total collagen production (Sircol Red Assay), alkaline phosphatase activity (ALP), mineralized nodules formation (Alizarin Red Assay), and cellular morphology (Scanning Electron Microscopy-SEM) were evaluated after 72h from exposure to LED. Data were obtained from two independent experiments (n=12) and analyzed by Kruskal-Wallis and Mann-Whitney tests (p<0.05).
Result: Although there was no difference in cellular viability between the control and the 4 J/cm²-irradiated group, that energy dose increased the number of viable cells. There was an increase in TP for both energy doses compared to the control, while there was no difference in total collagen production. Conversely, ALP activity and mineralized nodules formation were reduced after both irradiation doses. Cellular morphology did not differ among groups.
Conclusion: Odontoblast-like cells MDPC-23 were biostimulated after a single irradiation with 4 J/cm² delivered by a blue LED at 20 mW/cm2 power density.