Potential Effects of Photobiomodulation Therapy on Human Dental Pulp Stem Cells

Background: A significant clinical technology enabling the use of stem cells in dentistry is Photobiomodulation (PBM). The current study aimed to investigate various PBM treatment variables on human dental pulp stem cell proliferation, survival, and changes in cell cycle progression. Methods: Human third molar samples were collected, and human Dental Pulp Stem Cells (hDPSCs) were isolated, expanded, seeded, and cultured in media containing 0, 1, 5, or 10% FBS. PBM treatments using an 810 nm diode laser at various doses were performed 24, 48, and 72 h after seeding. Cell proliferation and apoptosis were assessed. A two-way ANOVA test was performed among all treatment groups, followed by multiple comparison tests (Tukey’s test) performed between each treated group and its control untreated group. Results: After 24 h, only cells cultured in 10% FBS showed a significant (p < 0.005) increase in the proliferation rate of cells treated with T7 (0.4 W × 10 s). After 48 h, hDPSCs cultured in both 5% and 10% FBS showed a significant (p < 0.005) increase in the proliferation rate of cells treated with T7 (0.4 W × 10 s) as compared to the untreated control. After 72 h, only cells cultured in 10% FBS showed a significant increase in the proliferation rate of the cells treated with T9 (1 W × 3 s) (p < 0.005) and T7 (0.4 W × 10 s) (p < 0.00005). Conclusions: Low-power laser therapy at a wavelength of 810 nm induced hDPSC proliferation at the following parameters: power output 0.4 W, irradiance 0.5 W/cm², fluence 0.416 J/cm², exposure time 10 s.