The Effect of Low-Level Laser Therapy on the Viability of Human Dental Pulp Stem Cells

Abstract

Introduction: This study assessed the effect of low-level laser (LLL) irradiation on the viability of dental pulp stem cells (DPSCs). Methods: In this in vitro experimental study, human DPSCs were purchased from the cell bank of Iranian Genetic Resources and cultured in flasks containing Dulbecco's modified Eagle's medium supplemented with 20% fetal bovine serum (FBS) at 37°C, 5% CO2, and 95% humidity. The cells were stored in semi-confluent form, and the culture medium was refreshed every two days. The cells in the control group were not laser-irradiated, but the cells in the experimental groups were irradiated with 660-nm and 808-nm diode lasers with 4.1 J/cm2 energy density. Cell viability was assessed at baseline and after 24, 48, and 72 hours using the methyl thiazolyl tetrazolium (MTT) assay. The effects of laser irradiation, laser wavelength, and time on the percentage of cell viability were analyzed by two-way ANOVA and Tukey's test. Results: The effects of laser irradiation and its wavelength (P=0.04), time of assessment (P<0.001), and the interaction effect of group and time (P=0.02) on cell viability were significant. Cell viability in 660-nm and 808-nm laser groups at 48 and 72 hours was higher than that of the control group; however, only the difference in cell viability between the 660-nm laser group and the control group at 72 hours was statistically significant (P=0.03). Conclusion: Considering the optimal effect of diode laser irradiation (particularly 660 nm) on the viability of DPSCs, we conclude that it may be suitable for relevant clinical applications.

Photobiomodulation therapy enhances neural differentiation of dental pulp stem cells via ERK1/2 signaling pathway

“…25 In a previous study, the wound healing process was accelerated by the administration of a GaAlAs laser (810 nm) in a rat model. Furthermore, Asnaashar et al 26 showed that the viability of cells derived from the third molars was higher in the 660 and 808 nm laser groups at 48 and 72 h than that in the control group. As for the energy dose, light doses ranging from 0.5 to 10 J/cm 2 were reported to promote cell proliferation.…”

A Preliminary Investigation into the Effect of Low-Energy Lasers on Dental Pulp Stem Cell Proliferation and the Associated Mechanism

“…Studies have shown that LLLT promotes the proliferation of periodontal stem cells, dental pulp stem cells (DPSCs), bone marrow mesenchymal stem cells, etc. [10][11][12]. The potential clinical application of DPSCs in regenerative medicine is therefore quite high [13].…”