Effect of low-level laser irradiation on proliferation and viability of human dental pulp stem cells

Abstract

A positive effect of low-level laser irradiation (LLLI) on the proliferation of some cell types has been observed, but little is known about its effect on dental pulp stem cells (DPSCs). The aim of this study was to identify the lowest energy density able to promote the proliferation of DPSCs and to maintain cell viability. Human DPSCs were isolated from two healthy third molars. In the third passage, the cells were irradiated or not (control) with an InGaAlP diode laser at 0 and 48 h using two different energy densities (0.5 and 1.0 J/cm²). Cell proliferation and viability and mitochondrial activity were evaluated at intervals of 24, 48, 72, and 96 h after the first laser application. Apoptosis- and cell cycle-related events were analyzed by flow cytometry. The group irradiated with an energy density of 1.0 J/cm² exhibited an increase of cell proliferation, with a statistically significant difference (p < 0.05) compared to the control group at 72 and 96 h. No significant changes in cell viability were observed throughout the experiment. The distribution of cells in the cell cycle phases was consistent with proliferating cells in all three groups. We concluded that LLLI, particularly a dose of 1.0 J/cm², contributed to the growth of DPSCs and maintenance of its viability. This fact indicates this therapy to be an important future tool for tissue engineering and regenerative medicine involving stem cells.

Transdentinal photobiostimulation of stem cells from human exfoliated primary teeth

“…In the same study, the detection and quantification of mineralization nodules, collagen and VEGF expression was also increased after 0.8 J cm À2 and the expression of DMP1 increased after 4.2 J cm À2 . Moreover, Zaccara et al (2015) demonstrated that 1 J cm À2 of near infrared laser stimulated the proliferation of dental pulp stem cell from human teeth. The results can vary depending on the experimental protocol and irradiation parameters used, but all cases indicate that infrared irradiation can stimulate pulp cells concerning mineralization capacity and proliferation potential.…”

“…Moreover, Zaccara et al . () demonstrated that 1 J cm −2 of near infrared laser stimulated the proliferation of dental pulp stem cell from human teeth. The results can vary depending on the experimental protocol and irradiation parameters used, but all cases indicate that infrared irradiation can stimulate pulp cells concerning mineralization capacity and proliferation potential.…”

Cerebrospinal Fluid and Photobiomodulation Effects on Neural Gene Expression in Dental Pulp Stem Cells

“…Therefore, finding a cellular source to repair damaged neural tissues and treat neural disorders is of great importance. 33 Although the human bone marrow MSCs have been considered as a candidate for treating neural diseases, the high differentiation efficiency and the ease of access to DPSCs make them an attractive alternative source of cells. 34 Besides, DPSCs have been shown to express embryonic stem cell pluripotent markers such as OCT4, NANOG, SSEA4, and TRA-1-60 and also the markers of multipotency indicating the chondrocyte and osteocyte differentiation along with the neural simultaneous differentiation.…”

“…28,29 Finally, developing methods to elevate cell numbers in a short time is a topic of interest and PBM is one of them which has been proposed in the literature. 20,[30][31][32] The purpose of this study was to isolate and culture the human DPSCs and to evaluate the effect of PBM, CSF, and a combination of both on the hDPSC proliferation status and the expression of neural gene markers.…”

Effects of photobiomodulation therapy in dentoalveolar-derived mesenchymal stem cells: a review of literature

“…Zaccara et al [35] also evaluated the viability and proliferation of human DPSCs showing that the cells responded positively to PBMT. These authors also studied cells grown on ideal culture conditions.…”