Photobiomodulatory effects of multi wavelength diode lasers on the proliferation and differentiation of human dental pulp stem cells

Abstract

Photobiomodulation is currently trending as a potential stimulator of several cell lines including human dental pulp stem cells (HDPSc) proliferation and differentiation. This study evaluated the Photo-biomodulatory effects of different wavelength diode lasers on HDPSc proliferation and differentiation. Dental pulp stem cells were recovered from human mature premolar teeth extracted for orthodontic reasons, isolated and cultured followed by irradiation with different wavelength laser diodes (660 nm, 450nm and 810nm, 100 mW, all standardized to continuous mode, for 3 minutes at a distance of 1cm from the cells). Cell proliferation was analyzed at 1, 3, and 5 days by flow cytometry. Cell differentiation was analyzed by Alizarin Red Staining at days 7, 14 and 21. Cell proliferation and differentiation were compared with a negative control where cells were maintained in a culture medium without any irradiation and a positive control where pulp cells were cultured in a growth induction medium - Mineral trioxide aggregate (MTA). One -Way and Repeated measures ANOVA followed by Tukey’s HSD post Hoc test were used for statistical analysis. Proliferating cells were significantly higher in the positive control and Infra-red-PBM groups compared to other groups. (Day 3: p=0.002, Day 5: p=0.00).