An in vitro study on the effects of photobiomodulation by diode lasers (red, infrared, and red-infrared combination) on periodontal ligament mesenchymal stem cells treated with bisphosphonates

This study evaluated the effect of photobiomodulation therapy (PBMT) using 660 and 808 nm diode lasers (individual and in combination) on periodontal ligament mesenchymal stem cells (PDLSCs) in the presence of zoledronic acid (ZA). PDLSCs were cultured for 48 h in DMEM complete medium containing 5 μM ZA. PBMT was done three times with a 24-h interval in groups 1 (660 nm, 5 J/cm ), 2 (880 nm, 3 J/cm ), and 3 (660 + 808 nm) either in normal or ZA-treated culture medium. Control groups did not receive PBMT. Twenty-four hours post-irradiation, cell proliferation and expression of RANKL and OPG were assessed using MTT and real-time PCR tests, respectively. The results showed a significant decrease in cell viability in ZA-treated cells (p