Effect of low-level laser therapy on bisphosphonate-treated osteoblasts

Background This study investigates the effect of alendronate-treated osteoblasts, as well as the effect of low-level laser therapy (LLLT) on the alendronate-treated osteoblasts. Bisphosphonate decreases the osteoblastic activity. Various treatment modalities are used to enhance the bisphosphonate-treated osteoblasts; however, there were no cell culture studies conducted using a low-level laser. Methods Human fetal osteoblastic (hFOB 1.19) cells were treated with 50 μM alendronate. Then, they were irradiated with a 1.2 J/cm 2 low-level Ga-Al-As laser ( λ = 808 ± 3 nm, 80 mW, and 80 mA; spot size, 1 cm 2 ; NDLux, Seoul, Korea). The cell survivability was measured with the MTT assay. The three cytokines of osteoblasts, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF) were analyzed. Results In the cells treated with alendronate at concentrations of 50 μM and higher, cell survivability significantly decreased after 48 h ( p