Effects of a low-level diode laser on oral keratinocytes, oral fibroblasts, endothelial cells and osteoblasts incubated with bisphosphonates: An in vitro study

Bisphosphonate-associated osteonecrosis of the jaw may have multiple causes, including altered bone remodeling, angiogenesis inhibition and impact of bisphosphonate on the soft tissues. Successful treatment is difficult. As a positive effect of low-level laser application on wound healing is well known, an in vitro study was designed to analyze the effect of low-level laser (280 mW, 670 nm) treatment on keratinocytes, fibroblasts, endothelial cells and osteoblasts treated with clodronate, ibandronate, pamidronate or zoledronate. Pure irradiation had a positive effect on cell viability, whereas bisphosphonate treatment had a negative impact. Viability was significantly increased in cells treated with bisphosphonates and sequel irradiation. There was no effect when the bisphosphonate medium was irradiated. The revealed effect of laser stimulation on cell viability is not due to an inactivation of the bisphosphonates. These results may support the idea of low-level laser therapy as a supportive therapy in patients receiving bisphosphonates to prevent and treat bisphosphonate-associated osteonecrosis of the jaw.