Effect of Photobiomodulation on Osteoblast-like Cells Cultured on Lithium Disilicate Glass-Ceramic

Biomaterials are employed to aid bone regeneration in localized bone defects, especially when there is a great loss of tissues, compromising their ability to repair. A new generation of lithium disilicate glass-ceramic presents favorable characteristics for bone reconstruction, such as high strength and bioactivity. In turn, photobiomodulation therapy has been studied in order to stimulate bone metabolism since it acts as a modulating agent for tissue regeneration. In this study, we evaluated the effect of photobiomodulation therapy on the interaction between osteoblastic cells and lithium disilicate glass-ceramic. MG63 cells suspension was seeded on lithium disilicate and glass discs. After 24 h samples were irradiated with a LED device ( = 660 nm) with 50 mW/cm², 2 J/cm² for 40 s. Cell viability was assessed 2, 7, and 12 days after irradiation using MTS assay. Samples previously stained with alizarin red S were observed at a confocal microscope to evaluate calcification of bone matrix. We first observed an increase in the number of cells adhered to lithium disilicate, compared to glass discs on day 2. LED irradiation promoted an increase in the number of cells on day 12 in both irradiated groups, being quantitatively higher on disilicate discs. Disilicate discs also showed a higher deposition of calcium on the extracellular matrix compared to glass. Red light anticipated mineral deposition for all irradiated groups, being earlier for disilicate samples. In conclusion, photobiomodulation therapy anticipated the positive effects of lithium disilicate glass-ceramic on bone matrix formation and mineralization.