Er: YAG Laser Irradiation Promotes Osteogenic Differentiation Of PDLSCs

Er: YAG laser irradiation has been clinically observed to enhance alveolar bone regeneration post-tooth extraction, though the underlying mechanisms remain unclear[1]. This study aims to investigate the effects and mechanisms of Er: YAG laser on the osteogenic differentiation of human periodontal ligament stem cells(PDLSCs). [1] Krizaj D A, Pajk F, Olivi G. The effect of post-extraction socket preservation laser treatment on bone density 4 months after extraction: Randomized controlled trial[J]. Clin Implant Dent Relat Res, 2021,23(3):309-316. The PDLSCs were obtained from clinical samples and approved by the Ethics Committee. PDLSCs were irradiated with Er: YAG laser (LP, 2.4 W, 20 Hz) at a distance of 20 cm for 0(control), 10, 15, and 20 seconds. Cell proliferation, migration, and osteogenic differentiation were assessed using CCK-8, cytotoxicity assays, wound healing assays, osteogenic staining, RT-qPCR, and Western blot (WB). Transcriptomic analysis was conducted to explore signaling pathways, followed by validation through osteogenic staining, RT-qPCR, and WB. Er: YAG laser irradiation for 15 seconds optimally promoted PDLSC proliferation, migration, and osteogenic differentiation without significant cytotoxicity. Transcriptomic analysis revealed that Er: YAG laser upregulated ITGA2 expression, activating the PI3K/Akt pathway to enhance osteogenic differentiation. Er: YAG laser irradiation may act on residual periodontal ligament tissue post-extraction, promoting alveolar bone regeneration by upregulating ITGA2 expression and activating the PI3K/Akt pathway, thereby enhancing PDLSC osteogenic differentiation.