Hypoxic Modulation of Dental Pulp Stem Cell Viability: an In Vitro Study

IntroductionTo investigate the effects of chronic hypoxic exposure simulating heavy-industrial environments on the viability, metabolic activity, stemness preservation, and osteogenic differentiation potential of human dental pulp stem cells (hDPSCs). MethodsCommercially available hDPSCs were cultured under controlled oxygen tensions representing surface atmospheric conditions (21% O2), moderate hypoxia (10% O2), deep hypoxia (5% O2), and severe hypoxia (1% O2). Cells were maintained for 1, 3, and 7 days. Cell viability was evaluated using MTT and Live/Dead assays. Reactive oxygen species (ROS) accumulation, mitochondrial membrane potential, and apoptosis were assessed using fluorescent probes and Annexin V/PI staining. Stemness marker expression (SOX2, OCT4, NANOG) and osteogenic markers (RUNX2, ALP, OCN) were analyzed via RT-qPCR. ResultsModerate hypoxia (10% O2) promoted transient increases in stemness marker expression and preserved metabolic activity. Severe hypoxia (1% O2) significantly reduced cell viability, increased ROS accumulation, disrupted mitochondrial integrity, and elevated apoptotic cell populations after prolonged exposure (p < 0.05). Osteogenic differentiation markers were significantly downregulated under severe hypoxic conditions. ConclusionsIndustrial hypoxic environments critically influence pulpal stem cell physiology and regenerative potential. While moderate oxygen reduction may transiently preserve stemness characteristics, chronic severe hypoxia impairs viability and osteogenic functionality. Chronic low-oxygen occupational environments may alter endogenous dental regenerative mechanisms and influence oral tissue healing responses.