NFKB1 and periodontitis: In summary, our study provides new insight into the double-edged-sword effect of IL-1β by showing that different concentrations of IL-1β, ranging from physiologically healthy levels to those observed in cases of chronic periodontitis, have different effects on the osteogenesis of PDLSCs via crosstalk between the NF-κB, MAPK and BMP/Smad signaling pathways.