“…Isaka et al 22 reported that the periodontal ligament has the ability to regenerate bone, and Flores et al 23 regenerated periodontal tissue using cultured periodontal ligament cells. The periodontal ligament also contains TGF‐β, IGF‐I, basic fibroblast growth factor, vascular endothelial growth factor, BMP‐2, platelet‐derived growth factor (PDGF), and type I collagen 24 . Furthermore, dentin and cementum contain proteins common to bone, such as osteopontin (OPN), bone sialoprotein (BSP), osteocalcin, dentin sialoprotein (DSP), dentin matrix protein‐1 (DMP‐1), type I collagen, osterix, and Cbfa1 (Runx2).…”