NGF and periapical periodontitis: Transplantation of processed autologous dental pulp with growth factors (vascular endothelial growth factor-2 (VEGF-2), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), nerve growth factor (NGF), and bone morphogenetic protein-7 (BMP-7)) embedded in a chitosan hydrogel scaffold was useful in regenerating pulp and dentin-like tissues in necrotic immature permanent teeth with apical periodontitis in dogs [141] with promising results.