Abstract
Formation of nerves and blood and lymph vessels and their remodeling are considered to occur after tooth replantation. Vascular endothelial growth factor (VEGF)-A and VEGF-C are regulatory factors of blood and lymph neovascularization, respectively. Although the expression of VEGF-A in pulp vascular endothelial cells, odontoblasts, and pulp fibroblasts under normal conditions, endothelial cells and fibroblasts in tooth movement has been reported, there have been no previous reports on VEGF-A, VEGF-C, or VEGFR-3 after replantation of extracted teeth in rats. In this study, maxillary right first molars were extracted and replanted immediately after the extraction in rats, and the pulp were immunohistochemically investigated after 1 and 3 days fixed by perfusion with 4% paraformaldehyde solution. The maxilla was excised dissected with teeth from all groups, and 5.0-mm3 blocks were prepared. The blocks were decalcified with 10% EDTA at 4°C for 2 weeks, dehydrated with alcohol by the standard method, and embedded in paraffin. The blocks were then cut into thin sections using a microtome, and VEGF-A and VEGF-C protein expressions were investigated by immunohistochemical staining using antibodies against these proteins and the ABC kit. To clarify the cell nuclei, the sections were stained with methyl green after immunohistochemical staining. The sections were observed under a universal microscope. VEGF-A expression in the pulp was weakly positive in perivascular fibroblasts and odontoblasts in the control group. At 1 day post replantation, VEGF-A was positive in these cells, and strongly positive in the Weil layer. VEGF-C expression was weakly positive in perivascular fibroblasts in the control group, and positive in fibroblast and odontoblast at 1 day post replantation. The VEGFR-3 expression pattern was similar to that of VEGF-C. Based on the above findings, expressions of regulatory factors that increase blood and lymph vessels in dental pulp, VEGF-A and VEGF-C and VEGFR-3, were promoted after replantation of extracted teeth, and odontoblasts were suggested to be related to the production of these factors.
