Study On Difference Between Blood Vessels And Nerve Fibers In Human And Rat Pulp

Objective: The aim of this study was to reveal the difference between blood vessels and nerves in human and rat pulp.Method: Human premolar teeth and primary teeth,extracted for orthodontic reason and deciduous tooth retention,rat maxilla and mandible,rat pups tooth germ dissected were placed in 4 % para formaldehyde.The presences of blood vessels(vascular endothelial growth factor VEGF),nerves(neurofilament heavy NFH)and myelinated nerve fiber(myelin basic protein MBP)were examined in the pulp by using immunohistochemistry(IHC)markers.The pulp region was examined to determine the distribution and the integral optical density(IOD)of blood vessels and nerves by using fluorescence microscopy and Image pro plus 6.0.Result:(1)Nerve fibers were seen to run along the blood vessels in the human and rat dental pulps.Myelinated nerve fiber was in the human peripheral area of the dental pulp,but appeared at central area of the rat molar pulp.(2)The distributions of human pulp nerves were appeared to vessel wall and perivascular space but the rat pulp only existed in vessel wall.(3)There were significant differences in blood vessels between human and rat teeth at root and chamber(P< 0.05),and the proportion of nerve fibers of human was significantly different from that and rat teeth at root and chamber(P< 0.05).(4)The process of physiological root resorption of deciduous teeth,blood vessels and nerves gradually degeneration,disappearance,and blood vessels began to degenerate earlier than nerves degenerated;newborn blood vessels and nerve fibers could be observed in the embryonic rat molar,myelinated nerve fibers not yet developed.Conclusion: The distribution and proportion of blood vessels and nerve fibers in rat molar teeth were significantly different from that of the human teeth,which indicated that the rat molar teeth could not a valid model for human teeth research.