Immediate physiological response of odontoblasts.

The normal structure and function of the odontoblast cell layer is often perturbed by a variety of pathological processes as well as by the restorative procedures and materials required to treat them. It is well accepted and documented that a number of acute histological changes may take place under these circumstances resulting in the loss of integrity of the odontoblast cell layer. To date, our understanding of the immediate physiological response of the odontoblast to pathological processes or iatrogenic trauma remains limited. This paper reviews: first, the evidence for and against the existence of physiological barrier between the distal segments of odontoblast cell bodies; second, the alteration of this physiological barrier following routine restorative procedures; third, the role junctional complexes may play in this barrier function, and finally, the role that dental innervation, both afferent and efferent, may play in influencing and regulating the response of the dental pulp to external stimuli.