Interaction between the autonomic and sensory nerves in the dental pulp.

The function of intradental sensory receptors is strongly affected by activation of the sympathetic nerves. This effect is most probably indirect and due to changes in pulpal blood flow. Also, in inflamed teeth the sensitivity changes of pulp nerves seem to be closely related to changes in the blood flow. Such inflammatory mediators as histamine, bradykinin and serotonin affect the sensitivity of intradental receptors in pulpal inflammation. In addition, many neuropeptides, for example substance P (SP) and calcitonin gene-related peptide (CGRP), seem to be involved and may interact with histamine or bradykinin. Recent studies indicate that intradental nerves with their neuropeptides may play a significant role in the inflammatory and defence reactions of the dental pulp.