Peripheral nerve fibers in dentin

Peripheral nerve fibers in dentin are sensory axons originating from the trigeminal ganglion that innervate the dental pulp and extend into the dentinal tubules (StatPearls, 2023). These fibers consist primarily of myelinated A-delta fibers, which transmit sharp, fast pain, and unmyelinated C-fibers, which transmit slow, dull pain (Journal of Endodontics, 2017). According to the hydrodynamic theory, these nerves are activated by the movement of fluid within dentinal tubules in response to thermal or mechanical stimuli (British Dental Journal, 2003). Molecularly, these fibers express various ion channels such as Nav1.7, Nav1.8, and TRPV1, which are essential for nociceptive signaling (Molecular Pain, 2015). Drugs like lidocaine interact with these fibers by blocking voltage-gated sodium channels, while potassium nitrate acts by increasing extracellular potassium concentration to desensitize the nerve (Cochrane Database of Systematic Reviews, 2012). These fibers are the primary mediators of dentin hypersensitivity and pulpal pain, making them key focuses for dental pharmacology.

Other names

Intradental nerve fibersPulpal nerve endingsDentinal axonsA-delta and C-fibers of the dental pulp

Blockade of voltage-gated sodium channels to inhibit action potential propagation; elevation of extracellular potassium levels to induce persistent depolarization and nerve desensitization; occlusion of dentinal tubules to reduce hydrodynamic fluid flow; agonism of TRPV1 channels to induce desensitization.