Parvalbumin-like immunoreactivity in nerve fibres within human molar tooth pulps

The root pulp contained two types of parvalbumin-immunoreactive nerve fibres, smooth and varicose. The smooth were relatively thick (mostly 3-5 microns in diameter) and sometimes had large swellings, whereas the varicose consisted of oval varicosities of 1-3 microns in long diameter with very fine strands interconnecting them. Most of the parvalbumin-immunoreactive root fibres were smooth, and the varicose were rare. Upon entering the pulp chamber, both types of fibre splayed out and ran towards the roof of the chamber and the pulp horn. In the subodontoblastic layer of the roof and horn, parvalbumin-immunoreactive fibres showed relatively straight chains of granules; they sent their granular terminals to the odontoblastic layer. Some parvalbumin-immunoreactive granules were observed in the predentine and some even in the dentine. The diameter of axons in the root pulp and the spatial distribution of terminals strongly suggest that the parvalbumin-immunoreactive fibres are mostly myelinated and sensory.