Authors: Van Hassel HJ.
Title: Physiology of the human dental pulp.
Journal: Oral Surg Oral Med Oral Pathol
Date: Jul 1971
Citation: 32(1):126-34
Category: Endodontic Biology, Histology and Physiology
Evidence-based Ranking: 5
Purpose/Objective: To discuss pulp microcirculatory physiology.

Discussion: Pulp tissue fluid pressure was measured by drilling a 1mm diameter channel with a hand-operated twist drill. The tap was considered complete when clear pulp tissue fluid is seen rising from the surface of the pulp. A cannula is screwed in the tap hole and connected to a transducer to record tissue osmotic pressure. Average tissue pressure in healthy pulps was found to be about 25mm Hg (after several hundred experiments over 7 years). A lower than normal tissue osmotic pressure implies inadequate blood supply to the pulp. This has been shown to occur when local anesthetic solutions containing high concentrations of vasoconstrictors are deposited in proximity to vessels supplying the pulp or when the tooth is in hyperocclusion. The pulp is thought to be vulnerable to prolonged periods of inflammation wherein capillary pressure is elevated and capillary permeability increases. This increased tissue volume causes additional stress to the pulp; the tooth with its rigid walls cause large increases in pulp tissue pressure and cause collapse of the pulpal veins.

ReviewerÂ’s comments: A review of pulpal circulation circa 1971.