Pulpitis is inflammation of the dental pulp resulting from untreated caries, trauma, or multiple extensive restorations.
Causes of pulpal inflammation can be as follows.
1. Mechanical cause (traumatic accident, iatrogenic damage at a dental procedure, attrition, abrasion).
2. Thermal cause (uninsulated metallic restoration, cavity preparation with no cooling).
3. Chemical cause (inappropriate use of acidic dental materials).
4. Bacterial cause (the pulp is damaged by bacteria and their toxins from a carious cavity).
PATHOGENESIS OF PULPITIS
The following mechanisms of pain are distinguished:
1. The pulp is located in an enclosed space, the pulp chamber, and as soon as inflammative hyperemia and exudation occurs, the inflamed tissue increases its volume but there is no space for it in the pulp chamber, so the exudate compresses and irritates nerve fibers.
2. Irritation of nerves fibers with mediators of inflammation and low pH always occurs at the inflammation area.
The starting mechanism in acute inflammation of the pulp is alteration, that is, damage of all its components: cells, intercellular substance, fiber and neurovascular component. Accumulation of polymorphonuclear white blood cells and their subsequent alteration leads to a release of lysosomal enzymes (hydrolases, protease, phosphatase), and leads to degranulation of
macrophages, and then - to a release of plasma and cellular mediators of inflammation.
This results in microcirculatory disorder (slowed down blood flow, pronounced hyperemia, stasis, vasculitis, clottage, i.e. thrombosis) leading to hypoxia and increased permeability of the vascular wall. Hypoxia results in disruption of metabolism in the pulp. Due to the circulatory disturbances in the inflamed pulp, and intracellular and intercellular edema in all layers of the pulp, there is a periodic compression of the nerve receptors, which triggers spontaneous paroxysmal pain (an attack can last for 10-30 minutes).