Irreversible pulpitis is a persistent inflammatory condition of the pulp, symptomatic or asymptomatic, caused by a noxious stimulus.
Acute irreversible pulpitis exhibits pain usually caused by hot or cold stimulus, or pain that occurs spontaneously. The pain persists for several minutes to hours, lingering after removal of the thermal stimulus.
The most common cause of irreversible pulpitis is bacterial involvement of the pulp through caries, although any clinical factor, chemical, thermal or mechanical, already mentioned as a cause of pulp disease may also cause pulpitis. As previously stated, reversible pulpitis may deteriorate into irreversible pulpitis.
In the early stages of irreversible pulpitis, a paroxysm of pain may be caused by the following; sudden temperature changes, particularly cold; sweet or acid foodstuffs; pressure from packing food into a cavity or suction exerted by the tongue or cheek; and recumbency, which results in congestion of the blood vessels of the pulp.
2. The patient may also state that bending over or lying down, that is change of position, exacerbates the pain; changes in intrapulpal pressure may be the cause.
3. The patient may also have pain referred to adjacent teeth, to the temple or sinuses when an upper posterior tooth is involved, or to the ear when a lower posterior tooth is affected.
4. In later stages, the pain is more severe and is generally described as boring, gnawing, or throbbing, or as if the tooth were under constant pressure.
The pulp need not be macroscopically exposed, but a slight exposure is generally present, or else the pulp is covered with a layer of soft, leathery decay.
5. When no outlet is present, whether because of a covering of decay or a filling or because of food packed into a small exposure in the dentin, pain can be most intense.
6. Patients are often kept awake at night by the pain, which continuous to be intolerable despite all their efforts at analgesia. Pain is increased by heat and is sometimes relieved by cold, although continued cold may intensify the pain.
7. After exposure and drainage of the pulp, pain may be slight, manifesting itself as a dull consciousness, or it may be entirely absent.
8. Pain can return if food packs into the cavity or underneath a leaky filling; it may not be as intense because of degeneration of the superficial nerve fibers.
9. Apical periodontitis is absent, except in the later stages, when inflammation or infection extends to the periodontal ligament.
Inspection generally discloses a deep cavity extending to the pulp or decay under a filling. The pulp may already be exposed.
On gaining access to the exposure, one may see a grayish, scum-like layer over the exposed pulp and the surrounding dentin. The surface of the pulp is eroded.
At this level, both pain and hemorrhage may occur. If the pulp is not exposed by the carious process, a drop of pus may be expressed when one gains access to the pulp chamber.
It may disclose an interproximal cavity not seen visually, or it may suggest involvement of a pulp horn.
A radiograph may also show exposure of the pulp, caries under a filling, or a deep cavity or filling
3. Vitality Tests:
The thermal test may elicit pain that persists after removal of the thermal stimulus. In the late stages, when the pulp is exposed, generally it reacts feebly to heat and cold.
The electric pulp test induces a response with a marked variation in current from the normal. Results of examination for mobility and percussion and palpation tests are negative.
Other symptoms may develop, such as diffuse, dull, constant pain, characterized by throbbing and gnawing and the tooth may respond abnormally and severely to heat. This response generally is indicative of a later stage of irreversible pulpitis.
The pain of pulpitis is easy to localize by the patient at the onset. Once discomfort increases, the patient loses the ability to identify a particular tooth in the quadrant.
Treatment consists of complete removal of the pulp, or pulpectomy, and the placement of an intracanal medicament to act as a disinfectant or obtundent, such as cresatin, eugenol, or formocresol.
The prognosis of the tooth is favorable if the pulp is removed and if the tooth undergoes proper endodontic therapy and restoration.
One must distinguish between reversible and irreversible pulpitis. In reversible pulpitis, pain produced by thermal stimulus disappears as soon as the stimulus is removed, whereas in irreversible pulpitis, the pain lingers after the stimulus is removed, or it can occur spontaneously