Reversible and Irreversible Pulpitis

To understand how we determine when root canal treatment is necessary, you need to understand the nature of pulpitis.


It is inflammation of the dental pulp. The pulp is the nerve and blood supply that are inside a tooth. When the pulp is inflamed a tooth may become sensitive.

The cause of pulpitis is mainly insults to the pulp. The first cavity (at age 7 possibly) insults the nerve with bacteria. The filling to correct it may insult the nerve mechanically. In later years, the second cavity and the second repair job may add to the insult. A blow to the tooth or undue forces may cause cracks, and therefore insults. Any broken cusp or a crack that can’t even be detected may further insult the pulp and the crown procedure that follows may add insult as well.

In many cases, such as those described above, the dental pulp may become, and stay inflamed and sensitive, but still have a chance to heal and recover. We call this reversible pulpitis, the symptoms of which are as follows: sensitivity that slowly gets better, or sensitivity only when something occurs to cause it, like drinking cold water.

Irreversible pulpitis is when a nerve has been insulted beyond recovery. Tissues in the pulp die and abscess will occur sooner or later. Often the tooth will abscess soon, but it can take months or years to occur.

Irreversible pulpitis means that Root Canal Therapy is necessary if the tooth is to be saved. Symptoms are ever worsening sensitivity, prolonged sensitivity, and pain that lingers awhile after the stimulus is removed. Also, spontaneous pain, not caused by any stimulus is a sign, as well as night awakening pain.

To Summarize:

Reversible Pulpitis
  • Discomfort caused by cold or other stimuli
  • Discomfort relieved when stimulus is removed
  • Symptoms getting slowly better
  • Discomfort easily controlled by over the counter analgesics


Irreversible Pulpitis
  • Spontaneous pain, NOT caused by stimuli
  • Lingering pain, even after stimulus removed
  • Getting worse or lasting too long
  • Discomfort does not respond well to analgesics
  • Night awakening
  • Root canal necessary