What is Irreversible Pulpitis?

Learn what it is all about below
Irreversible Pulpitis
Refers to a pulp (nerve and blood supply) that has severe inflammation and is not capable of returning to a clinical normal pulp.
This occurs once caries/decay has reached the pulp, reversible pulpitis progresses to irreversible pulpitis. At this stage the pulpal state will not heal and if left untreated will result in pulp necrosis (nerve death) followed by swellings. Often, a patient feels a spontaneous dull, throbbing and lingering pain. That can radiate and be difficult to localise. Pain can occur during sleep and Panadol/analgesics may not be effective. Heat will be more significant in the later stages and cold may relieve the pain.
The oral health practitioner will usually take an x-ray radiograph and run a few tests to help form a proper diagnosis. Treatment usually involves root canal treatment or extraction/removal of the tooth. This condition if left untreated can continue through the tooth and start to spread which can be life threatening. As a result, it is important you see an oral health care practitioner to assess and manage the situation.
Important Points In This Section
  • What Is Irreversible Pulpitis
  • Signs and Symptoms
  • Treatment
Pulpitis Progression

If caries/decay starts to progress towards the pulp, you can have a condition called reversible pulpitis. This is when the pulp tissue is mildly inflamed. If caught early and treatment performed, it can allow time for the pulp to return to a non-inflamed condition (Relatively Healthy Pulp).
If you leave caries to progress after the signs from reversible pulpitis, you then get a condition called irreversible pulpitis which can be extremely painful. When left to continue you then get pulp necrosis which is where the pulp tissue dies. Once there is no pulp tissue, there is nothing protecting the inside of the tooth anymore and it allows bacteria and the caries to progress further to the tip of the nerve resulting in apical periodontitis. Once at the tip, it can then start to cause an abscess (collection of pus) and then spread to the face (cellulitis) and then to the rest of the body.

Pulpitis Progression Analogy
See Illustration Above


Pulpitis Progression is like the progression of a house fire. Where by the fire is the plaque imbalance/infection. The smoke alarm is the nerve of the tooth and the fire brigade is the dentist.


Imagine you are cooking and have become distracted leaving the room. A fire has started, and the smoke alarm has gone off alerting you to the stove. You call the fire brigade they come and put it out. The pan and some of the walls are now burnt. A little bit of damage but it is fixable because you caught it early. This is similar to reversible pulpitis, usually in that case a filling usually works.


Say you ignored the first couple of smoke alarm sounds, now the second smoke alarm has kicked in. It is louder and even more irritating this is like irreversible pulpitis. Say you have ignored that one too. Now the alarm has melted from the flames, and it is no longer being annoying (this like pulp necrosis). So, you forget about it until you notice smoke coming from the room (this is just like noticing a small swelling in your mouth). You come into the room and now half the house is on fire. You call the fire brigade who come and help put it out. As a result, you have lost some of your house structure. In these situations, you require either root canal treatment or tooth removal. Which depends on the extent of damage.


Say you have ignored all the alarms and smoke. But now you can see the flames and feel the heat. You notice that it is spreading to neighbouring houses and the bushland. You need to contact the fire brigade as soon as possible. As the fire can now cause serious issues elsewhere. These situations require urgent dental treatment, possibly antibiotics and hospitalisation.

Dental Decay, Caries Animation
Well Done!

If you have finished reading all the information on this page, get a certificate for your hard work.

Still have concerns?

This page provides general information about dental topics. It does not contain all the known facts of this subject and is not intended to replace personal advice from your dentist. If your not sure about anything on this site, contact us or speak to your local oral health practitioner. Make sure you give your local oral health practitioner your complete medical history and dental history.

Toothpaste and Fluoride

Learn more about what is in the tube of toothpaste you use every morning and night.

read more
Dental Crown

A custom-made 'cap' that is placed over your tooth

read more
Root Canal Treatment

Treatment perform to the inside of an infected tooth to relieve and prevent pain.

read more

A selection of the references used:
Goldberg, Michel (2014). The Dental Pulp || Pulp Inflammation: From the Reversible Pulpitis to Pulp Necrosis During Caries Progression. , 10.1007/978-3-642-55160-4(Chapter 9), 125–139. doi:10.1007/978-3-642-55160-4_9
Dimitroulis, G. (2008). Illustrated lecture notes in oral and maxillofacial surgery. Quintessence Pub..
Douglass AB, Douglass JM. Common dental emergencies. Am Fam Physician. 2003;67(3):511-516.
Beech, N., et al. (2014). "Management of dental infections by medical practitioners." Australian Family Physician 43: 289-291.
Images adapted:
Adapted from free dental picture by authority dental" (CC BY 2.0) by Authority Dental