Pulpitis – Reversible and Irreversible: Causes, Symptoms, Diagnosis and Treatment

It is a general term for the inflammation of the dental pulp, which consists of blood vessels, nervous tissue and living cells that occupy the hollow interior of the teeth.

Pulpitis is characterized by tooth sensitivity that arises from excess blood flow (hyperemia) in the tooth.

In some cases, the patient will complain of tenderness in the neck, under the jaw or under the chin, where the lymph nodes are located. The lymph nodes usually enlarge and become sensitive when there is infection nearby.

Pulpitis can be caused by any adverse event experienced by the tooth, which includes decay, traumatic injury (a strong blow to the tooth), strong biting forces or puncture in the tooth during dental procedures.

Exposure to solutions that dehydrate or demineralize the tooth can cause it. These can include bleach, acids found in foods and beverages, and even certain multi-care toothpastes.


The pulp (red area of ​​the sketch) consists of blood vessels, nerves and many types of cells. The nervous tissue in the teeth helps us to warn when there are bacterial invaders (caries), cracks and splinters, which can allow microorganisms access to the circulatory system of our body.

The blood vessels in the teeth feed the living cells inside the teeth. For example, the odontoblastic cells that live in the pulp continuously produce dentin (brown area of ​​the sketch) during the whole life of the tooth.

Dentin is a calcified substance that can patch holes created by microscopic cracks and build a dividing wall to slow down the progress of bacteria found in dental cavities. (Sketch by Connor Lambrecht)

Pulpitis is generally divided into two types: irreversible and reversible.

Irreversible pulpitis is usually characterized by prolonged sensitivity to cold and / or heat, and sometimes to sweets. It is often accompanied by a continuous pain of low degree, which is aggravated by these stimuli. Swelling may be present. The ability of the tooth to feel a mild electrical stimulus may be reduced.

With irreversible pulpitis, the nervous tissue is still alive, but it will not remain alive due to the presence of irreversible inflammation in the tooth.


You may experience a toothache if:

  • There is decay.
  • There is gum disease.
  • There is impacted food in your gum.
  • If your tooth has suffered a trauma.
  • There is a crack in your fill or tooth.
  • If you have sinusitis .

The roots of the molar teeth are close to your breast. A sinus infection could make these teeth sensitive to chewing.

There is an underlying pathology of the bone, tumor or cysts, there is no identifiable cause but there is a chronic and distressing pain related to a tooth (atypical toothache).


The intensity of the symptoms may vary:

  • Pain when eating or drinking hot or cold foods / drinks.
  • Dull pain in the jaw.
  • Pain that is spontaneous and throbbing.
  • Pain that can interrupt sleep.
  • Pain that can refer to the head, the temple or the ear.

When to seek help

You should see a dentist immediately if you experience a toothache. Meanwhile, the following may alleviate the discomfort:

  • Avoid hot or cold food.
  • Avoid biting on the tooth involved.
  • Take an over-the-counter pain reliever, such as paracetamol or ibuprofen.
  • If there is an open cavity, apply cotton wool soaked in clove oil (eugenol) in the cavity.


Your dentist will be able to diagnose whether the pulpitis is reversible or not. He will perform tests on the tooth and take x-rays. The treatment will be directed to the cause.

In the case of atypical toothache, where there is no identifiable cause, medication is the treatment of choice. The symptoms do not diminish with the extraction of the tooth in the atypical toothache.

Pulpitis irreversible

It is the inflammatory condition of the pulp, symptomatic or asymptomatic, caused by any noxious stimulus. It is characterized by persistent pain.



  • Abnormal response to cold.
  • Abnormal response to heat.


  • Asymptomatic with exposure to the pulp.
  • Hyperplastic pulpitis.
  • Internal resorption.

Causes of irreversible pulpitis

In case of a large dental filling near the pulp or a trauma to the tooth that can decrease irritation or blood extraction (such as during the treatment of braces).

The deep cavities that extend deep into the dental pulp produce irreversible pulpitis. Gum infections can also lead to irreversible pulpitis.

Symptoms of irreversible pulpitis

From pain to severe unbearable pain occurs in case of irreversible pulpitis. The tooth becomes sensitive even in a slight change in temperature, pain usually persists.

The patient will experience pain even after the stimulus is removed and will last from several minutes to several hours.

A sharp and penetrating pain occurs in case of irreversible pulpitis and the intensity of the pain will become worse when the patient lies down.

Pain referred to the adjacent tooth or pain in the temple region if it is an upper tooth and pain in the ear if it is a lower tooth.

In later stages, a type of throbbing pain occurs. With cold water in the cavity, pain relief occurs.

A rapid onset of pain causes it when cold foods or sweet foods are used.

Pressure of food packaging in the cavity, or pressure exerted by the tongue, which results in congestion of the blood vessels of the pulp.

The pain persists, even after the elimination of the stimuli, and sometimes it can appear and disappear spontaneously without any known cause in particular.

The pain can be sharp, stabbing or penetrating in nature. There may be pain exacerbation when the patient bends or lies down.

The pain can refer to the adjacent teeth sometimes, also to the ear if the lower teeth are involved.

Diagnosis of irreversible pulpitis


It is produced by an intense and unbearable pain. The pain is acute, shooting perforates and gets worse when lying down. In advanced stage, the throbbing or rodent pain occurs in the irreversible pulpitis.

Deep cavity, dental fracture, large dental cavity (secondary caries below the large dental cavity).


The X-rays will show the exposure of the dental pulp or secondary caries below the filling. The normal periapical area is usually there. The tooth is sensitive to percussion.

Intrapulpal pressure increases with exudates in the pulp cavity, which leads to sensitivity in percussion. The heat aggravates the pain and the cold provides some pain relief.

If the probe is sent deep into the pulp, both pain and bleeding would occur.

Bone scan:

It can show the exposure of the pulp, the decay under a filling and the deep cavity. In the periapical area it is usually normal, with some dilatation of the periodontal ligament.


The exudate in the pulp cavity increases the intrapulpal pressure, which leads to tenderness in the percussion of the tooth.

Vitality tests:

The hyperalgesic pulp responds more to stimulation with cold and persists even after the stimulation is eliminated.

The cold later tends to relieve the pain, in comparison with the heat that can intensify the response of the pulp due to the contractile effect in the vessels.

Treatment of irreversible pulpitis

Pulpectomy of the guilty tooth

Complete elimination of the pulp. If it is determined that the case in question is too complex, consult an endodontist immediately.

If the treatment is carried out and the designated treatment time permits, the root canal treatment may be completed in one visit.

Antibiotics are not recommended for irreversible pulpitis, since they will not relieve the patient’s pain and should not be administered instead of immediate pulpectomy.

What is Reversible Pulpitis?

It is generally characterized by a strong sensitivity to cold, sometimes to sweets and sometimes to biting. In general, heat does not bother the tooth so much. In general, there is no low-grade pain, and the painful response to stimuli is not as prolonged.

The swelling is usually not present. Normally, the tooth can still detect a mild electrical stimulus. Within the pulp, the inflammation is not as pronounced as with the irreversible pulpitis, and there has been less tissue damage to the pulp (if any).

If a tooth has recently undergone dental procedures (fillings, crowns, etc.), it may be sensitive for a later period of time. This is known as postoperative sensitivity, essentially a diagnosis of pulpitis.

Depending on the nature of the dental procedure, the patient’s age and immune status, the tooth may improve, or the pulpitis may become irreversible. In some cases, the pulp of the tooth may die.

A dentist can give you an idea of ​​the likelihood of developing pulpitis before dental procedures are performed. Keep in mind that teeth are normally alive, and that dental procedures on teeth are surgical procedures, which commonly produce an inflammatory response of some degree.

Very often the answer is less; however, if the procedure is involved, irreversible pulpitis may occur.

The teeth have at least two types of nervous tissue inside them: myelinated and unmyelinated. These can be considered isolated and not isolated cables.

The myelinated nerves are like isolated wires and carry acute pain stimuli to the brain much faster than the unmyelinated nerves.

The unmyelinated nerves transmit continuous pain of low grade (dull pains). When both types of nerves are affected, there is a good chance that the pulpitis is irreversible.

How does the dentist diagnose Reversible Pulpitis?

One tooth has four possible pulp diagnoses: normal, reversible pulpitis, irreversible or necrotic (dead) pulpitis.

The differentiation between reversible and irreversible pulpitis and the necrotic tooth usually involves the application of warm, cold and mild electrical stimuli. This is done to evaluate how the nerves respond within the tooth, or if they respond at all.

The prolonged painful response to the stimuli supports the diagnosis of irreversible pulpitis. No response to warm, cold or mild electrical stimuli admits a necrotic tooth diagnosis (ie, the tissues it contains are no longer alive).

The acute response to stimuli that decreases rapidly with the elimination of stimuli supports the diagnosis of reversible pulpitis.

Often, a tooth with reversible pulpitis will not be as sensitive to heat. A tooth can have a diagnosis of reversible pulpitis one day and then get worse. Measures can be taken to help prevent that, but they are not always successful.


Reversible pulpitis is often better without treatment. The dentist may recommend the use of nonsteroidal anti-inflammatory drugs (NSAIDs) if you can take them safely. Often, adjusting the bite on the affected tooth speeds up the resolution of symptoms.

Depending on the cause, the dentist can also treat the tooth with desensitizing medications, and may recommend the use of toothpaste with a sensitivity formula until the symptoms improve.

Usually, an x-ray image (x-ray) is taken to obtain a reference record to compare if the symptoms of the tooth do not improve. If reversible pulpitis is caused by tooth decay, fillings or other restorative treatments will be needed.

What dental diagnoses may be related to Reversible Pulpitis?

Dentine hypersensitivity is a condition in which exposed dentin is very sensitive. In general, it is easy to treat, and although its symptoms are similar to reversible pulpitis, its causes may be different.

Teeth that have cracked, chipped or loosened or displaced from a trauma can also hurt and be sensitive. Biting hard or experiencing a strong blow to a tooth can damage your periodontal ligament, causing pain.

This is also known as a concussion injury. Teeth with cavities are sometimes sensitive, especially to cold and sweets.

Patients who have a habit of teeth grinding ( bruxism ) can have several teeth that hurt due to the continuous application of biting forces.

Sometimes, the upper back teeth hurt when the patient has a nasal congestion or infection. Bacterial infiltration of the teeth can produce severe pain and swelling through various types of abscesses, although reversible pulpitis usually does not produce those symptoms unless it worsens.