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Tooth Nerve Pain - Comprehensive Guide

Updated: Dec 19, 2023

The pulp of your tooth contains an overabundance of nociceptors (pain receptors), which get triggered by a variety of external stimuli and dental conditions. Tooth nerve pain occurs whenever you feel pain or sensitivity from the pulp nociceptors being activated.

What this article will cover:

How your tooth nerve causes you pain

The pain receptors in the pulp consist of A-delta fibers and C fibers, which are afferent endings of the trigeminal nerve (cranial nerve V). The A-delta fibers are located more superficially along the junction of the dentin as well as the pulp. The C fibers are located more centrally in the pulp. Both fibers exit the tooth via the tip of the root and join the main trunk of the trigeminal nerve to travel up to the brain where they deliver their pain signals.

Tooth nerve pain occurs when stimuli triggers both of the fibers or a single one of them. The fibers will send their pain signals out through the root of the tooth and directly up to the brain via the central nervous system (CNS).

However, the A-delta fibers and the C fibers serve different functions and also get activated based on different criteria.

A-delta fibers in tooth nerve

The A-delta fibers are one of the first nerves to transmit pain signals due to their low stimulation threshold. They will get activated even when there is no irreversible nerve damage.

Here are some of their clinical features:

  • Myelinated axons

  • Fast conduction speed

  • Low stimulation threshold

  • Superficially located

  • Generates a sharp and stabbing pain

  • Pain is easily localized

  • Will send pain signals regardless of the damage being reversible or irreversible

Here are the types of stimulation, which may trigger the A-delta fibers:

  • Hydrodynamic stimuli

  • Drilling into the tooth - example would be getting a d

  • Sweet foods

  • Acidic foods

  • Cold air

  • Hypertonic solutions such as teeth whitening gels

What this means is that if you're having pain or sensitivity from drinking cold fluids or eating sweet foods, it is most likely the A-delta fibers which are being triggered.

C fibers in tooth nerve

The C fibers are located much deeper into the pulp of the tooth than the A-delta fibers. Their stimulation threshold is also much higher and don't usually activate unless there is irreversible damage to the tooth nerve.

Here are some of their clinical features:

  • Unmyelinated axons with smaller diameters

  • Low conduction speed

  • High stimulation threshold

  • Diffuse pain that refers pain elsewhere

  • Dull and aching pain

  • Burning sensation

  • Sends pain signals when irreversible damage occurs

  • Continues to function even after the A-delta fibers inactivate

The types of stimulation which activate the C fibers:

  • Heat

  • Pulp decay

  • Infection in the pulp

What this means is whenever you experience that type of tooth nerve pain that is dull and aching even while you're NOT doing anything, it is most likely the C fibers sending pain signals. They're the nerves that tend to predominate and take over as your dental condition worsens.

Common causes that trigger pain in your tooth nerve

There are numerous types of stimuli which can trigger tooth nerve pain and the vast majority of them are common everyday occurrences.

  • Foods. Hot, cold, sweet, acidic, and spicy foods will all activate the nerve fibers in your tooth. That change in temperature or pH in your mouth will be sensed by your tooth.

  • Exposed dentin. The dentin layer has a lot of A-delta nerve fibers running through the tubules. They have a low stimulation threshold for pain and sends signals very quickly back to your brain. This category also includes chipped and fractured teeth which will leave the dentin exposed.

  • Receded gums. The gums normally cover the root surface of your teeth but once the gums recede, they will become exposed. The roots are much more sensitive and not use to a lot of external stimuli. Therefore, anything that touches it will cause sharp sensations.

  • Tooth decay. Decay that is in the enamel may not cause any symptoms but once they progress through the stages of tooth decay, it will become sensitive. If the cavity is big enough it can even be painful and that is especially true once the decay reaches the pulp, where it is filled with nerve endings.

  • Tooth abscess. An abscess occurs once the pulp gets obliterated by the infection, which then travels out of the tooth and eats away the bone surrounding the root. Typically at this stage of a tooth abscess, it is mostly just the C fibers that are sending pain signals.

  • Teeth grinding. If you grind your teeth at night, you will wear through the enamel layer of your teeth and leave the dentin exposed. The enamel is not alive but the dentin is filled with the A-delta nerve fibers. That means, these pain receptors are wide open to all sorts of stimuli to trigger pain.

  • Teeth whitening. Aside from whitening your teeth, the second major side effect of teeth whitening is sensitivity. The pain occurs due to the difference in hypertonicity of the whitening gel compared to the tooth. The gel pulls fluids out of the tooth and also enters the tubules to stimulate the nerve endings. Therefore it acts as a double whammy in causing you tooth nerve pain.

How to stop tooth nerve pain

In order to stop the pain coming from your tooth nerve, you would need to address the root cause of the pain. The treatment will attempt to prevent the stimuli from activating the pain receptors. Some of these treatments may be used for more than one dental condition.

Home remedy - Sensitivity toothpaste

The vast majority of people experience sensitivity while eating certain foods. In order to prevent these foods from triggering pain signals to your tooth nerve, a sensitivity toothpaste may be used such as Sensodyne.

Sensitivity toothpastes often contain potassium nitrate, which can desensitize the tooth nerve by preventing it from firing. How it works is that by brushing with potassium nitrate, it will start to accumulate overtime around the pulp. Once it reaches a certain concentration, it prevents the nerve fibers from firing.

What should be emphasized for this treatment method is that it typically takes about 2-3 weeks of using the product before you see any results. This means that if you're looking for a remedy that will stop the tooth nerve pain immediately, you may need to look elsewhere.

Other dental conditions it may help with:

  • Receded gums - potassium nitrate in toothpaste works wonders for desensitizing receded gums that are painful or sensitive.

  • Exposed dentin - certainly can help with relieving pain for exposed dentin but a sensitivity toothpaste isn't a permanent solution for dentin that is exposed.

Tooth filling and dental bondings

If the nerve pain is coming from tooth decay, the solution would be to see your dentist for a cavity filling. The stimuli which would be the cavity would have to be removed. Afterwards a dental filling material will replace the lost tooth structure.

Dental bondings can also be used as an alternative to sensitivity toothpastes to suppress pain coming from the tooth nerves. For instance, instead of using it on receded gums or exposed dentin, you can simply bond a filling to cover up the sensitive spots. This is actually a much more robust long term solution for those two problems. The toothpaste needs to be continually used while a filling will last until it breaks.

Root canal

If the pain is coming from an infected pulp or abscessed tooth, treatment would most likely involve a root canal. This procedure extracts the unhealthy nerve and cleans out the inside of the tooth of all infection. Afterwards, you will require a dental crown to be placed over the tooth to protect its structural integrity.

Tooth extraction

Sometimes if the nerve pain coming from your tooth is beyond unbearable, you may also opt to have the tooth removed. If you extract the tooth that is bothering you, the symptoms will of course go away with it.

However, this procedure is usually reserved for a tooth that has a poor prognosis or the patient cannot afford alternative treatment options due to finances.

Stop whitening your teeth

If you're having tooth is having extreme nerve pain from excessive teeth whitening, the only way to stop it would be to cease using the material. The pain should resolve within a few days of stopping the product.

However, if you want some additional relieve from the pain here are some methods you can try:

  • Pain medication - take some ibuprofen or tylenol to help kill some of the pain.

  • Sensitivity toothpaste - brush with a toothpaste that contains potassium nitrate. You can also rub some of the toothpaste onto the sensitive teeth and let it marinade. The sensitivity effect works based on contact time so the longer you leave it on, the better it would work. You can even leave the toothpaste on for 30 minutes.


Pain from your tooth nerve occurs when the pain receptors within the tooth become stimulated in any way shape or form. The stimuli are usually in the form of foods that you eat, cavities, infections, abscesses or even teeth whitening. The treatment typically involves stopping the offending activity and getting rid of the source of what is causing it.

Nonetheless, if you're having pain that you're unable to get rid of you need to seek medical help. Our team of emergency dentists in Long Island City can assist you if you're in the tristate area.



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About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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