Exposed Tooth Nerve: What Causes It and When to Seek Urgent Care

Few dental problems are as immediately unmistakable as an exposed nerve. The pain is sharp, disproportionate to the size of the tooth, and provoked by things that should be harmless — a breath of cold air, a sip of water, the pressure of a tongue passing over the area.

Patients often describe it as the worst pain they have experienced. That is not an exaggeration of their perception; the dental pulp is densely innervated and confined within rigid walls, and when it is directly exposed the response is intense.

This article explains what is actually happening, what causes it, what you can safely do in the interim, and — importantly — what you should not do.

Inside every tooth is a chamber containing the pulp: a soft tissue made up of nerves, blood vessels and connective tissue. It is normally protected by two layers. The outer layer is enamel, which is hard, mineralised and has no nerve supply of its own. Beneath that is dentine, a softer layer containing microscopic tubules running from the outer surface towards the pulp. Fluid within these tubules transmits stimuli inwards, which is why exposed dentine is sensitive even before the pulp itself is involved.

Strictly speaking, "exposed nerve" is used loosely by patients and can describe two different situations.

Exposed dentine. The enamel is lost or the gum has receded, exposing the tubules. Sensitivity is sharp but short — it stops when the stimulus is removed. This is uncomfortable but not usually urgent.

True pulp exposure. The pulp itself is open to the mouth, through a deep cavity, a fracture, or the loss of a large restoration. Pain is severe and lingering, and bacterial contamination of the pulp is inevitable. This does need treatment.

The practical distinction is duration. Pain that stops within a few seconds of removing the stimulus suggests dentine. Pain that continues for minutes, wakes you at night, or occurs spontaneously suggests the pulp is inflamed or exposed.

Deep decay. The most common route. Decay progresses through enamel, spreads through dentine, and eventually reaches the pulp. Because decay is not painful in its early stages, it is often well advanced by the time it announces itself. This is one of the arguments for regular examination — see our article on cavities in back teeth.

Fracture or trauma. A blow to a front tooth can shear off a corner. If the fracture line crosses the pulp chamber, the pulp is exposed immediately. Our article on broken teeth with swelling covers the more serious presentations.

A lost filling or crown. A large restoration may have been sitting close to the pulp. When it comes out, the remaining dentine can be very thin, and the tooth may become acutely sensitive within hours. Our article on emergency dental bonding covers what can and cannot be done quickly in this situation.

Cracked tooth. A crack can propagate over time until it reaches the pulp. Characteristic symptoms are pain on releasing a bite and sensitivity to cold — our article on cold water sensitivity in broken teeth discusses this pattern.

Severe wear or erosion. Long-term acid erosion or grinding can thin enamel to the point where dentine is widely exposed. Our article on acidic foods and enamel explains the process.

Gum recession. Exposes root surface, which has no enamel covering and is sensitive. See how to manage sensitive teeth and receding gums.

The aim in the interim is to reduce stimulation and manage pain — not to treat the tooth.

Avoid extremes of temperature. Cold is usually the worst trigger. Drink at room temperature, through a straw if that helps direct fluid away from the tooth.

Keep the area clean but be gentle. Continue brushing the rest of the mouth normally. Clean the affected tooth carefully with a soft brush. A build-up of debris around an exposed area makes matters worse, not better.

Warm salt water rinses. A teaspoon of salt in a cup of warm water, used gently, can be soothing and helps keep the area clean.

Chew on the other side. Pressure on an exposed pulp is intensely painful and can worsen inflammation.

Over-the-counter pain relief, taken according to the instructions on the packet and provided it is suitable for you. If you are unsure whether a particular medicine is appropriate given your medical history or other medications, ask a pharmacist. Our article on temporary toothache relief covers this in more detail.

Sleep propped up. Lying flat increases blood flow to the head and often makes dental pain worse at night.

Temporary dental cement from a pharmacy can cover an exposed area where a filling has come out. It is a short-term measure to reduce sensitivity while you wait, not a repair.

Do not place an aspirin against the gum or tooth. This is a persistent piece of folklore and it causes a chemical burn of the soft tissue. Painkillers work by being absorbed, not by contact.

Do not apply undiluted clove oil to the gum. It is caustic to soft tissue in concentrated form and can cause a burn.

Do not poke at the area with anything to explore it. You will contaminate it and increase the pain.

Do not use heat on the outside of the face if there is any swelling — warmth can encourage the spread of infection.

Do not leave it because the pain has stopped. This is the most important item on the list. When an exposed pulp becomes irreversibly inflamed and then the nerve tissue dies, the pain often disappears entirely for a period. This is not recovery. The tooth is now a dead space where bacteria multiply, and the next event is usually an abscess. Our article on apical periodontitis and infection spreading to bone explains what follows.

Seek urgent dental care, and consider urgent medical care via NHS 111 or A&E, if you have:

• Facial or neck swelling, particularly if it is spreading

• A fever or feeling generally unwell alongside dental pain

• Difficulty opening your mouth, swallowing, or breathing

• Swelling around the eye, or that crosses the midline under the chin

• Pain that is not controlled by over-the-counter analgesia

Difficulty swallowing or breathing alongside facial swelling is a medical emergency requiring immediate attention at A&E, not a dental appointment. Our articles on fever with facial swelling and dental abscess symptoms cover the warning signs in more detail.

This depends on the cause and how much of the tooth remains.

Where the exposure is small, recent and in a tooth with an otherwise healthy pulp — typically a fresh fracture in a younger patient — it may be possible to place a protective dressing directly over the exposure and restore the tooth, aiming to keep the pulp alive.

Where the pulp is irreversibly inflamed or has already died, root canal treatment removes the pulp tissue, disinfects and seals the canal system. The tooth is then restored, often with a crown to protect the remaining structure.

Where too little sound tooth remains to restore predictably, extraction may be the realistic option, with replacement discussed afterwards. Our article on choosing between a crown and extraction covers that decision.

Antibiotics are not a treatment for an exposed nerve. They may be prescribed alongside definitive treatment where there is spreading infection, but they do not address the source. See do you need antibiotics for a tooth infection.

How long can I leave an exposed nerve before it becomes serious?

There is no safe interval, and we would not encourage waiting. Once the pulp is open to the mouth, bacterial contamination begins immediately and the tissue does not recover on its own. The pain may fluctuate or even disappear as the pulp dies, but the underlying problem continues to progress towards infection at the root tip. Arrange an appointment as soon as you can rather than waiting to see whether it settles.

Why has my severe pain suddenly stopped?

Most often because the pulp tissue has died. The nerve endings that were generating the pain no longer function, so the sensation ceases. This is a common and misleading turning point — patients frequently interpret it as the problem resolving and cancel their appointment. What follows in most cases is infection spreading beyond the root tip into surrounding bone, which brings a different and often more serious set of symptoms. Please keep the appointment.

Can an exposed nerve heal by itself?

Exposed dentine can become less sensitive over time, because the tooth lays down secondary dentine and the tubules can partially occlude. A truly exposed pulp does not heal spontaneously once it is open to the oral environment. In carefully selected cases — a small, clean, very recent exposure in a healthy tooth — a dentist may be able to place a dressing that allows the pulp to recover, but that requires prompt professional intervention, not waiting.

Is an exposed nerve the same as a dental abscess?

No, though one commonly leads to the other. An exposed nerve means the pulp is open and inflamed. An abscess is a collection of pus that forms when infection from a dead pulp extends beyond the root into the surrounding tissue. Abscess symptoms typically include throbbing pain, pain on biting, swelling and sometimes fever. Our article on telling toothache from an abscess explains how to distinguish them.

Will I definitely need a root canal?

Not necessarily, but it is the most likely treatment where the pulp has been exposed for any length of time. If the exposure is very recent and small, a protective dressing may allow the pulp to survive. If the tooth is extensively broken down, extraction may be more realistic. The decision depends on the size and duration of the exposure, the tooth's response to testing, radiographic findings and how much sound structure remains — all of which need assessing in person.

What can I do about pain during the night?

Take over-the-counter analgesia according to the packet instructions, timing the dose so it is working when you go to bed. Sleep with your head propped up on extra pillows, as lying flat increases blood flow to the head and typically worsens dental pain. Avoid cold drinks in the evening. If pain is not controlled by appropriate over-the-counter medication, or you develop swelling or fever, contact an emergency dental service or NHS 111 rather than trying to get through the night.

If you have an exposed nerve or severe dental pain, please contact us promptly rather than waiting for it to settle. We keep time available for urgent problems and will assess the tooth, establish the cause and discuss the treatment options with you.

Find out more about our emergency dental care, or contact the practice on 020 7183 0692.

This article provides general information and does not constitute individual dental or medical advice. It is not a substitute for examination by a dentist. Any self-care measures described are temporary comfort measures only and do not treat the underlying problem. If you have facial swelling, fever, difficulty swallowing or difficulty breathing, seek urgent medical attention immediately by contacting NHS 111 or attending A&E. Always read the patient information leaflet for any medicine and consult a pharmacist or doctor if you are unsure whether it is suitable for you. Wimpole Dental is regulated by the Care Quality Commission, and our clinicians are registered with the General Dental Council.

Next review due: 11 September 2027