While it’s normal to feel some mild pain or discomfort after a root canal procedure, this pain typically fades within a few days. Experiencing pain in your tooth months after a root canal is a sign that something may be wrong and shouldn’t be ignored.
Root canal treatment carried out to a high clinical standard in the UK carries a success rate of up to 90%. However, as with all dental treatment, there is a chance that things can go wrong. If you are dealing with throbbing or sharp pain months after your root canal treatment, understanding why it may be happening can help you make sure you get the right treatment.
In this blog, we’ll cover why your root canal tooth may be hurting after months and what next steps you should take.
Is pain months after a root canal normal?
In short: no.
Mild tenderness or discomfort in the days following a root canal is normal, but persistent or late-onset pain is not.
A root canal removes the infected nerve (pulp) from inside the tooth. Because the nerve endings within the tooth are gone, the tooth should no longer feel temperature changes or acute internal pain.
‘When a root canal fails months later, patients are often confused because the nerve was removed. Late-onset pain is almost always a sign that bacteria have reinfected the root system or surrounding bone. Whether due to a missed canal, an inadequate seal, or a broken file, persistent pain shouldn’t be ignored. It requires prompt investigation from a dental professional to prevent further complications.’ – Chris Dean, Joint Managing Director at the Dental Law Partnership.
Common reasons a root canal tooth might hurt months later
1. Reinfection or hidden canals
Tooth roots are surprisingly complex, often featuring microscopic branches that are easy to miss. If a dentist misses one of these tiny spaces during treatment, bacteria left inside can slowly multiply and cause a new infection months down the line.
According to UK dental research, up to 90% of upper back teeth (molars) have a hidden second canal. If a dentist misses this tiny space, lingering bacteria can cause an infection months later.
2. A loose, cracked, or leaking crown
After a root canal, the tooth is usually capped with a crown or permanent filling to protect it from bacteria. If this seal is loose, cracked, or poorly fitted, bacteria from your saliva can seep underneath, leading to new decay and infection.
3. Fractured tooth or cracked root
Teeth that have had root canal treatment become brittle over time because they no longer receive blood flow. A tiny crack in the root or crown can develop months after the procedure. These cracks allow bacteria to reach deep into the surrounding tissue, causing sharp pain when you bite down.
4. Broken dental tools
The tiny metal files used to clean out a root canal are extremely delicate. If a tool tip snaps off inside the tooth during treatment, or if the side of the tooth root is accidentally punctured, it can cause ongoing inflammation, tissue damage, and pain.
Under the GDC’s Standards for the Dental Team, if a file snaps off during treatment, the practitioner is under a strict legal and professional duty of candour to inform the patient immediately. Leaving a broken tool without informing the patient or attempting referral is a primary trigger for UK dental negligence claims.
5. Ongoing inflammation in the jawbone
In some cases, the surrounding bone and tissue at the tip of the tooth root stay inflamed even after the internal infection has been cleaned out. If the bone around the root struggles to heal properly, it can trigger a constant, dull ache or pain when eating.
Symptoms you shouldn’t ignore
Complications from a failed root canal rarely resolve on their own. You should book an appointment with a dental professional if you notice:
- Severe or throbbing pain when biting down or chewing
- Swelling, redness, or tenderness in the gums near the treated tooth
- A small bump or pimple-like spot on your gums (a sign of an abscess)
- An unpleasant taste or persistent bad breath coming from the area
- Pain that spreads to your jaw, neck, or ear
Could your pain be the result of dental negligence?
Root canals can sometimes fail even when your dentist did everything right. Dentists have a legal duty to perform treatments safely, accurately, and thoroughly.
Dental negligence during a root canal might occur if a dentist:
- Fails to take proper X-rays before treatment to check the shape and length of the roots
- Leaves a broken tool tip inside the tooth
- Fails to fill and seal the root spaces properly, leaving gaps for bacteria to grow
- Fails to protect the tooth with a hygienic rubber guard during treatment, allowing bacteria to enter
- Ignores clear signs of an ongoing infection during follow-up appointments
If your ongoing pain was caused by substandard dental treatment, you may be eligible to claim compensation. This can hopefully help cover the cost of corrective care and go a little way towards recognising the pain and suffering you have experienced.
To find out if you have a potential claim, read more about making root canal compensation claims or get in touch with our specialist dental negligence solicitors.
What should you do next?
If your root canal tooth is hurting months later, you should take the following steps:
- Get an independent dental assessment: Book an appointment with a dentist – or ideally a root canal specialist (an endodontist) – to get fresh X-rays or a detailed 3D scan.
- Request your dental records: Ask your dental practice for full copies of your treatment history, X-rays, clinical notes, and consent forms.
- Keep a symptom diary: Note down when the pain started, how severe it gets, any visible swelling, and details of any extra treatment you receive.
- Seek independent legal advice: If another dentist finds that your original treatment was carried out poorly, speak with a dedicated dental negligence solicitor to find out whether you may be eligible to claim compensation.