Why Does My Tooth Hurt When I Bite Down?
You bite into something and feel a sudden, sharp pain in one tooth. It might disappear as soon as you stop chewing, or perhaps there's a dull ache every time your teeth come together.
What's particularly frustrating is that the tooth can look completely normal. No obvious hole, no broken filling and no discomfort at all until you put pressure on it. This can make it difficult to understand what's going wrong, particularly if you can eat certain foods without any trouble.
Pain when biting down can be caused by a cracked tooth, an inflamed ligament around the tooth, a damaged filling, decay or an infection around the root. The type of pain, when it occurs and whether it lingers afterwards can all help a dentist narrow down the cause.
Why does my tooth hurt when I put pressure on it?
Your teeth might feel firmly fixed in place, but they're actually supported by a network of tiny fibres called the periodontal ligament. This acts as a shock absorber, helping your teeth cope with the considerable forces involved in biting and chewing.
When the ligament becomes inflamed, pressure that would ordinarily go unnoticed can become uncomfortable. However, the source of the pain isn't necessarily the ligament itself. Biting can cause a small crack in the tooth to flex, put pressure on weakened tooth structure or aggravate inflammation within the tooth.
One of the most useful clues is whether the pain occurs as you bite down, when you release the pressure or throughout the entire movement. These differences can help guide an examination, although the symptoms alone aren't enough to establish a diagnosis.
Common causes of tooth pain when biting
1. A cracked tooth
A cracked tooth is a common explanation for sharp, intermittent pain when chewing. Unlike a tooth that's visibly chipped or broken, a crack can be extremely difficult to spot. It may run through the chewing surface without causing any obvious damage to the outside of the tooth.
As you bite down, the pressure can cause the sections on either side of the crack to move very slightly, irritating the sensitive tissues inside. This helps explain why chewing certain foods might be painful while others cause no discomfort. You may also notice a sharp sensation when releasing your bite, or increased sensitivity to hot and cold temperatures.
The treatment depends on how far the crack extends and which parts of the tooth are affected. A crown or another restoration may be able to protect the tooth and prevent further damage, although deeper cracks can be more difficult to treat.
If these symptoms sound familiar, our guide to cracked tooth syndrome explains how dentists investigate cracks that aren't immediately visible and what treatment options may be available.
2. A filling that's damaged or too high
If you've recently had a filling and the tooth now hurts when you chew, the restoration itself could be responsible. Even a small difference in height can affect the way your teeth meet, leaving the treated tooth absorbing more pressure than it should.
Over time, this additional force can irritate the periodontal ligament and make the tooth tender when biting. A dentist can check how your upper and lower teeth come together and, if necessary, make a small adjustment to the filling.
Older fillings can cause problems too. Restorations may loosen, fracture or develop decay around their edges, particularly after years of chewing forces. If discomfort is concentrated around a tooth with an existing filling, it's worth having it examined rather than assuming the filling is still intact.
3. Inflammation around the tooth root
Pain when biting can also originate from the tissues surrounding the root of a tooth. Infection, injury and excessive biting pressure can all cause inflammation in this area, making the tooth tender whenever force is applied.
You might notice that the tooth feels slightly raised, as though it's making contact before the others, or find yourself instinctively chewing on the opposite side of your mouth. The discomfort can range from mild tenderness to pain that makes eating difficult.
Because the problem may be occurring beneath the gumline, there isn't always anything visible to explain it. A dentist will usually examine the tooth, assess its response to pressure and consider whether an X-ray is needed to investigate the surrounding bone and root.
4. Tooth decay
We tend to associate cavities with sensitivity to sweet foods or cold drinks, but decay can also make a tooth painful when chewing. As it progresses through the enamel and into the softer dentine beneath, it can weaken the tooth structure and irritate the tissues inside.
Decay isn't necessarily visible when you look in the mirror, either. It can develop between neighbouring teeth or beneath an existing restoration, where changes may go unnoticed until symptoms begin.
If the tooth has become structurally weakened, biting pressure can make the discomfort more pronounced. The earlier decay is identified, the greater the opportunity to treat it before more extensive damage occurs.
5. Teeth grinding or clenching
Your teeth can experience considerable pressure even when you're not eating. Grinding and clenching, particularly during sleep, place repeated forces on the teeth and their supporting ligaments, potentially leaving them tender or uncomfortable.
People who grind their teeth may wake with aching jaw muscles, headaches or a feeling that several teeth are sensitive when they bite. The pressure isn't always distributed evenly, so one tooth may become more uncomfortable than its neighbours.
If grinding is contributing to the problem, treatment may involve addressing factors that increase the strain on your teeth. Depending on the circumstances, your dentist might recommend a custom-made night guard to help protect them from further damage.
Why does my tooth hurt when I release my bite?
Pain on releasing biting pressure is a particularly useful symptom to mention to your dentist because it can be associated with a cracked tooth.
When you bite, the sections of a cracked tooth may move slightly apart under pressure. As you release your bite, they return towards their original position, potentially irritating the sensitive tissues inside the tooth. The result can be a sudden, sharp pain that disappears almost as quickly as it arrives.
This doesn't automatically mean you have a cracked tooth, but it does give your dentist something specific to investigate. They may use a small biting instrument to apply pressure to individual cusps, the raised areas on the chewing surface, to see whether a particular part of the tooth reproduces the pain.
Cracks can be difficult to identify, especially when they're very fine or extend in a direction that doesn't show clearly on an X-ray. Your description of exactly when the pain occurs can therefore be just as valuable as the examination itself.
Why does my tooth hurt when I bite but not at any other time?
One of the more puzzling aspects of biting pain is that the affected tooth may feel perfectly comfortable for most of the day. You can talk, drink and brush your teeth without noticing anything unusual, only to experience a sharp pain when chewing.
The explanation often lies in the way pressure affects the tooth. A small crack may remain relatively undisturbed until biting forces cause it to flex, while an inflamed periodontal ligament can feel comfortable at rest but painful when compressed.
The fact that a tooth only hurts under pressure doesn't necessarily mean the underlying problem is minor. In particular, recurring pain in the same tooth deserves investigation, even if it disappears as soon as you finish eating.
Can tooth pain when biting go away on its own?
The answer depends on what's causing it. Mild inflammation following excessive biting pressure or recent dental treatment may settle as the affected tissues recover, especially once the source of irritation has been addressed.
However, an improvement in symptoms doesn't always mean the problem has resolved. A cracked tooth cannot repair itself, and an infection around the root generally needs dental treatment. Pain may also fluctuate, making a problem appear to have disappeared before it returns.
If you find yourself repeatedly avoiding a particular tooth, changing how you chew or noticing that the pain is becoming more frequent, it's sensible to arrange an examination. Identifying the cause early may help prevent further damage and give you more options for preserving the tooth.
What can I do if my tooth hurts when chewing?
Until you can have the tooth examined, the most useful thing you can do is reduce the pressure being placed on it. Choose softer foods, chew on the opposite side where comfortable and avoid biting directly into hard foods such as nuts, crusty bread or ice.
Continue brushing twice daily with fluoride toothpaste and cleaning between your teeth, taking care around any particularly tender areas. If you need pain relief, paracetamol or ibuprofen may help, provided they're suitable for you. Follow the instructions on the packaging or speak to a pharmacist if you're unsure.
If the problem started after a filling and your bite feels uneven, resist the temptation to adjust anything yourself. Even a minor alteration to a restoration needs to be carried out carefully to avoid creating further problems.
When should I see a dentist?
Recurring pain when biting is worth investigating, even if the tooth looks completely normal and the discomfort only lasts a few seconds. A dentist can check the condition of the tooth, assess your bite and use pressure and temperature tests to help identify the source of the pain.
Depending on the findings, X-rays may also be needed. These can reveal decay, changes around the roots and other problems that aren't visible during a routine examination, although very fine cracks may not appear clearly.
If the pain becomes severe, prevents you from eating comfortably or is accompanied by swelling, fever or signs of infection, seek urgent dental advice. Significant swelling that affects your ability to breathe or swallow requires emergency medical attention.
How is tooth pain when biting treated?
There's no single treatment for pain when chewing because the underlying causes are so varied. If a filling is slightly too high, a straightforward adjustment may resolve the problem. A damaged restoration might need repairing or replacing, while a cracked tooth could require a crown to protect the remaining structure.
Where the nerve inside the tooth has become irreversibly inflamed or infected, root canal treatment may be necessary to remove the affected tissue and preserve the tooth. If grinding is placing excessive strain on your teeth, managing those forces may form part of the treatment plan.
In more severe cases, particularly where a crack extends too far beneath the gumline, the tooth may not be restorable and extraction could be necessary. However, pain when biting certainly doesn't mean you're going to lose the tooth. The appropriate treatment can only be determined once the cause has been identified.
Don't ignore pain that only happens when you bite
It's easy to dismiss a tooth that only hurts during the occasional meal, particularly when you can still eat most foods without difficulty. But pain triggered by pressure can be an early indication of a problem that isn't immediately visible, from a small crack or uneven filling to inflammation around the root.
If you've noticed a particular tooth becoming uncomfortable when you chew, it's worth finding out why rather than waiting for the symptoms to become more persistent.
You can send Dr Zaeem Jafri a photo and a description of your symptoms through Nova Smiles' free online dental assessment. He can offer an initial opinion on what might be worth investigating, although diagnosing biting pain generally requires an in-person examination and may involve X-rays. There's no obligation to proceed with treatment.
Reviewed by Dr Zaeem Jafri BDS, Nova Smiles
