The top 10 causes of dental pain

Andrew Bain
26th Aug 2023

  • Tooth decay (dental caries)

  • Dental or Periodontal Abscess

  • Acute gum disease

  • Exposed root surface

  • Cracked tooth

  • Cracked/lost filling

  • Recent dental work

  • Infection around an erupting tooth - pericoronitis

  • Food trapping

  • Sinusitis - can mimic dental pain

Tooth Decay

Tooth decay (dental caries) is the most common infective disease worldwide. It is the dissolving away of hard tooth tissue - enamel, dentine and cementum by acid generated by bacteria in dental plaque. For decay to set in we need 3 things: Sugars in the diet, dental Plaque (especially the more acid producing types such as Streptococcus mutans, Streptococcus sobrinus, and lactobacilli) and time.

Every time we eat sugar the bacteria in our plaque metabolise it and the surface of the teeth are exposed to the acidic by-product of their metabolism. However our saliva quite quickly washes away the acid and reduces its acidity through buffering.

So to prevent decay we need to:

1. Clean our teeth effectively to reduce the plaque so they cannot produce acid

2. Eat less sugar - the FREQUENCY is the most important factor to allow the saliva time to neutralise the plaque acid.

3. Use fluoride based toothpaste and sometimes mouthwashes to strengthen the teeth against attack, and combat the plaque bacteria

Medications, diseases or treatment that affect the amount of saliva in your mouth can hugely increase the risk of dental decay.

Tooth decay causes pain due to inflammation in the dental pulp stimulating the nerve - pulpitis. Generally the closer the decay gets to the nerve the more serious the problem becomes.

See our pages on Reversible pulpitis and irreversible pulpitis to get some specific advice on pain relief while waiting for an appointment. Once the decay has reached the dentine, the tooth requires a filling or, if it has infected the nerve, a root canal treatment will be required to save the tooth.


An abscess is either the result of tooth decay once it breaches the nerve or it can also be caused by gum disease. The tooth has become infected and the source of the infection needs to be removed. This means either a root canal treatment to remove the infected nerve or an extraction to remove the whole tooth. While dentists stagger back to work it may be difficult to get a root canal treatment done and home management of an abscess is not easy. See our pages on acute periapical abscess and acute periodontal abscess for some ways to attempt to alleviate symptoms until an appointment can be made.

Acute gum disease

Gum disease generally is not a terribly painful condition, sometimes a patient can have very advanced gum disease and not be aware of it. However if the gum disease becomes acute then it can be painful. Typically this involves angry red gums, bleeding, bad taste, swelling etc. The most painful acute gum condition is Acute Ulcerative Gingivitis. Home oral hygiene methods and over the counter remedies and gels can be very effective in managing symptoms before you are able to visit the hygienist for more thorough cleaning.

Exposed Root Surface

Root surfaces are usually exposed due to recession of the gums and this can cause Dentine Hypersensitivity. This is most commonly seen between the ages of 20-50 with a peak between 30-39. This is characterised by sensitivity and pain, usually in response to cold things. But it can also be brought on by heat, touch (fingernail or dental probe) or sugar. The pain is very short lived and usually goes as soon as the stimulus is removed. This form of toothache can be effectively managed by sensitive toothpastes which have improved dramatically in recent years. See our Dentine Hypersensitivity page for more details and advice. It is important however to have a full diagnosis as the symptoms of dentine hypersensitivity can be similar to pulpitis caused by tooth decay.

Cracked Tooth

Cracks in teeth come in all sorts of shapes and sizes. Teeth can crack due to trauma or sports injury, they can crack because they are weakened by previous treatment or they can crack due to a serious tooth grinding habit (bruxism). All of these types of fracture can, but not always, cause toothache. A tooth hit by a cricket ball can expose the nerve of the tooth and this is clearly a dental emergency and needs prompt dental attention - Complicated Tooth Fracture. However a small fracture around an existing filling may simply cause mild sensitivity and this may be managed by sensitive toothpastes or DIY temporary filling materials until you can be seen for treatment. Again it is important to get a full diagnosis. There is another type of cracked tooth which can be hard to diagnose and mange - Cracked Tooth Syndrome. This is when the tooth has a hairline fracture which is not visible to you and often not even to the dentist. Cracked tooth syndrome tends to affect teeth which get a lot of wear and tear and those that have had previous work done to them. If your tooth has a suspected fracture like this then do try to avoid it as much as possible as it is the pressure of biting (and releasing from biting) that causes the pain and can worsen the fracture.

Treatment for this is best carried out as soon as possible to avoid the crack extending down to the nerve of the tooth. See Cracked Tooth Syndrome for more information.

Cracked/Lost Filling

Like with a cracked tooth this can range from losing a small corner of a filling to a whacking great hole extending towards the nerve of the tooth. Temporary DIY filling kits can be useful in the short term but care must be taken to thoroughly clean the tooth first. Sensitive toothpastes can also help keep a tooth less sensitive while waiting for a more permanent fix.

Recent dental work

Recent dental work can cause toothache in some cases. A filling can often cause some sensitivity for a few days afterwards and sometimes for longer. This is much more likely with deeper fillings when they extend towards the nerve of the tooth. The majority of fillings placed nowadays are white fillings (composite fillings). These fillings can sometimes cause more sensitivity than the more traditional silver amalgam fillings. The reason for this is that they bond to the tooth and then shrink when they harden. This means they can create tension and sometimes fractures within the tooth. Improvements in the materials and in dentists' techniques means this is less of an issue than it used to be.

If the filling was very close to the nerve or even if the nerve was exposed during the filling treatment, then there is a chance that the tooth could develop a fully blown pulpitis and the nerve may get infected.

Another more serious toothache that can occur after dental treatment is dry socket. This is a localised inflammation and exposure of the bone in the site of a recent extraction. For more information on this see our Dry Socket page

Infection around an erupting tooth

Pericoronitis is a common cause of toothache in young adults who have otherwise no dental issues. It is caused by inflammation and infection of the gum around an erupting tooth - most commonly the lower wisdom tooth. This can sometimes cause severe dental pain, swelling, bad taste, limited mouth opening and local lymph gland involvement. It can sometimes be treated from home using salty mouthrinses, chlorhexidine gels and pain killers. However if the infection is too great, swelling sets in and the lymph glands become involved then you might need some antibiotics. See our page on Pericoronitis for more information.

Food trapping

Food trapping between the teeth can be an extremely annoying problem and in some cases can be really quite painful. It can push the teeth apart irritating the periodontal ligament around the tooth roots and the gums. Teeth shape has evolved to enable a good contact between them to prevent food trapping however there are a number of reasons why these contact points may not be effective:

1. Tooth wear

2. Inadequately shaped fillings or crown

3. Gum and bone recession creating space

4. Drifting of teeth

At home all you can really do is keep the area as clean as possible and clean out any trapped food with floss, interdental brushes, toothpicks etc. Your dentist will see which of the above reasons is causing the trap and try to remedy the situation permanently.


If the toothache is poorly localised, in upper back teeth, made worse by bending down to tie your shoelaces and you have had a recent cold or ongoing sinus issues then there is a possible that the toothache has nothing to do with the teeth.

The roots of the upper molars lie very close to the maxillary sinus and the pain can really seem like it is coming from them. Many a dental student has been told the anecdote of patients having a number of teeth extracted for no reason. Whether this is true or not who knows but it is certainly something to bear in mind when diagnosing toothache. See our page on sinusitis for more information.

Other causes of pain

The conditions above cover the most common causes of tooth pain but there are many other conditions that can cause pain in the mouth which are beyond the scope of this blog post. Soft tissue abnormalities in the mouth, the temporomandibular joint disorders (TMD), bone disorders, auto-immune conditions, drug hypersensitivities and oral manifestations of other disease are all big topics which will be covered in future Ouch blog post.


Toothache can be extremely miserable, the nerves inside the tooth can become very inflamed and the hardness of the enamel and dentine means that this inflammation has nowhere to go. Many poets and writers through the ages attest to the misery of tooth ache.

A toothache, or a violent passion, is not necessarily diminished by our knowledge of its causes, its character, its importance or insignificance. - TS Eliot

Most causes of toothache do require active treatment by a dental professional and luckily modern treatment methods, anaesthetics and dentists training means that problems can be solved with little or no discomfort.

However in these times of uncertainty the provision of dental care is going to be very different.

1. Appointments will take longer due to new guidelines, so fewer patients can be seen.

2. The cost of safely providing treatment will increase dramatically

3. The experience going to the practice and receiving treatment may feel very alien

Some people will think that these new measures are overkill and unnecessary, others will feel that the high risk nature of the work that dentists do - close face to face contact - means that the measures are not strict enough and will stay away.

The truth is that everyone is trying to do their best in a very complex and new situation. There are so many unknowns but rest assured dentists will be doing their best to help their patients as much as possible.

If you are unable to get an appointment for a while or if you do not want to go to the dentist until things have calmed down then we hope that OUCH can help you.

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