Tooth Decay

What’s tooth decay?

Tooth decay happens when the enamel and dentine of a tooth are softened by acid attacks, producing a cavity (hole).

What causes tooth decay?

It’s caused by plaque acids that gradually dissolve the enamel and dentine to create a cavity. Dental decay is the same as tooth decay and is also known as ‘dental caries’. Decay damages your teeth and can lead to the tooth needing to be filled or even removed.

What’s enamel?

Enamel is the hard protective outer coating of the tooth and is the hardest part of the body. It doesn’t contain any nerves or blood vessels and is not sensitive to pain.

What’s dentine?

Dentine lies under the enamel, forming most of the tooth and can be very sensitive to pain. Dentine covers the central pulp of the tooth.

What’s the pulp?

The pulp is a soft tissue in the middle of the tooth that contains blood vessels and nerves.

What’s plaque?

Plaque is a thin, sticky film that keeps forming on your teeth. It contains many types of bacteria.

Why do my teeth decay?

Decay happens when sugars in food and drinks react with the bacteria and plaque, forming acids. Every time you eat or drink anything containing sugars, the bacteria reacts with it to form acid. These acids attack the teeth and start to dissolve the enamel. The attacks can last for an hour after eating or drinking, before natural salts in your saliva cause the enamel to ‘remineralise’ and harden again.

It’s not just sugars that are harmful – other types of carbohydrate foods and drinks react with plaque and form acid (these are the ‘fermentable’ carbohydrates such as the ‘hidden sugars’ that can be added to processed food, natural sugars like those found in fruit, and cooked starches).

Snacking on sugary or acidic food and drink can increase the risk of decay, as the teeth come under constant attack and don’t have time to recover. So it’s important not to keep snacking on sugary foods or drinks throughout the day.

What are the signs of tooth decay?

In the early stages of tooth decay, there are no symptoms but your dentist may be able to spot an early cavity when they examine or x-ray your teeth. This is why you should visit your dentist regularly, as small cavities are much easier to treat than advanced decay.

What happens if I have a cavity?

Once the cavity’s reached the dentine your tooth may become sensitive, particularly with sweet foods and drinks, and acidic or hot foods.

As the decay gets near the dental pulp you may suffer from toothache. If the toothache is brought on by hot or sweet foods this may only last a few seconds. As the decay gets closer to the dental pulp the pain may last longer and you may need to take painkillers like paracetamol or ibuprofen to control the pain. You must visit your dentist asap as the tooth is dying and you may develop a dental abscess if it’s not treated.

What happens if I don’t get it treated early?

Toothache is a sign that you should visit a dentist immediately, as it’s a warning that something’s wrong. If you don’t do anything, it usually makes matters worse, and you may lose a tooth that could have been saved.

What areas of my teeth are more likely to decay?

The biting surfaces of the teeth and the surfaces between the teeth are most likely to decay, as food and plaque can become stuck in these areas.

What treatment will I need?

If the decay’s not too serious, the dentist will remove all the decay and restore the tooth with a filling. Sometimes the nerve in the middle of the tooth can be damaged. If so the dentist will need to carry out root canal treatment by removing the nerve and restoring the tooth with a filling or a crown. If the tooth is so badly decayed that it cannot be restored, the only option may be to extract the tooth.

Will I always need a filling?

No. In the very early stages of decay, your dentist may apply a fluoride varnish onto the area. This can help stop further decay and ‘remineralise’ the tooth. However, it’s important to continue with good oral hygiene, using fluoride toothpaste to prevent further decay.


What can I do to prevent decay?

The best way to prevent tooth decay is by brushing your teeth thoroughly twice a day with fluoride toothpaste, making sure that you brush the inner, outer and biting surfaces of your teeth. Using dental floss, tape or interdental aids also helps remove plaque and food from between your teeth and gumline. These are areas a toothbrush can’t reach.

Is there anything I can do to protect my teeth against decay?

As the adult molars appear, and if the tooth is free of decay, a ‘fissure sealant’ can be used to protect the tooth. The sealant is a plastic coating that fills all the little crevices in the tooth surface, creating a flat surface that’s easier to clean. This is called a ‘pit and fissure sealant’. Adults can also have this treatment if the teeth are free of decay.

Is there anything else I can do?

Visit your dentist regularly, as often as they recommend, and have sugary acidic food and drinks less often. Avoid snacking between meals as this limits the times your teeth are under attack from acids. Chewing sugar-free gum for ten minutes after a meal can help your mouth produce more saliva, which helps to neutralise any acids which have been formed.

How can my dentist and hygienist help me prevent decay?

Your dentist or hygienist will show you what areas you need to take most care of when cleaning. They’ll also show you how to brush and floss correctly.

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