What are cavities?

Cavities or caries occur when the two outer layers of the tooth, the enamel and the dentine, become eroded. The enamel is the hard, white, outer layer of the tooth, while the dentine is the layer found just beneath that.

What causes cavities?

A number of bacteria normally live in the mouth. Some of these bacteria are responsible for converting the sugars and carbohydrates that we eat into acid. The bacteria and acid mix with food particles and our saliva to form plaque, a sticky film that coats our teeth.

The acid in the plaque can erode the enamel on our teeth and these erosions can get bigger over time. Eventually the acid in the plaque may get through to the dentine. Problems can arise here as underneath the dentine lies the pulp of the tooth. This is the part of the tooth that contains blood vessels and sensitive nerve fibres.

Damage to the pulp can lead to a number of problems: pain and swelling, infection, tooth abscess, even pulp death. Pulp damage usually leads to tooth extraction. In some cases, root canal treatment is required. (This is when the dying pulp is removed and replaced with an inert material). If you have a toothache, a cavity will more than likely be the cause of it.

What are the symptoms of a cavity?

If you have a cavity, you will be sensitive to hot, cold or sweet foods.

How can I prevent cavities?

There are a number of ways cavities can be prevented. Good oral hygiene is essential. Brushing your teeth daily helps to reduce acid plaque damage to teeth. However, this is not enough. Flossing is also essential in order to remove plaque from between teeth that brushing may have missed.

Brushing after meals is ideal. However if this is not possible, try eating something crunchy like an apple, as this helps sweep away food and plaque. Chewing gum after a meal can also help, as long as it is sugarless, of course.

Diet is important too. By reducing the amount of sugars we take in, we can reduce the amount of acid-producing bacteria in the mouth. Calcium, phosphorous and vitamins A, C, and D can aid strong enamel formation, so make sure these are included in your diet.

It is also important to try and reduce the number of snacks we eat between meals. After every snack acid attacks the teeth, therefore, if we eat snacks all day, our teeth will be attacked by acid all day. And of course, regular check-ups at the dentist are essential.

What if I already have a cavity?

If you already have a cavity, then you will more than likely end up getting a "filling" at the dentist.

Before putting in a filling, the dentist must first clean the cavity. The clean cavity is then "filled" to restore the tooth to its original shape and size. The most common type of filling is the easily recognisable silver filling (dental amalgam).

These fillings contain, amongst other things, a tiny amount of mercury. While some people have questioned the possible adverse effects of mercury in fillings, the actual amount used is less than the amount found in seafood.

In recent years, porcelain fillings have increased in popularity. While they are a more expensive option, the colour of the filling can be exactly matched to the colour of the tooth; therefore the filling isn’t noticeable like the silver one.

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