What Causes Tooth Decay?

Tooth Decay

Tooth decay is one of the most common oral health problems, affecting people of all ages across the globe. It can lead to a range of problems, from simple cavities, through to more severe issues with wide-ranging consequences.

What causes tooth decay? What are the consequences? And how can you prevent it? Find out below.


What Can Cause Tooth Decay?

It’s a common myth that foods such as sugar rot teeth. The reality is that tooth decay is caused by acid-producing bacteria in the mouth.

When these bacteria are left on the teeth long enough, or grow large enough, the acid they produce gradually breaks down the enamel. After enough time, this forms cavities in the enamel that expose the underlying layers of the tooth.

That said, sugar still plays a roll in tooth decay. We recently published information on bad foods for your teeth. Bacteria eats sugar and starch left in food particles on the teeth and turns it into acid. The more sugary or starchy foods you eat, the more fuel you provide for the bacteria to grow.

The most common places to get tooth decay are on the biting surfaces of molars, as these are usually the hardest to remove food particles from without thorough brushing. This is one of the reasons children and the elderly are more susceptible to tooth decay, as they have a harder time cleaning their teeth than adults. Another factor is that enamel is softer in children and the elderly, making it easier to decay.

How to Prevent Tooth Decay

The easiest way to prevent tooth decay is brush and floss your teeth regularly.

Regular cleaning of the teeth clears away food particles that bacteria feed on, preventing them from over-producing acid that decays the enamel. Flossing in particular helps to remove difficult to reach particles stuck between teeth that often lead to decay.

In children, dental sealants are a popular option to prevent decay. Sealants are a clear covering that go over the teeth to prevent food sticking directly to the tooth, thus preventing bacteria building up and decaying the tooth itself.


Signs of Tooth Decay

Early stages of tooth decay, much like the early stages of gum disease, may have no discernible symptoms. As the decay progresses, it will become more noticeable. Possible symptoms include:

  • Toothache
  • Tooth sensitivity
  • Pain when eating or drinking hot, cold, or sweet foods
  • Visible holes and pits in the teeth
  • Brown, black or white staining on the surface of a tooth



Cavities are patches of permanent damage in the enamel of a tooth. They take the form of small pits or depressions in the tooth surface.

Cavities are one of the most common health problems in the world — not just in terms of oral health. They’re especially common in children, and often thought of as a childhood problem, but really they can affect anyone with teeth at any time.

Tooth enamel cannot be restored once it’s lost. After a cavity has formed, the only solution is to close it with a filling.

If cavities aren’t caught and filled early, they will continue to grow. Possible outcomes include:

  • Exposing the interior of the tooth to infection.
  • Weakening the integrity of the tooth enough to chip or crack under pressure.

An infection inside a tooth can have major consequences. The very inner material of a tooth is called the pulp, and it surrounds the tooth nerve. Infection of the inner pulp can cause inflammation and extreme pain. The dentist may have to perform a root canal, or if the tooth is too far gone, extract the tooth completely.

Infections within the tooth also introduce the risk of bacteria entering the bloodstream. This in turn can increase the risk of other problems within the body, such as a raised risk of cardiovascular disease.

Chipped and cracked teeth also risk infection to the inner tissue of a tooth. Treatment for a chipped or cracked tooth usually involves either a dental crown, or the use of an inlay or onlay to restore the biting surface of a tooth.


The Importance of Regular Dental Checks

Regular dental appointments can help to catch tooth decay in its earliest stages, even before permanent damage has been done. Your dentist or oral hygienist will specifically look for signs of tooth decay during a routine check and clean.

Catching decay early allows you to save yourself from pain, discomfort and infection, while also keeping your teeth healthy and strong for longer.