What is tooth decay?

Tooth decay, also known as dental decay or dental caries, is when your teeth are eroded by plaque. Over time, the hard protective outer layer of your teeth wears away, exposing the soft and sensitive middle of your teeth to damage.

Although levels of tooth decay have decreased in many places as a result of fluoride in the water supply, it is still a common problem.

Plaque

A thick, sticky, soft mass that adheres to the surface of the teeth and gums and is the primary cause of tooth decay. It is composed of bacteria, food particles and mucin derived from the saliva. It cannot be rinsed off with the flow of water or saliva.

Fluoride

A mineral commonly added to water supplies or toothpaste to reduce tooth decay.

Causes

Tooth decay is caused by plaque, which is created when the bacteria in your mouth combine with food particles and saliva. Bacteria in plaque produce acid from carbohydrates found in food, such as sugary foods and drinks. The acid breaks down the hard outer layer of your teeth, eventually damaging the soft middle part.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Carbohydrates

One of the three macronutrients in foods that supply the body with energy. Examples include sugars, starches and cellulose.

Plaque

A thick, sticky, soft mass that adheres to the surface of the teeth and gums and is the primary cause of tooth decay. It is composed of bacteria, food particles and mucin derived from the saliva. It cannot be rinsed off with the flow of water or saliva.

Saliva

The clear watery fluid secreted into the mouth by salivary glands, which aids chewing, swallowing and digestion.

Risk factors

Risk factors for tooth decay include:

  • Location - tooth decay is most common in the teeth at the back of your mouth because they have more grooves than your front teeth, making them more likely to collect food and harder to keep clean;
  • 'Sticky' food and drink - food that gets stuck on your teeth or between them, such as hard lollies, biscuits, milk or ice-cream, causes more damage than food easily washed away by your saliva;
  • Food and drink high in sugar cause the bacteria in plaque to produce more acid, which damages your teeth;
  • Frequent snacking between meals;
  • Inadequate brushing of your teeth;
  • Lack of fluoride - fluoride is a mineral that helps prevent tooth decay and is added to some, but not all, treated water supplies;
  • Age - dental decay is more common in younger or older people;
  • Dry mouth - saliva helps protect your teeth by neutralising the acid in your mouth. A dry mouth is a sign you are not producing enough saliva;
  • Heartburn - acid reflux can enter your mouth and erode your tooth enamel, and;
  • Eating disorders - both anorexia and bulimia result in recurrent vomiting, which can erode tooth enamel.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Plaque

A thick, sticky, soft mass that adheres to the surface of the teeth and gums and is the primary cause of tooth decay. It is composed of bacteria, food particles and mucin derived from the saliva. It cannot be rinsed off with the flow of water or saliva.

Saliva

The clear watery fluid secreted into the mouth by salivary glands, which aids chewing, swallowing and digestion.

Fluoride

A mineral commonly added to water supplies or toothpaste to reduce tooth decay.

Enamel

The hard, white outer coating of the tooth.

Signs and symptoms

Tooth decay often has no symptoms until it becomes advanced, which is why regular visits to your dentist are a good idea. As tooth decay gets worse, symptoms include:

  • Toothache or sensitivity to hot, cold or sweet foods and drinks;
  • Bad breath;
  • Grey, brown or black spots on your teeth;
  • A bad taste in your mouth, and;
  • Visible holes or pitting in the teeth.

Methods for diagnosis

The majority of cavities resulting from tooth decay are identified during a routine dental check-up. A dental examination can reveal that the surface of your teeth is soft, indicating that the hard outer layer has been worn away. An X-ray of your teeth can also reveal the extent of cavities.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Types of treatment

If caught in the early stages, your dentist can apply a fluoride varnish to your teeth to stop them from decaying further. However, if the outer layer of your teeth has worn away, resulting in a cavity, your dentist will have to remove the decay and create a filling. If the nerves at the roots of any of your teeth have been damaged, you may also require root canal treatment. Any teeth that are so badly damaged they cannot be fixed may need to be removed.

Fluoride

A mineral commonly added to water supplies or toothpaste to reduce tooth decay.

Potential complications

Complications of tooth decay include:

  • Toothache and sensitive teeth;
  • Fractured teeth;
  • Abscess formation, and;
  • An inability to bite with an affected tooth or teeth.

Abscess

A swollen area of tissue containing a build-up of pus.

Prognosis

Treatment is more successful and less expensive the earlier tooth decay is caught. If the decay is severe, then teeth may need to be removed.

Prevention

You can help prevent tooth decay by practising good oral hygiene in the following ways:

  • Brushing your teeth at least twice a day for 2-3 minutes each time;
  • Using a toothpaste containing fluoride when you brush;
  • Flossing at least once a day;
  • Using mouthwash before brushing. If it is used after, it can wash away the protective residual toothpaste, and;
  • Cutting down on sugary food and snacks.
Brushing teeth is an important routine in a child's life.Daily brushing of teeth can prevent development of tooth decay.  

Fluoride

A mineral commonly added to water supplies or toothpaste to reduce tooth decay.