A guide to tooth decay & dental caries

Tooth decay, also known as dental caries, can result from the disintegration of tooth enamel because of bacterial infection of your teeth. These cavities can lead to the development of tiny holes in your teeth. Tooth caries are very common in children, but almost anybody can suffer from them.

Causes of tooth decay

Tooth decay is often the result of poor dental hygiene practices and poor diet. When you eat too many foods that contain starch and sugars, the harmless bacteria present in your mouth will begin to break down the carbohydrates in the food into acid. This acid will then coalesce with the bacteria and food debris to produce a white film, known as plaque. This plaque then proceeds to cover the surface of your teeth, and begins to eat away at the enamel. This is a slow process, and takes at least two years. When the enamel has been eroded, it causes the formation of a tiny hole or cavity on the surface of the enamel. Through these holes or cavities, the plaque can easily reach into the dentin, which is a softer material supporting the enamel. Because the dentin is softer than the enamel, it speeds up the process of decay. Soon, the bacteria and plaque will enter the pulp, or center of the tooth. This pulp consists of soft tissue, nerves and blood vessels. When the bacteria enter the pulp, the nerves become exposed, causing intense pain.

Tooth decay is generally seen in the molars and premolars situated at the back of the mouth, which you use to chew food with. Because of the shape of the molars, food debris can easily get stuck here, leading to the formation of plaque and dental cavities. These teeth are also harder to reach with a toothbrush, creating prime conditions for the accumulation of plaque and bacteria. Permanent teeth may be able to ward off tooth decay for a while, but as the process of decay continues, each layer of your tooth is eroded, disintegrating your tooth further.

Risk factors for tooth decay

There are several factors that have been found liked to tooth decay.

Certain foods and drinks expose your teeth to decay faster than others. Foods and drinks that are high in fermented carbohydrates have been found to cause greater amounts of plaque, thereby raising the risk of tooth decay. Fermentable carbohydrates include table sugar, raisins, honey, milk, dry fruits, bread and potato chips, which can stick to your teeth for a long time after being consumed. Candies, although sweet and sticky, don’t cause much damage to the teeth because they can be quickly cleaned by saliva. Potato chips fragments, however, stick stubbornly to your teeth, increasing the risk of tooth decay.

Constant snacking also affects the rate of tooth decay. When you frequently eat snacks and drink sugary sodas, the acid gets more time to attach to the surface of your teeth. These acids can remain on the teeth for hours, thereby causing erosion. This is the reason why parents are discouraged from giving babies bottles of milk or sweetened juice at bed time. Dentists advise giving a baby some water after eating and drinking, to wash away the affects of the sugary foods and drinks.

Poor dental hygiene
Poor oral hygiene practices also contribute to the development of carries. Brush at least twice a day, and even after every meal. Use a dental floss to remove any food debris from between your teeth.

Smoking can raise the risk of developing tooth decay because it decreases saliva production. Saliva is extremely important to keep teeth surfaces clean. Passive smoking too can increase the risk of dental decay in children.

Bottled water
The fluoride that‘s added to public water supply contains essential minerals that protect the teeth from decay. If you drink bottled water that contains no fluoride, you may miss out on the protective qualities of fluoride.

Older adults tend to suffer from tooth decay more than younger people. That’s because many adults retain their natural teeth, which can wear out over time, putting them at risk for tooth decay.

Recession of the gums
When your gums recede, plaque begins to form on the tooth root. The tooth root, under normal circumstances, is covered with cementum, but this coating can quickly disappear when the root is exposed, leading to decay.

Eating disorders
An eating disorder like anorexia and bulimia puts you at higher risk for tooth decay. This is because anorexia can decrease saliva production that’s so necessary for cleaning the teeth. Bulimia on the other hand, involves vomiting, which can expose the mouth and teeth to stomach acids.

Dry mouth
Saliva has many benefits in preventing tooth decay. It helps clean away food debris and plaque, and also contains minerals that help repair tooth decay in its early stages. Saliva can also inhibit the growth of bacteria that can disintegrate tooth enamel, leading to infections of the mouth. Lastly, saliva works to neutralize the effects of acids present in your mouth. When there is a decrease in saliva production, therefore, there is increased risk of tooth decay.

Dryness of the mouth can occur because of the use of certain drugs:

  • Anti-epileptic medicines and anti psychotic medicines.
  • Antihistamines.
  • Tricyclic anti-depressants.
  • Beta blockers that are used to treat heart conditions.
  • Radio therapy.

Weak dental fillings
Dental fillings can become weak and break down over the years, causing ideal conditions for the development of plaque and tooth decay.

GORD (Gastroesophageal Reflux Disease)
This is a digestive condition in which stomach acid backs up or reverses out of the stomach, and right into the throat or mouth. This acid can corrode the surfaces of the tooth, and wear away your teeth enamel.

Close contact
Many of the bacteria in the mouth responsible for tooth decay can be passed through personal contact, including sharing utensils or kissing.

Cancer treatment
Cancer patients who receive radiation therapy to their head or neck are at higher risk for developing cavities. That’s because radiation changes the saliva, causing more dangerous cavity-causing bacteria to thrive.

Symptoms of tooth decay

During the beginning stages of tooth decay, there may be very few symptoms. As the decay progresses, you may notice symptoms like:

  • Toothache.
  • Sharp pain while eating anything very cold, hot or sweet.
  • Increase sensitivity in your tooth.
  • Holes in your tooth.
  • Unpleasant breath.
  • Unpleasant taste in your mouth.
  • Appearance of brown, black or grey spots in your teeth.
  • Pain when you bite.
  • Puss around the tooth.

Diagnosis of tooth decay

A simple physical examination of your mouth should indicate tooth decay. If the decay is in a tooth that is difficult to examine, your dentist may recommend an X-ray, which can reveal the cavities.

Types of cavities

Upon an examination, your dentist will be able to pinpoint what kind of cavity you are suffering from.

Smooth-surface cavities
Here, the cavities are found on the flat surface of the tooth. These are most commonly found on the teeth at the side of the mouth. These are generally the easiest kind of cavities to treat.

Pit and fissure decay
These cavities occur in the pits and grooves of your back teeth. If you don’t consult your dentist immediately, this kind of decay can progress very rapidly.

Root cavities
These cavities are more common in older people who have receding gums. The decay here occurs at the root of the front of the tooth.

Treatment for tooth decay

Teeth cavities can be prevented through the use of fluoride. In the early stages of cavity development, a fluoride treatment can restore enamel preventing from decay.  Fluoride treatment can come in a gel or liquid form, or as a varnish that can be brushed onto your teeth. Fluoride not only repairs the tooth enamel, but also removes bacteria and plaque from your mouth. Fluoride-containing products like toothpaste, mouthwash and gel contain varying amounts of fluoride, but a professional fluoride treatment recommended by your dentist is the most effective source.

When a cavity has progressed considerably, a dentist will have to replace the decayed portions of the teeth with fillings. He will remove the decayed portion by using a drill, and then fill the gap using a variety of materials like composite resins, porcelains, silver amalgam fillings, etc.

If a tooth has been extensively decayed, your dentist may recommend a crown instead of fillings. Fillings may not be able to restore the tooth, and so your dentist will drill away the decayed portion, and fit a crown over the remaining section of the tooth. Crowns can be made of porcelain or gold.

Root canal treatment
When the tooth decay is extremely severe and has reached the inner pulp of the tooth, your dentist will recommend a root canal treatment. Here, the pulp is removed, and replaced with an artificial pulp. Root canal treatment used to be a painful procedure, but these days, modern dental technologies have almost completely eliminated the pain.

A severely decayed tooth will have to be removed entirely to prevent the infection from spreading. Extracting a tooth can lead to the other teeth shifting or moving, affecting the shape of the mouth. This can be corrected by replacing the extracted tooth with a dental implant.


  • If tooth decay is ignored, the bacteria can begin to attack the gums, causing gum diseases like gingivitis and periodontitis.
  • Teeth may break, or may have to be extracted to stop the infection from spreading, and this can lead to deterioration in appearance and loss of confidence.
  • If the pain is severe, there may be difficulty in eating and chewing, which can lead to loss of weight.
  • In cases of extreme decay, swelling known as dental abscesses filled with pus may begin to develop, and these can cause intense pain.
  • If abscesses are left untreated, there can be even be life-threatening infections.

Prevention of tooth decay

A few basic easy-to-follow precautions to keep tooth decay at bay:

  • Practising good dental hygiene can prevent cavities to a large extent. Remember to brush twice a day using a fluoride toothpaste. Use dental floss or an interdental cleaner to clean the area between your teeth.
  • Use a fluoridated mouth rinse to keep the risk of tooth decay at bay.
  • Get your teeth checked up regularly by your dentist to catch potential problems in the early stages
  • Replace your toothbrush regularly, at least once every 6 months.
  • Consider applying dental sealants to protect the grooves in the teeth. Sealants can be used by both children as well as adults.
  • Drink tap water. Public water contains fluoride that reduces the risk of tooth decay. Bottled water, on the other hand, contains no fluoride.
  • Avoid starchy, sugary foods. Chips, candy and other foods that can get stuck in the grooves of your teeth must be avoided. Instead, eat healthy foods like fresh foods and vegetables, plus sugarless coffee and tea to help wash away the food debris.
  • Ask your dentist for a fluoride treatment if you are not getting enough fluoride through natural sources. Your dentist may recommend concentrated fluoride applications.
  • Don’t eat and drink constantly. Avoid snacking and sipping at regular intervals.
  • Ask your dentist about special antibacterial treatments that can reduce the amount of harmful bacteria in your teeth.