Tooth Decay

Tooth decay is a common degenerative oral health condition that results in the erosion of tooth enamel. The foods we eat contain sugars and starches. When combined with the bacteria that exists in our mouths, the result is plaque, a sticky substance that forms on teeth. Plaque produces acids that damage the surface of the teeth, resulting in holes that are called dental caries, or cavities. The National Institutes of Health reports that 92% of adults aged 20 to 64 have had at least one cavity.


Cavities are holes in teeth resulting from tooth decay and can affect people of all ages. As they are most often tied to poor dental hygiene habits, they tend to be most common in children who are still learning the proper way to brush and floss. However, adults can get cavities as well. New cavities can form around the edges of areas of the tooth where previous cavities were filled in childhood, and receding gums from periodontal disease can expose lower portions of the teeth which do not have enamel and were previously protected from decay by the gums.

While tooth decay typically starts with the enamel of the tooth, it can affect all of the layers. The enamel is the hard outer surface of the tooth, followed by the dentin in the middle, and, lastly, the pulp, which contains the blood supply and nerve endings of the tooth. A cavity can take around three years to form in the enamel but will progress much faster through the softer inner layers of the tooth. Cavities do not cause any pain when they are in the enamel of the tooth, so without regular dental exams, it’s possible for them to go unnoticed until they have grown deeper and more severe.

Cavities are usually categorized by what part of the tooth they develop on and the extent of the decay. Cavity types include:

Smooth surface

These cavities form on the smooth surfaces of the teeth and are most often found in the spaces between teeth where toothbrushes have trouble reaching. Flossing and regular professional cleanings are the best way to prevent these from forming.

Pit and fissure

These cavities form on the tops of molars, in the crevices of chewing surfaces where food and plaque can be harder to remove. They tend to be more of a problem for people who don’t brush as often as they should, or those with poor brushing technique. Dental sealants are a good preventative measure against these types of cavities, as they can fill in the deeper areas and make it easier to keep the tops of the teeth clean.

Root decay

The hard enamel of teeth takes the longest to be affected by dental decay, but as we grow older, we are more susceptible to periodontal disease and gum recession. This exposes the softer dentin layer that was previously protected beneath the gum line. Root cavities are the result of tooth decay forming on these portions of the tooth.

Symptoms of Tooth Decay

Some of the common symptoms of tooth decay include:

  • Bad breath
  • Bad taste in the mouth
  • Bleeding gums
  • Toothache/oral pain
  • Pain when biting down
  • Sensitivity to hot or cold
  • Sensitivity to sweet foods or drinks
  • Tooth discoloration
  • Visible holes or pits in teeth

Treatment of Tooth Decay

How tooth decay is treated depends on the severity of the decay.


Useful in preventing cavities from forming in areas that you may find yourself having trouble keeping clean, sealants cover the surface of molars with a plastic material that fills in pits and crevices where toothbrushes may struggle to reach.


If tooth decay is caught early enough, fluoride treatments can be used to help remineralize the tooth enamel. You may also be asked to use a prescription toothpaste or mouthwash that will help to restore the minerals that acid has removed from your tooth enamel.


When cavities have caused damage to the tooth enamel, it’s important to have the decayed portion of the tooth removed to halt any further progress of the cavity. The removed portion of the enamel can then be repaired with a dental filling.


After the infection has been addressed, if the tooth decay has affected a large portion of the tooth where using only a filling would leave the structure vulnerable to cracks, a crown may be recommended. The crowns act as a replacement for the tooth enamel, covering and protecting the entire top of the tooth.

Root canal therapy

Sometimes, when tooth decay is not addressed soon enough, it can reach the inner parts of the tooth and cause pain and serious problems. Root canal therapy is a method for removing the infected pulp from the center of the tooth and replacing it with a rubber-like material that prevents bacteria from getting back in.


For cases where a tooth can’t be saved through root canal therapy, you may require an extraction to remove the infected tooth. Depending on the location of the tooth, your dentist may recommend a restoration such as a dental implant or bridge to prevent the surrounding teeth from shifting due to the gap.

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