What are Cavities?

Cavities or tooth decay is the phenomenon where teeth are broken down by acids produced by bacteria. The cavities at first turn into permanently rotten areas of the teeth, which later develops into tiny holes with time. They are also known as caries. They can becaused by number of factors. They are prevalent in children, teenager and older adults.

The cavities or caries require the following for its formation:

  • The tooth surface that includes the enamel or dentin
  • The bacteria that causes caries
  • Carbohydrates like sucrose that are fermentable
  • Time

Stages of Tooth Decay

The various stages of tooth decay are as follows:

1.Formation of Plaque:
This is a thin film that forms over the teeth due to the growth of bacteria. The inadequate cleaning
of the teeth after excessive eating of foods that contain sugar and starch is a major cause for
plaque. The bacteria eats on the sugary foods left behind forming the plaque. The plaque that
stays on the teeth will harden into tartar near the gumline. Tartar is difficult to remove and in turn
provides protection to the bacteria.

2.Attack of the Plaque
Once plaque is formed, it starts to attack the enamel, the outer layer of the tooth. This plaque has
acids that act on the enamel by removing the minerals present in it leaving behind miniscule holes
in the enamel. It further continues to erode the enamel till it reaches dentin, the next layer. Dentin
communicates to the nerve connecting to the tooth, so its erosion causes sensitivity.

3.Further Destruction
The bacteria continue to attack the tooth as the decay progresses. The damage reaches the pulp
area or the inner tooth where the nerves and blood vessels are present, leading to a swollen pulp.
This swelling expands and presses against the nerve causing the pain sensation. It can cause
further discomfort to the root and bones.


The patient will experience the following:

  • Toothache
  • Sudden pain while chewing
  • Sensitivity
  • Visible holes or pits in the teeth

Cavities are known to cause the following after a prolonged attack.

  • Severe pain disrupting normal living
  • Tooth abscess-formation of pocket pus
  • Tooth loss
  • Weight loss due difficulty in chewing and eating


The dentist usually diagnoses cavities or tooth decay by the following methods:

  • Gauging the pain and sensitivity of the tooth by asking questions.
  • Physical examination of the mouth and teeth by using gloved hands and dental instruments.
  • X-Rays will help understand the extent of the cavities.


The different Treatment options include:

  • Fluoride Treatments:
    This is done in the beginning stage of the cavity to restore the enamel. Fluorides in the form of gel or liquid are brushed onto the teeth.
  • Fillings:
    This is opted for when the cavities have progressed to the next stage.
  • Dental Crowns:
    When extensive decay occurs to teeth’s natural crown, the dentist will replace it with a dental crown.
  • Root Canals:
    This is opted when the decay spreads to the tooth pulp by repairing and save the tooth by removing the damaged tooth pulp and replaced with a filling.
  • Tooth extractions:
    This last option is done when the tooth is severely damaged it has to be removed.


  • Good oral and dental health.
  • Regular check-ups with the dentist to detect early stages of the disease.
  •  Proper brushing and Flossing.
  • Periodic dental cleanings should be performed

Authored By Dr Sanjay N - Orthodontics & Dentofacial Orthopaedics, Bangalore

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