The Main Causes Of Cavities And Tooth Decay

By Ashley Henshaw. May 7th 2016

There are few adults who can claim they’ve never had a cavity. Even though most people have experienced this condition, few know what actually happens to a tooth when it gets a cavity. For example, did you know that cavities are actually the term used to describe a type of tooth decay? Fortunately, it’s possible to have a few cavities and still have relatively healthy teeth. Better yet, there are some easy ways to help avoid getting cavities and save your teeth from tooth decay.


Cavities are a type of tooth decay that occurs when acids in dental plaque dissolve the enamel of the tooth’s surface, creating a physical hole or opening in the tooth. This is permanent damage to the tooth that cannot be fixed. Over time, cavities can become larger and deeper, so it’s important to seek treatment immediately.


There are three main types of cavities, each of which are classified by the area of the tooth which they affect:

  • Smooth surface cavities develop on the smooth sides of the teeth in the area where you would normally floss.
  • Pit and fissure cavities develop on the top of the tooth which you use to chew your food.
  • Root cavities develop under the visible part of the tooth on the surface that covers the roots of the teeth.


There are many symptoms associated with cavities, including:

  • Toothache or tooth sensitivity
  • Pain when eating or drinking something with a hot or cold temperature
  • Pain when biting down
  • Pus around the tooth, particularly when pressing on the gums
  • Visible holes or pits in the teeth

It’s important to note that when a cavity first forms, there are often no symptoms present. That’s why it is important to see a dentist regularly even if you don’t believe you have any cavities – the doctors are able to spot cavities and ensure they don’t get any worse. If you do experience the signs and symptoms listed above, make an appointment with a dentist as soon as possible.

Causes And Risk Factors

The main cause of cavities is dental plaque. This soft, sticky film forms on the teeth when they are not cleaned sufficiently. The bacteria, acids and food particles in your mouth all combine to form plaque on the surface of the teeth. The acids in particular will start to wear away the tooth’s enamel. At this point, bacteria and acid start reaching even deeper levels of the teeth, including the dentin. By this time, a cavity has begun to form. However, the deeper layers of the teeth are not as resistant to bacteria and acids as the enamel, so the decay will continue to progress, making the cavity larger and much more serious.

Teeth at the back of your mouth – including the molars and premolars – are most susceptible to cavities because they are often used to grind and chew food. In addition, they contain numerous grooves and pits which make for excellent places for food particles and bacteria to get stuck and form plaque. These teeth are also harder to keep clean compared to the front teeth.

There are several risk factors which may contribute to a person’s increased odds of getting a cavity, such as:

  • Inadequate brushing and flossing
  • Frequent snacking and sipping
  • Eating certain foods, including anything sugary, starchy or sticky
  • Lack of fluoride, a mineral which added to public water systems and many toothpastes
  • Being in your childhood or teenage years
  • Being an older adult
  • Dry mouth
  • Having an eating disorder
  • Having frequent heartburn
  • Worn dental fillings or devices
  • Undergoing certain cancer treatments, such as radiation


The best way to prevent cavities is to keep good oral hygiene habits. That includes brushing at least twice a day with a fluoride toothpaste and flossing daily. You can also brush your teeth after every meal for even better results. If you can’t brush after every meal, use a mouthwash or rinse your mouth thoroughly with water.

In addition to brushing and flossing, seeing a dentist regularly is key to preventing cavities. These doctors will provide thorough cleanings and be able to detect cavities in their early stages. You can also talk to your dentist about dental sealants, which are protective plastic coatings applied to the teeth to help prevent cavities. These are strongly recommended for school-age children and can be replaced about every 10 years.

The last step in prevention concerns dieting habits. Avoid constantly snacking on foods or sipping on drinks, both of which expose your teeth to bacteria and acids relentlessly. You should also eat limited amounts of sticky, sugary and starchy foods, including chips, cookies and candy. Instead, have cheese, fresh fruits and veggies or sugar-free gum. These foods help prevent cavities by getting rid of excess food particles in the mouth.


If cavities are caught in their early stages, they may be treated with fluoride. This can help to restore the enamel on the affected teeth. However, most cavities need to be fixed with a filling. For this process, the doctor drills away any decayed parts of the tooth and fills the hole with the filling to restore the tooth’s shape and prevent the cavity from worsening.

Extensive tooth decay requires a more intensive dental procedure, such as a crown (which covers the tooth) or a root canal (when the tooth pulp is removed and replaced with a filling). When a tooth is beyond repair, a dentist will perform an extraction. In these situations, a bridge or dental implant can be added to replace the missing tooth.


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