Guide to Cavities: Causes, Symptoms & Treatment Options

Guide to Cavities: Causes, Symptoms & Treatment Options
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Guide to Cavities: Causes, Symptoms & Treatment OptionsClinical Content Reviewed by Dr. Jay Khorsandi, DDS
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Table of Contents

  1. Causes
  2. Symptoms
  3. Treatment
  4. References

A cavity is an area of one of your teeth that is permanently damaged. It develops into a tiny hole that can grow larger if left untreated.

Cavities (also known as tooth decay) are one of the most common health problems in the world, affecting people of every age, ethnic heritage, and socioeconomic status.

Cavities are caused by a number of different factors, but some people are more at risk for their development than others. Generally, bacteria in the mouth (plaque), lots of snacks and sugar (and sugary drinks), and poor dental hygiene are the conditions that help cavities form and grow.

Without treatment, cavities can grow to the point where they affect deeper layers of the teeth. This can cause a severe toothache and infection, even leading to the tooth falling out or having to be extracted to prevent more damage.

Regular visits to the dentist, twice-daily brushing, flossing, and cutting out problematic foods and drinks are the best ways to protect teeth against the development of cavities.

What Causes Cavities?

Causes of Cavities

Causes of cavities:

  • Snacks & drinks high in sugar
  • Poor oral hygiene
  • Not seeing you dentist regularly for cleanings
  • Misaligned teeth
  • Low fluoride
  • Dry mouth
  • Eating disorders
  • Smoking
  • Dental Fixtures like crowns

One of the reasons cavities are so common is that there are many causes behind their development.

Snacks and drinks that are high in sugar content are plentiful sources of fuel for the plaque that live in the mouth. Even non-sugary food, like chips, can trigger the formation of plaque that eventually causes cavities to grow.

Not brushing your teeth often enough or not flossing enough also plays a role in cavities. Having good dental hygiene is what removes plaque before it has a chance to decay and cause cavities.

However, even regular brushing and flossing cannot remove all plaque, so getting regular cleanings from a dentist is a must. A dentist has equipment and methods that can clean the teeth on a much deeper level than what you can do at home. Additionally, a dentist can also find and treat oral problems before they have a chance to become too disruptive or expensive to treat.

Having misaligned teeth can also lead to cavities. Teeth that are harder to clean can go a long time with significant plaque buildup, making them much more likely to decay than teeth that are easier to reach with a toothbrush. There are many solutions to correct misaligned teeth, thereby ensuring they get the cleaning they need to prevent cavity development.

Fluoride, Saliva & Old Fixtures

Not having enough fluoride is also a problem that can cause cavities. Fluoride is a mineral that helps against dental decay and also promotes good oral health. This is why it is included in many brands of toothpaste. However, not brushing your teeth enough means that teeth are more vulnerable to plaque and cavities.

Certain health conditions also contribute to tooth decay and cavities. People who have dry mouths will not have enough saliva to rinse off bacteria and plaque from the surfaces of their teeth. Certain eating disorders can make stomach acids come up in the mouth, which weaken the enamel and hasten its decay. Smoking also has a similar effect on the teeth, as do some medications.

Old dental fixtures, like fillings and crowns, can also be problematic. Over time, they give plaque another place to grow, and they are not always easy to clean. Dental fixtures are meant to be replaced or removed after a set time to prevent this from happening.

Many people believe that children are the only ones that get cavities, but as you age, changes in your mouth make them an adult problem, too.

What Are the Symptoms of Cavities?

Symptoms of Cavities

Symptoms of cavities include:

  • Hot and cold sensitivity
  • Lingering sensitivity to sweets and sugary drinks
  • Persistent pain in one or more teeth
  • Pressure when biting down on food
  • White, brown, or black spot on tooth
  • Hole on the surface of your tooth

There are a number of signs to alert you that a cavity has begun its formation or that a pre-existing cavity is getting bigger.

One of the most common signs that a cavity is in development is hot and cold sensitivity. Your affected tooth (or teeth) feel painfully sensitive after you have consumed something that is either hot or cold.

This is because as the cavity wears away the enamel of the tooth, it can also affect the hard tissue layer underneath the enamel, known as dentin. If dentin is too exposed, food or drink that is hot, cold, acidic or sticky can stimulate the cells and nerves within a tooth. Feeling a sharp jab of heat or cold is usually the first sign many people have of a cavity.

A very similar sign is if you experience a lingering sensitivity to sweets and sugary drinks. Processed sugars and not enough brushing and flossing wears down the enamel, exposing nerves in the teeth that are aggressively stimulated by more sweets and sugars. As with hot and cold foods, a sharp, lingering sensitivity to sugary products is another early warning sign of a cavity.

Pain & Stains

A persistent pain in one or more of your teeth can also signal the presence of a cavity, even without the sensitivity of hot, cold, or sugary consumables. This kind of pain is an almost guaranteed indicator that you have a cavity. The pain can have a very sudden onset, usually (but not always) immediately following eating or drinking. Some people experience a feeling of pressure when they bite down on their food.

Cavities cause staining on the affected tooth, usually as a white spot that sometimes develops into a black or brown spot as the decay becomes more advanced. Looking at your teeth every morning for signs of discoloration can be a good way of detecting any spotting on your teeth.

The spot on the tooth is the start of the cavity, and as this worsens, it will develop into a hole on the surface of the tooth. It is usually noticeable when looking in a mirror or by running your tongue over the surface of the teeth. If the hole forms between the teeth, it might be difficult to see or feel with your tongue, but you will still feel pain and sensitivity if hot, cold, or sugary food passes over it.

Any one of these signs is cause for scheduling a dental appointment for a possible cavity and then talking with the dentist for treatment options.

Treating a Cavity

Treatment for a Cavity

Treatment for a cavity depends on the severity and can include:

  • Early Stages: Dentist application of fluoride gel on the affected area. Reduction in sugar intake
  • Advanced Stages: Filling or crown
  • Serious Stages: Root canal or extraction. Replacement with a partial denture, bridge, or implant

How to treat a decayed tooth depends on the degree of decay. If the cavity is in its early stages, a dentist will apply fluoride gel on the affected area, to strengthen the enamel and boost the tooth’s resistance to acids in the plaque that grow cavities. The dentist will also talk to you about reducing your sugar intake as well as how often you brush and floss.

In more advanced cases of decay, the dentist might use a filling or a crown, which involves removing the cavity and filling the resultant hole after administering local anesthesia.

In serious cases of cavities, where the decay has reached the center of the tooth (the pulp, containing blood and nerves), the tooth and its root will have to be removed, a procedure known as a root canal.

Lastly, the most serious stage of tooth decay is where the tooth is damaged to the point where it cannot be repaired or restored. Instead, a dentist will replace it with a partial denture, a bridge, or an implant.


Cavities. Mouth Healthy by the American Dental Association. Date fetched: July 1, 2021.

Tooth Decay. MedlinePlus. Date fetched: July 1, 2021.

Dry Mouth and Tooth Decay. (December 2013). Sjögren’s Syndrome Foundation. Date fetched: July 1, 2021.

Tooth Decay. MedlinePlus. Date fetched: July 1, 2021.

Sensitive Teeth. Mouth Healthy from the American Dental Association. Date fetched: July 1, 2021.

Toothache. (March 2020). Cleveland Clinic. Date fetched: July 1, 2021.

Tooth Decay. National Institute of Dental and Craniofacial Research. Date fetched: July 1, 2021.

What Is a Root Canal? American Association of Endodontists. Date fetched: July 1, 2021.

Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.