Poor oral hygiene, cavities, and tooth loss increase the risk of developing certain cancers. However, scientists do not yet understand why.

Dental cavities or caries are small holes or openings in a person’s teeth. They develop when areas of the teeth decay over time. Poor oral hygiene plays a role in developing cavities, which can be worsened by tobacco use and high intake of sugary carbohydrate foods.

Scientists are unsure exactly why tooth loss correlates with cancer risk.

This article examines possible connections between cavities, cancer, and cancer treatments and discusses the causes of cavities and head and neck cancers.

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According to a 2023 meta-analysis, tooth loss is a risk factor for several forms of cancer, including:

A 2023 meta-analysis reported that tooth loss almost doubled the risk of oral cancer. Regular dental check-ups, eating fruits and vegetables, and maintaining good oral hygiene were found to reduce the risk of oral cancer.

Although scientists are unsure exactly why oral hygiene and cancer risk are linked, they have proposed the following theories:

  • Inflammation: Inflammation could be responsible for both tooth loss and various forms of cancer.
  • Carbohydrate intake: High carbohydrate intake may play a role as it is a risk factor for cancer and also a major cause of tooth decay.
  • Microbial infections: By encouraging microbial infections around the mouth, tooth decay increases the risk of certain cancers.

Cavities are a symptom of tooth decay.

According to the National Institutes of Health (NIH)Trusted Source, tooth decay arises from decay-causing bacteria.

When these bacteria come into contact with starches and sugars, they form an acid. This acid damages the tooth’s enamel, causing it to lose minerals. Over time, the acid causes the tooth to become discolored and eventually break down.

Risk factors for cavities

A person is more likely to develop cavities if one or more of the following risk factors apply to them:

  • consuming a diet high in sugary foods and drinks
  • not brushing the teeth regularly and not using fluoride products
  • having a disability that makes oral hygiene challenging
  • taking certain medications, such as those for chemotherapy or radiation therapy
  • having severe dry mouth

According to the National Cancer Institute (NCI)Trusted Source, the following factors may increase the risk of head and neck cancers:

According to the NIHTrusted Source, the following tips can help prevent tooth decay:

  • Brush with a fluoride toothpaste.
  • Drink tap water containing fluoride.
  • Use fluoride mouthwash.
  • Keep a good oral hygiene routine, which includes flossing and twice-daily brushing.
  • Limit foods and drinks higher in starch or sugar.
  • Avoid using tobacco products.
  • See a dentist for regular checkups.

The NCITrusted Source does not list cavities and tooth decay as common complications of cancer treatments.

However, both chemotherapy and radiation therapy can cause tooth decay. In the case of radiation therapy, complications can continue even after the cancer treatment is over. Additionally, cancer treatments can worsen existing cavities.

Anyone who has symptoms of tooth decay should contact a dentist. According to the NIHTrusted Source, these symptoms include:

  • toothache
  • tooth sensitivity to hot, cold, and sweetness
  • abscesses, which may cause pain, swelling, and fever

During a dental checkup, dentists typically look for signs of tooth decay, gum disease, and oral cancer.

Anyone with symptoms of head and neck cancer should seek immediate medical advice. The NCITrusted Source lists the following symptoms:

  • white or red patches in the gums, tongue, or lining of the mouth
  • growth or swelling of the jaw
  • unusual pain or bleeding in the mouth
  • persistent pain in the neck or throat
  • pain when swallowing
  • pain or ringing in the ears
  • hearing difficulties
  • trouble breathing
  • trouble speaking
  • recurrent sinus infections
  • frequent headaches
  • problems with the eyes, such as swelling
  • tooth pain

Cancer resources

To discover more evidence-based information and resources for cancer, visit our dedicated hub.

Dental cavities arise in the later stages of tooth decay, which can, in some cases, lead to tooth loss. There is evidence that losing teeth correlates with a higher risk of cancer, although scientists are not sure why.

Good oral hygiene, such as brushing the teeth regularly with fluoride toothpaste, decreases the likelihood of cavities and may help prevent types of head and neck cancers. Avoiding sugary foods and smoking can also help.