Root Decay: Causes, Risks, Symptoms & Treatment

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Medically Reviewed
by Dr. Lara Coseo
Alyssa Hill
Written by
Alyssa Hill
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Evidence Based
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4 sources cited
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What is Root Decay?

Root decay, also called root cavities or root caries, is when a lesion develops on the root surface of your tooth. These lesions typically develop close to the gingival (gum) margin. Elderly people are more prone to developing root caries. This is because people are living longer and keeping their teeth longer nowadays.

Tooth roots can only develop cavities if they become exposed due to periodontal disease or gum recession. Root decay also spreads faster than normal cavities because the cementum covering tooth roots is thinner and softer than enamel.

Causes & Risk Factors of Root Decay

Poor oral hygiene is the leading cause of all oral diseases and infections. Poor oral hygiene is caused by not brushing your teeth regularly and neglecting professional teeth cleanings.

Other factors that result in poor oral health include smoking tobacco and not consuming enough fluoride. These factors can also lead to the development of cavities (due to plaque build-up), dry mouth, gum disease, and root cavities. Root decay can form over time if your teeth roots become exposed due to long-term neglected dental care.

Common conditions that may lead to root decay include:

Advanced Periodontal Disease

The primary cause of root decay is due to periodontal attachment loss. In short, periodontal disease (PD) is a serious form of gum disease that results in permanent damage to the gums, tissues, and surrounding bone.

Patients with PD commonly develop gum recession. This condition is when the gums begin to pull away from the teeth, which eventually causes loss of periodontal attachment.

Gum recession separates the teeth from the gums. Over time, your teeth roots become exposed, which makes them more susceptible to decay.

teeth with plaque and gum disease signs

Poorly Fitted Removable Partial Dentures

If you have partial dentures that do not fit properly, gum recession may develop over time.

This is because partial dentures only replace the visible part of your teeth, rather than the entire dental arch.

removable partial denture lower jaw

Partial dentures are attached to a metal plate that is secured in the mouth using clasps and hooks that attach to your real teeth. These hooks and clasps commonly irritate the gums, which can lead to inflammation and potentially gum recession.

As a result, your teeth roots become exposed, which can lead to decay over time. If your gums are receding due to poorly fitted partial dentures, your dentist can adjust or remake them for you.

Medications & Xerostomia

Many prescription and over-the-counter medications list dry mouth (xerostomia) as a side effect. Xerostomia is a common oral condition when the salivary glands in the mouth do not make enough saliva. Saliva is necessary for cavity protection because it helps repair tooth enamel and rinses out plaque.

If your mouth produces inadequate amounts of saliva, you are more prone to tooth decay. In addition, if you have dry mouth along with periodontal disease and/or gum recession, you are more prone to developing root decay. Medications that may cause dry mouth include antidepressants, muscle relaxants, and decongestants, among others.

Other risk factors associated with root caries in older adults include:

  • Chronic medical conditions, such as diabetes, a previous stroke, Parkinson’s disease, Sjögren's syndrome (an autoimmune disease), and arthritis
  • Cognitive limitations that develop due to mental illnesses. This includes chronic depression and Alzheimer’s disease
  • Radiation treatment for neck and head cancers
  • Previous root caries

Symptoms & Complications of Root Decay

If root decay is left untreated, you may develop a serious oral infection or notice the following signs and symptoms:

  • Continuous pain near the affected area that interferes with your daily life
  • Toothache that doesn't go away
  • Difficulties eating, chewing, and swallowing
  • A dental abscess
  • Pus and swelling around the tooth
  • Loose teeth
  • Tooth loss
  • Broken or cracked teeth

Diagnosis & Treatment of Root Decay

A general dentist uses a visual exam and an x-ray to diagnose root caries during a regular dental exam. When gum recession is present, the root cavity is visible to the naked eye. Microbiological tests are also helpful in determining the presence of decay-causing bacteria on tooth roots.

Root cavities are more difficult to treat than normal cavities because they are deeper and can travel under the gum line. Depending on the severity of root decay, your dentist may recommend the following treatments:

Restorative Treatment

If the root decay is severe or develops between your teeth, your dentist may recommend a dental crown instead of a dental filling. In more severe cases, a dental implant or dental bridge may be necessary.

Root Canal Treatment

If you have root decay, there is a high chance root canal treatment may be necessary to prevent the spread of decay and save your tooth. Root cavities are closer to the dental pulp in teeth, which means there is a higher chance bacteria will spread to the pulp. The infected dental pulp must be extracted to prevent further infection, pain, and tooth loss.

Root Surface Remineralization (Fluoride Treatment)

If the lesion hasn’t progressed too deep, your dentist may recommend remineralization. This treatment involves the use of fluoride mouth rinse and toothpaste. Fluoride is essential for cavity prevention because it holds onto the calcium and phosphate in your mouth, which encourages remineralization.

Root Surface Recontouring

The earliest treatment for root decay involves the removal of softened tissue around the affected tooth. Then your dentist recontours the decayed root structure, which creates a smooth and cleanable surface.

Glass Ionomer with Fluoride Release

For severe root decay, the treatment of choice is a glass ionomer restoration with fluoride release. This type of restoration is used on any tooth in a patient with a high risk for cavities. It also releases fluoride to help prevent future cavities. Benefits include:

  • It does not cause pulpal irritation
  • It contains 20 percent fluoride
  • The procedure is relatively simple and aesthetically pleasing
  • It is anti-cariogenic, antibacterial, and adhesive to root surfaces

Preventing Cavities and Root Decay

Practicing excellent oral care and eating a healthy diet (low in sugar) helps prevent the development of cavities and root decay. Other root cavity prevention techniques include:

  • Brushing your teeth with fluoride toothpaste
  • Brushing your teeth twice a day with an electric toothbrush
  • Flossing every night
  • Getting professional teeth cleanings, dental exams, and checkups every six months


“Cavities/Tooth Decay.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 19 July 2017,

Fejerskov, Ole, et al. Dental Caries: the Disease and Its Clinical Management. Wiley Blackwell, 2015.

Garg, Nisha, et al. Textbook of Operative Dentistry. Boydell & Brewer Ltd, 2010.

“Root Caries: An Aging Problem.” The Internet Journal of Dental Science, vol. 5, no. 1, 2007, doi:10.5580/a32.

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