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Root Caries


Root caries is one type of caries that occur usually at gums level when the gums have receded (shrunk) away to expose the root of the tooth.

Caries, also known as tooth decay or a cavity, is an infection of bacteria in origin, that causes demineralization and destruction of the hard tissues (enamel, dentine and cementum), usually by production of acid by bacterial fermentation of the food debris accumulated on the tooth surface.1 If demineralization exceeds saliva and other remineralisation factors such as from calcium and fluoridated toothpastes, these hard tissues progressively break down, producing dental caries (cavities, holes in the teeth).

The bacteria most responsible for dental cavities are the mutans streptococci, most prominently Streptococcus mutans and Streptococcus sobrinus, and lactobacilli. If left untreated, the disease can lead to pain, tooth loss and infection.2

Early root caries tends to be diffuse (spread out) and track along the cemento-enamel junction or the root surface. More advanced root lesions begin to progress toward the pulp much like dentinal caries in the tooth crown.

The root is usually protected from decay-causing bacteria by the gum. If the gum recedes, often from traumatizing brushing technique (not gentle wiggles with a soft brush), the root is then exposed.

Poor oral hygiene and decreased in salivary flow (dry mouth) are the risk factors of root caries. Dry mouth is usually related to medications, and is not age related.

The colour of the decay varies depending on the amount of the decay present and where on the tooth the decay is located. The extent of the decay through the enamel will cause different transparencies and thus different colours.

Untreated caries may progress into deeper dentine layer and might involve pulp where root canal treatment is then needed in order to save the tooth from extraction. If the caries extends deep under the gum line the tooth may no longer be restorable, hence need extraction. So, the bottom line is to get regular dental check-up for early detection and treatment if necessary.

Intraoral Factors.

  1. Low salivary flow resulting in xerostomia (dry mouth) and low salivary buffer capacity.
  2. Poor oral hygiene resulting in high plaque score and calculus deposition.
  3. Periodontal disease and periodontal surgery.
  4. Gingival attachment loss and gingival recession.
  5. Elevated salivary levels of microorganisms.
  6. Frequency of carbohydrate intake and percentage of tooth surfaces harbouring plaque.
  7. Unrestored and restored coronal and root caries.
  8. Overdenture abutments and removable partial dentures, since clasps and connectors contribute to food retention.
  9. Malocclusion, abfraction, drifting, and tipping, which makes areas of teeth inaccessible for patients to maintain proper oral hygiene.

Extraoral Factors

  1. Advanced age, since the incidence of root caries is higher in older adults.
  2. Infrequent dental check-up.
  3. Lower educational and socioeconomic levels.
  4. Gender, since males are more affected than females.
  5. Physical disability (e.g., Parkinson’s disease) where patients have limited manual dexterity that makes the removal of plaque during tooth brushing difficult.
  6. Medications that decreases the salivary flow.
  7. Diabetes, autoimmune disorders (e.g., Sjogren’s Syndrome), or radiation therapy.
  8. Antipsychotics, sedatives, barbiturates, and antihistamines.
  9. Limited exposure to fluoridated water.
  10. Addiction to alcohol or narcotics.

Sign and symptoms


Many people who have root caries do not know that they exist in their mouth. Usually it occurs at or even below the gum line, where the warning signs that often accompany tooth decay, such as sensitivity to cold or sweets, may be absent. In addition, as we age our teeth become less sensitive and may not warn us that the tooth is already damaged.

Often root caries is first found when the patient does their dental check-up. Radiographs (x-rays) can be helpful in finding root caries between the teeth (interproximal root caries) and tooth surfaces that are hidden from normal vision.


Root caries is often deceptive. Even when the cavity can be seen with the eye, it often appears small and not very alarming. However, because the damage is to the foundation of the tooth, a little damage can weaken the entire tooth and put it at risk for breaking off at the gum line.

Similarly, what appears to be a small amount of damage to the tooth may require a crown instead of a filling. Damage may have gone all the way into the pulp of the tooth and may require endodontic therapy (root canal treatment) to prevent pain and infection. At times, so much damage has been done that the tooth must be removed. That is why it is so important to have frequent examinations for early detection.

Any type of filling material such as amalgam, resin composite, glass ionomer, and compomer can be used for root caries filling but resin-modified glass ionomer materials is recommended for these restorations because of their aesthetic value and cariostatic properties in patients with a high caries risk.


Since root caries is caused by bacteria, the most important thing that can be done is to keep our teeth clean every day. Cleaning can be more difficult in receded gum. Proper method and effective cleaning technique is necessary to handle root caries cases that have been filled in order to effectively remove plaque: soft / medium bristle toothbrush in a firm, non-traumatic motion together with the use of dental floss, and/or interdental toothbrush. Be sure to tell the dentist if one has physical limitations that make it more difficult to clean the teeth.

In addition to keeping the mouth clean, fluoride has been shown to be very important in the prevention of root caries. There are now many forms, application technique and concentration of fluoride depending on one’s need, such as fluoride treatment at dental clinic. Many fluoride containing products are also available and may be helpful to further prevent root caries.

Diet is also a very important factor because certain foods and snacks can greatly increase the number of bacteria that forms the decay-causing plaque.

Finally, frequent professional cleanings and examinations can help prevent root caries or find it early when it can be more easily repaired.


  1. MedlinePlus Encyclopedia Dental Cavities
  2. Cavities/ tooth decay, hosted on the Mayo Clinic website. Page accessed May 25, 2008.
Last Reviewed : 23 August 2019
Writer : Dr. Saripah bt. Saud
Accreditor : Dr. Kamarul Hisham bin Kamarudin
Reviewer : Dr. Roshima bt. Mohd Sharif