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Abfractions and Abrasions

What are Abfractions and Abrasions?

Abfraction in upper canine tooth

Abfractions and abrasions appear very much the same—both are notches at the gumline. The difference is what causes them.


Abfractions and abrasions are an ongoing source of discussion in dentistry because, clinically, they are nearly identical, their primary treatment options are the same, and bruxism (tooth grinding) and improper alignment of the jaws and/or teeth (malocclusion) must be ruled out for both.

An abfraction is an angular notch at the gumline caused by bending forces applied to the tooth. An abrasion is a rounded notch at the gumline that may be visibly indestinguishable from an abfraction, although in cross-section abrasions are generally not as angular and have more of a saucered appearance.

With abrasions, it is believed that heavy toothbrushing forces applied to exposed tooth roots reduce the surface over time to produce the rounded notch. Abfractions, on the other hand, are caused by one of two things:

  1. Chronic heavy forces on teeth, such as may be produced by clenching or grinding the teeth (bruxing).
  2. Normal forces on teeth which are improperly aligned (malocclusion).

Abfractions that have been present for awhile may become rounded through the abrasive action of a toothbrush, especially if the teeth are continually exposed to an acidic environment, which is known to soften tooth structure.

Ruling out abfractions can save the patient time, money and unnecessary treatment. However, misdiagnosing an abfraction as an abrasion can prevent a patient from receiving needed care, and cause treatment of the abfraction to be unsuccessful.

How does the dentist diagnose Abfractions and Abrasions?

Note: ToothIQ.com contains general information. Only a dentist can properly diagnose your specific condition.

Ruling out an abfraction to diagnose an abrasion involves close visual inspection of the shape of the lesion, an evaluation of the patient’s bite (occlusion), a discussion of the patient’s brushing habits, and an evaluation for other signs/symptoms supporting the diagnosis of a tooth clenching or grinding habit (bruxism).

Symptoms that support a diagnosis of bruxism include pain, popping, clicking, grating, or locking of the jaw joints (TMJ dysfunction); headaches (particularly radiating from the temples); fatigue and/or pain from the chewing muscles (myalgia); wear planes on the teeth (attrition); reduced vertical dimension of occlusion (i.e. how far closed the lower jaw can rotate depends on where the upper and lower teeth meet. If the teeth are worn, the lower jaw can rotate farther closed- potentially causing significant problems); and a history of broken, chipped or cracked teeth and failing dental restorations.

How are Abfractions and Abrasions treated?

Treatment options for the notch-shaped lesions themselves are the same for abfractions and abrasions, generally consisting of either tooth-colored fillings to cover the notch, or covering the notch with a connective tissue graft (a surgical periodontal procedure).

Dentists may elect not to restore abfractions until they reach a depth of approximately 1 millimeter, although the conditions leading to their formation need to be understood and may require treatment. Some abfractions and abrasions cause temperature sensitivity or sensitivity to sweets, which can be conservatively treated in the short term with desensitizing compounds (e.g. paint-on solutions, special toothpastes, etc.). Magnified photographs or stone casts of the teeth can be used to monitor the abfraction / abrasion lesion for changes over time.

If the patient’s bite is a factor in development of abfractions, treatment recommendations may include orthodontic tooth movement or a bite adjustment (equilibration). Other treatment may be recommended. If the cause of abfractions is not treated, the lesions themselves may re-occur.

Because abfraction lesions are caused by abnormally high bite stress on the affected teeth, orthodontics, bite adjustments (occlusal adjustments), and/or night guards (occlusal guards or splints) may be recommended when abfractions are diagnosed. These treatments are intended to evenly distribute bite forces across all of the teeth, reducing stresses on individual teeth. They do nothing to address the cause of abrasions. However, use of a soft toothbrush and gentle brushing technique may prevent new abrasions.

It is important that all abnormal conditions in your mouth are identified and properly diagnosed, so that appropriate treatment can be prescribed, and long-term health re-established.

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Author: Thomas J. Greany, D.D.S. / Editor: Ken Lambrecht

This page was last updated on February 9, 2018.

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