Abfractions and Abrasions
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:
- Chronic heavy forces on teeth, such as may be produced by clenching or grinding the teeth (bruxing).
- 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.