Patient-friendly definition from the DentistsDirectory.org dental glossary.
Attrition is the progressive loss of tooth structure caused by tooth-to-tooth contact — meaning the upper and lower teeth wearing each other down through chewing, clenching, or grinding. Some degree of attrition is normal across a lifetime, but it becomes a clinical concern when it occurs at an accelerated rate or results in significant changes to tooth height, shape, or bite.
The most significant driver of abnormal attrition is bruxism — the habit of grinding or clenching the teeth, most often during sleep. Because the forces generated during sleep grinding are far greater than those during normal chewing (and the protective mechanism of pain awareness is reduced during sleep), bruxers can wear down years' worth of enamel in a relatively short time. The result is visibly flattened chewing surfaces and shortened teeth, sometimes accompanied by sensitivity and chipping along the edges.
Significant attrition raises the risk of tooth sensitivity, cracking, and eventual pulp exposure if left untreated. It can also change the vertical dimension of the bite, causing the face to look shorter and placing strain on the jaw joints. Treatment focuses first on stopping further damage — typically with a custom nightguard to protect the teeth during sleep. Once the damage is stabilised, worn teeth can be restored with composite bonding, crowns, or veneers. Severe cases may require a full-mouth reconstruction to rebuild lost tooth height.