Tooth Abrasion and Attrition

Abrasion and attrition are the two principal forms of mechanical, non-carious tooth wear. Abrasion is hard-tissue loss caused by friction from a foreign object - classically a toothbrush or abrasive paste - while attrition is loss caused by direct tooth-to-tooth contact, as in chewing or grinding. Both interact closely with chemical erosion.

Definition

Tooth abrasion is mechanical wear of dental hard tissue caused by friction from a foreign object, while attrition is mechanical wear caused by tooth-against-tooth contact; both are non-carious forms of mechanical tooth wear.

Scope

This entry distinguishes abrasion from attrition, describes their mechanical mechanisms, and explains how they combine with erosion to produce tooth wear. It is a reference description and does not provide diagnosis or treatment guidance for any individual.

Core questions

• How does abrasion differ from attrition?
• What foreign agents typically cause abrasion?
• How does grinding or normal occlusal contact produce attrition?
• Why are mechanical wear and erosion usually considered together?

Key concepts

• Abrasion (foreign-object wear)
• Attrition (tooth-to-tooth wear)
• Mechanical tooth wear
• Erosion-abrasion interaction
• Multifactorial tooth wear
• Surface softening before mechanical loss

Mechanisms

Abrasion results when an external agent rubs against the tooth and removes hard tissue - common examples include toothbrushing with abrasive dentifrice or habitual contact with objects - whereas attrition results from the tooth contacting opposing teeth during function or parafunction such as bruxism. These mechanical processes rarely act in isolation: acid erosion softens the tissue surface and makes it more readily removed by friction, so chemical and mechanical wear potentiate one another, and observed wear is typically the product of their interaction rather than any single process (Addy & Shellis, 2006; Shellis & Addy, 2014). For this reason mechanical wear is generally discussed within the multifactorial framework of (erosive) tooth wear (Lussi & Carvalho, 2014).

Clinical relevance

Distinguishing mechanical from chemical contributions to tooth-surface loss, and recognising that they interact, is part of how clinicians frame tooth wear. This entry describes these processes for orientation only and does not prescribe diagnosis or treatment for any individual.

History

Terminology separating abrasion, attrition, and erosion was consolidated in the twentieth century, and later work emphasised that these processes interact rather than act independently, reframing mechanical wear as one component of multifactorial tooth wear (Addy & Shellis, 2006; Shellis & Addy, 2014).

Debates

How separable are abrasion, attrition, and erosion in practice?

Although the three processes are defined distinctly, their close interaction - notably acid softening preceding mechanical removal - leads many authors to treat tooth wear as a single multifactorial entity rather than to attribute observed loss to one mechanism.

Key figures

• Martin Addy
• R. Peter Shellis

Seminal works

• addy-shellis-2006
• shellis-addy-2014

Frequently asked questions

What is the difference between abrasion and attrition?

Abrasion is wear from a foreign object rubbing the tooth, such as a toothbrush or abrasive paste, while attrition is wear from direct tooth-to-tooth contact, as in chewing or grinding. Both are mechanical, non-carious forms of tooth wear.

Why are these often discussed alongside erosion?

Acid erosion can soften the tooth surface so that it is more easily worn away mechanically, so abrasion, attrition, and erosion tend to act together; many authors therefore treat tooth wear as a multifactorial process rather than the result of one cause.