Attrition is defined as which of the following?

• A. Tooth-to-tooth wear
• B. Chemical dissolution (acid)
• C. Mechanical stress causing microfractures at cervical areas
• D. Wear from external objects (e.g., toothbrush)

Answer: (A)

Attrition is tooth-to-tooth wear. It occurs when opposing teeth come into contact during chewing or grinding, creating smooth, worn facets on occlusal or incisal surfaces. This is a mechanical wear process, not chemical dissolution from acids (erosion), not wear caused by external objects like a toothbrush (abrasion), and not cervical microfractures from stress (abfraction). So the defining idea is wear from tooth-to-tooth contact.