1. Changes in bone causing it to become dense and hard like ivory.
2. The thinning or absence of articular cartilage, as occurs in degenerative joint disease; such that the subchondral bone is exposed and lines parts of the articular cavity.
3. The polished, burnished appearance taken on by exposed dentin; dentin eburnation.

A condition observed in arrested dental caries wherein decalcified dentin is burnished and takes on a polished, often brown-stained appearance.