Introduction

This title covers a number of conditions, attrition, abrasion, erosion and resorption which, apart from dental caries, cause loss of tooth substance.

Wear of the occlusal surfaces of the teeth and of surfaces between teeth where adjacent teeth are in contact and move slightly against each other are normal accompaniments of mastication and examples are referred to here and there throughout this work. Attrition is the term used for such wear associated with tooth-to-tooth contact, but it must be pointed out that during mastication the sides of teeth not actually in tooth-to-tooth contact become smooth and polished. Attrition can under certain circumstances be excessive.

Abrasion is a term usually employed for wear of the teeth other than by food during mastication; hence surfaces other than the occlusal and contact surfaces may be affected. However, the term abrasion is sometimes used in a slightly different sense. When teeth are used, like the homodont dentitions of marine mammals, for the prehension of prey preparatory to swallowing it whole, rather than for mastication, the surfaces of the teeth become polished and worn; so also do the high-pointed cusps of the insectivores, used for grasping insects and piercing their hard cuticle before they are swallowed whole. It is often useful (Butler, 1981) to employ the term abrasion for this type of wear that occurs, it is said, without the teeth coming into actual contact.