Introduction to Teeth - Dental Biotribology - page 4

contact by mastication, and it is not considered to cause any damage. However,
based on tribological terms, “attrition” would be clearly subsumed under other well-
defined surface damage mechanisms. Moreover, there is a huge difference in the
definitions of the term “erosion.” It seems that the meaning of “erosion” used in
tooth loss is similar to that of “corrosion” used in tribology. In 2004, Grippo et al.
[ 12 ] also proposed that the term “erosion” should be deleted from the dental lexicon
and replaced with the term “corrosion” to denote chemical dissolution of teeth. In
addition, “abfraction” is more or less related to higher bite force or repeated contact
load, pointing to a relationship with the effect of fatigue. It might potentiate tooth
wear by abrasion and/or erosion. On the contrary, the term “adhesion,” which is
widely used in the field of tribology, is not encountered in the dental literature. The
explanation might be that dental tissue, particularly dental enamel, is similar to
ceramic materials; perhaps adhesive wear would not occur at the tooth surface dur-
ing the masticatory process. Nevertheless, respecting disciplinal differences and
development history, these terms will still be used although engineers and medical
researchers should use care when reading these terms in the literature.

1.3 Anatomy and Function of Human Teeth

Human teeth possess a unique structure [ 13 ] composed of enamel, the dentin-
enamel junction, dentin, and pulp (shown in Fig. 1.1 ); each zone is anisotropic. The
two most important elements of a tooth from a tribological perspective are the outer
enamel and the inner dentin, whose properties [ 14 ] are given in Table 1.2 .

Crown

Enamel

Dentine

Gum

Pulp cavity

Neck

Pulp (containing blood
vessels and nerves)

Cementum

Root

Fig. 1.1 Human tooth structure [ 13 ]