Basic Tooth Structure

Question 1

Basic structure

Answer 1

Each tooth divided into two:
A. Crown - covered in enamel
B. Root - covered in cementum
Crown and root joins at the cemento enamel junction or C.E.J. The line that demarks the junction is called the cervical line. Crown and root of tooth described in 2 ways.
Anatomical crown- whole crown covered in enamel
Clinical crown - crown of tooth seen only above gingivae.
Root portion of tooth may be single/ multi rooted with bifurcation or trifurcation dividing root portions into two or more roots.

Question 2

Enamel

Answer 2

Forms outer surface of anatomical crown. Has mostly densely mineralised and hardest substance in the body. Chemical composition 96% inorganic and 4% organic plus water.
Dense mineral content gives substance ability to resist the wear. Substance thickest at incisal/occlusal area but becomes thinner at cervical margin.

Question 3

Dentine

Answer 3

Forms bulk of the tooth. It is tough, slightly elastic and yellow in colour. Capable of reacting to injury and stimuli. Can repair itself by laying down secondary layer.

Question 4

Pulp

Answer 4

Embedded in dentine walls. Composed of soft, fleshy connective tissue containing nerve fibres , blood vessels and lymph. These enter through apical foramen. The part in crown of tooth referred to as pulp chamber and in the root as root canal.

Question 5

Cementum

Answer 5

Layer of pale yellow calcified tissue covering the root. Resembles bone. Main function is that it gives attachment for fibres.

Question 6

Periodontal ligament

Answer 6

Layer of connective tissue surrounding root of tooth. Occupies space between root and bony socket and attaches them firmly. Consists of fibres that connect between bone and cementum and act as cushion/shock absorber.

Question 7

Gingivae

Answer 7

Tough, fibrous layer of connective tissue covering alveolar bone of the jaws. Contains blood vessels that supply bone with nourishment. Around the neck of teeth , epithelium and outer layer of this tissue attached same way as cuticle of nail. Tight attachment prevents debris passing down.

Question 8

Dental Morphology

Answer 8

Study of shape and form of teeth.
We are then able to:
- recognise how functions of teeth determine shape and size
- understand individual functions therefore differences
- name and identify locations of various tooth surfaces
- name and identify areas within specific area on a tooth.
- define terminology used in naming landmarks