The tooth: crown, root, enamel, dentine and pulp
- Anatomy and histology
A tooth has a hard outer shell (enamel and dentine) around a living core (the pulp) with nerves and vessels. Each layer explains a different kind of pain.
See it in 3D: Gums (gingiva)
What it is
Each tooth has a crown above the gum and one or more roots held in the alveolar bone. Enamel covers the crown, cementum covers the root, and dentine forms the bulk of both. In the centre, the pulp chamber and root canals hold loose connective tissue, nerves and vessels that enter through the apical foramen at the root tip. The tooth is joined to bone by the periodontal ligament, not fused to it.
Clinical anatomy
- Crown: the part covered by enamel; the neck (cervical line) is where enamel meets cementum.
- Root: covered by cementum; incisors and canines usually have one root, upper first molars three and lower molars two.
- Enamel: the hardest tissue in the body, almost entirely mineral, with no cells and no nerves.
- Dentine: tubules run from the pulp to the enamel; fluid moving in them is felt as sharp pain (sensitivity).
- Pulp: nerves, vessels, fibroblasts and odontoblasts, enclosed in rigid walls with a single narrow entrance at the apex.
Function
- Odontoblasts lining the pulp keep laying down dentine throughout life, so the pulp chamber narrows with age.
- Pulp nerves mostly signal pain, whatever the stimulus (cold, heat, pressure, sweet).
Clinical correlation
- Because the pulp cannot swell inside rigid walls, inflammation raises pressure and can strangle its own blood supply: pulpitis can end in necrosis.
- Exposed dentine (receding gums, worn enamel) gives short, sharp pain to cold that stops when the stimulus stops.
- Enamel does not regenerate: once a cavity breaks through it, only a restoration can replace it.
Next step / Initial management
- Tooth pain: locate the layer involved (dentine, pulp or periodontium) with history, cold test and percussion.
- Short pain to cold that stops at once: suspect exposed dentine or shallow caries and refer for routine dental care.
- Lingering or spontaneous pain, or pain on biting: refer to the dentist promptly for pulp or periapical disease.
Test yourself
Think of the answer, then tap the question to see it.
Which dental tissue has no cells and cannot repair itself?
Enamel: it is almost entirely mineral and is not regenerated once lost.
Why can pulpitis end in pulp necrosis?
The pulp is enclosed in rigid dentine with one small apical entrance; swelling raises pressure and cuts off its blood supply.
What attaches a tooth to the alveolar bone?
The periodontal ligament, between the root cementum and the bone of the socket.
Elsewhere in DurgiPedia
Connections
See it in 3D1
The structures of Durgical's 3D anatomy where it is found.
Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.
Sources: Anatomy, Head and Neck, Teeth (StatPearls Publishing (NCBI Bookshelf), 2023); Physiology, Tooth (StatPearls Publishing (NCBI Bookshelf), 2023); Anatomy, Head and Neck, Dental Pulp (StatPearls Publishing (NCBI Bookshelf), 2025).
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Representative model, for educational purposes only.