Teeth play a major role in speech as well as eating, and there is a lot more to them than what you can see in a smile! Four different types of tissue make up in the structure of teeth: enamel, dentine, cementum and the pulp.
Enamel is the hardest tissue in the human body because of it’s concentrated mineral content, but is also brittle. It forms as the tooth is developing under the gum before it erupts. The crown of the tooth – visible above the gumline – is covered in a layer of enamel, which varies in thickness between individuals. Enamel has no blood supply or living cells, and apart from a degree of repair during normal remineralisation, does not regenerate or recover from significant damage.
Enamel wears down over a life-time of use. A diet high in sweet and acidic foods exposes the enamel to greater erosion and wear. Healthy diet, good oral hygiene and preventative dentistry help maintain tooth enamel.
Dentine, or ‘ivory’, makes up the main body of the tooth. Above the gum – the crown of the tooth – it is covered and protected by enamel. And the roots below the gumline are lined with cementum. Dentine is softer than enamel, has no blood supply, but does contain nerves.
If decay descends through enamel, or vigorous tooth brushing pushes back the gums and abrades the enamel, the nerves in dentine are responsible for pain. The softness of dentine compared to enamel allows decay to progress much faster through this inner part of the tooth.
Below the surface
Cementum is the calcified lining of the roots of the tooth, connected with periodontal fibres and gingival fibres to attach the tooth to the surrounding bone and gums. Cementum provides a firm yet cushioned hold on the tooth.
Finally, the pulp of the tooth is found in the innermost part. It has a blood supply and nerves and keeps the tooth alive. Any trauma, infection or decay that involves the pulp results in severe pain. The design and structure of teeth aims to protect this special vital pulp to prolong the life of the tooth.