Anatomy of the Tooth

           The Tooth is a complex organ of mastication structured to help us in chewing, speaking, and swallowing. Every tooth has a basic composition and is shaped to perform specific masticatory function.

Structural Composition of a Tooth                                                       

In general the tooth has a crown portion which lies above the gums and the root portion lying underneath the gums and in the bone.

Tooth can be divided into three distinct sections namely, Enamel, Dentin and Pulp Chamber.

Enamel

The enamel is the outer most layer of the tooth which gives the tooth its white colour. Enamel is the hardest structure in the human body. It is comprised of prismatic crystalline structure called as Hydroxy-apatite crystals.

The thickness of enamel varies in different parts of the tooth but is thickest at the cuspal heights and incisal edges and thinnest at the junction of the crown and root called as the Cemento-enamel Junction(CEJ).

Enamel is thicker in children as compared to adults which gives the teeth a “milky white” appearance in children. The level of thickness of the enamel will determine the hue of the teeth as in the amount of “whiteness” of “yellowness” of the teeth in different individuals.

Dentin

Dentin is the next layer below the enamel and is yellowish in colour. It comprises of dentinal tubules and is porous compared to enamel. Each dentinal tubule is hexagonal in cross-section and extent from the Dentino-enamel junction (DEJ) to the pulp chamber. These dentinal tubules house the odontoblasts and their processes. These odontoblasts draw their nutrients from the pulp chamber.  

  Sensitivity in the tooth is felt by many people and the main reason for the sensation is because any cold or hot food or drink taken, will come in contact with the dentinal tubules and the shock will be sent down to the pulp chamber which holds all the nerve vessels and pain will be felt.

Pulp Chamber

This is the place where all the blood vessels and nerve vessels are present collectively called as pulp. The entire tooth gets its nutrition from the pulp. If the enamel is broken and the infection reaches the dentin then there is a very high chance for the infection to spread down to the pulp causing severe pain, swelling and even death of the tooth.