Would you consider your teeth as living things? It might come as a surprise given how hard they are, but our teeth are indeed living things! Human teeth have a unique structure and four distinct types of dental tissue, all of which work together to keep teeth healthy and strong.

The three parts that make up a tooth’s structure are: crown, neck and root. The four types of dental tissue are: enamel, dentin, cementum and pulp. Let’s take a closer look into the anatomy of a tooth to see how each separate component fits and works together to keep teeth alive and healthy.

Crown

A tooth’s crown is the portion of the tooth that is visible, and makes up about one-third of the entire tooth structure. There are three parts to the tooth’s crown: the anatomical crown, tooth enamel and dentin.

• Anatomical Crown: The “top” part of the tooth, and usually the only part of the tooth that is visible. Ideally, and in a healthy mouth, the rest of the tooth is covered and protected by the gums.

• Enamel: The outermost layer of a tooth, dental enamel is the hardest tissue in the entire human body. It is highly mineralized, protecting the tooth from bacteria and making teeth hard enough to be able to withstand the pressure from chewing. It is also the only part of the tooth that contains no living cells, which means that it cannot repair itself once damaged. – Enamel goes through a continual process of weakening (demineralization) and strengthening (remineralization) throughout every day – but once enamel has become damaged, or “broken through,” it can only be repaired artificially via restorative dental treatments like fillings and crowns.

• Dentin: The layer just underneath the enamel. Softer than enamel but harder than bone, dentin is made of living tissue and extends from the crown down through the tooth’s neck and root. Dentin contains microscopic tubules, and when enamel wears thin those tubules allow heat, cold, and acidity to stimulate the nerves inside the tooth, causing tooth sensitivity. Dentin is yellowish in color, which shows through when enamel wears away and dentin is exposed.

Neck

Also called the dental cervix, a tooth’s neck is the portion of the tooth that joins its crown and the root. The three main parts significant to the tooth’s neck are: the gums, pulp chamber, and pulp.

• Gums: Though not part of the tooth, gums are crucial to a tooth’s health and stability. Also called gingiva, gums are the fleshy oral soft tissue that covers and protects teeth roots, as well as teeth that have not yet erupted.

• Pulp Chamber: Also called the pulp cavity, the pulp chamber is the space inside the tooth that contains the pulp.

• Pulp: The innermost part of the tooth; pulp is a soft dental tissue that is made of tiny blood vessels, nerves and connective tissue. Dental pulp is responsible for the formation and nutrition of dentin; it feeds the tooth vital nutrients to keep it alive and healthy.

Root

A tooth’s root is the part of the tooth that extends into the jawbone and holds the tooth securely in place. The tooth’s roots make up about two-thirds of the entire tooth structure.

• Root Canal: The passageway that extends from the main pulp chamber down through the tooth root. – If the dental pulp within the root canal becomes damaged or infected, the tooth will eventually die. In cases such as this, root canal therapy is needed to save the tooth – a treatment in which the pulp chamber is thoroughly emptied and cleaned, and the root canal is filled with biocompatible material to maintain the tooth’s strength and structural integrity. A fully developed tooth can survive without the pulp, because the tooth continues to benourished by its surrounding tissues.

• Cementum: This hard, bone-like tissue covers the tooth’s roots and is connected to the periodontal ligament. The main function of cementum is to help anchor the tooth via its connection to those fibers which help secure the tooth within the tooth socket (the space in the jaw bone that makes room for the tooth).

• Periodontal Ligament: A system of connective tissue and collagen fiber, the periodontal ligament contains both nerves and blood vessels. Along with the cementum, the periodontal ligament connects the tooth’s roots to its socket within the jawbone.

• Nerves and Blood Vessels: The nerves help control the amount of force used when chewing and sense hot and cold; the blood vessels supply the periodontal ligament with nutrients.

• Jaw Bone: Also called the alveolar bone, the jaw bone contains the tooth sockets and surrounds the tooth’s roots, anchoring the tooth securely into place.