A human adult tooth can be broken down into two big parts: Crown and Root(s). Crown of a tooth refers to the part of the tooth we can see above the gum line. It is not to be confused with a crown restoration (sometimes referred to as “cap over a tooth”) as this refers to the anatomical naming, not the dental treatment. Root(s) of a tooth refers to the part of the tooth we cannot see and is below the gum line (mostly). A tooth can have upto one to three roots. Four and five roots are possible but are rare.
The crown of the tooth consists of three layers: Enamel, Dentin, and Pulp.
Enamel is the hard outermost layer of the crown of the tooth. As it is the outermost layer of the tooth, it can be easily visualized by just simply looking at the teeth’s surface. Composed of inorganic materials such as calcium and phosphate, which makes up a structure called hydroxyapatite, enamel is the protective layer that protects the tooth from various physical and chemical agents.
Dentin is the second layer of the crown of the tooth. It makes up the most volume of the crown of the tooth. Dentin is also responsible for the color of the tooth – light yellow. Sometimes when one has mechanical wear or chemical wear on the tooth, dentin is exposed and can be visualized.
Pulp is the innermost layer of the crown of the tooth and at the center of the tooth. It consists of live nerve tissues and subsequent blood vessels that are connected to the more complex nerve/circulation system of the body. It can only be visualized by the dentist when an access is made through the enamel/dentin layer by removing said layers. Pulp is responsible for making the teeth have cold/hot sensation along with pain. It also is responsible for proprioception of the teeth, enabling it to sense the pressure that comes from the chewing or biting.
The root of the tooth consists of three layers as well: Cementum, Dentin, and Root Canal(pulp). Cementum is the outermost layer of the root of the tooth. It is similar to dentin in its composition but is softer due to having less inorganic material content and more organic content such as collagen. It surrounds the entire length and diameter of the root of the tooth. The delineation at which enamel ends and the cementum starts is named cementoenamel junction(CEJ).
Dentin is the second layer of the root of the tooth and is continuous from the crown part of the tooth.
Root canal is the innermost layer of the root of the tooth and is a small tube-like structure that contains pulp inside thus being called a canal. Root canal treatment is named after this part of the tooth as the treatment effectively occurs inside of this part of the root.
This concludes the brief(?!) and simple breakdown of the basic anatomy of a tooth. I know… it’s so very interesting 😀 As with any other medical knowledge and facts, learning about teeth and what goes on inside one’s mouth can be overwhelming and complicated. I am here to try to explain in somewhat detailed but understandable terms as best as I can. My goal is for my patients to understand on a basic level his/her dental health and be able to make informed decisions about everyday dental hygiene and treatments, should he/she needs them.
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