Chicago Family Dentist

The teeth are made up of 4 main components: the dentin, enamel, pulp, and cementum. Cementum is a calcified substance that covers the root of a tooth. It is excreted by cementoblasts, special cells in the root, and it is thickest at the apex of the root.

Much like dentin, the color of cementum is yellow-ish. In addition, it is softer than both enamel and dentin. The softer state of cementum is due to it being less mineralized than the other two tooth coverings. While it is softer, it is not, by any stretch of the imagination, a soft substance.

Cementum fills an important role in the mouth. It is the anchoring point for the periodontal ligaments. These ligaments hold the tooth in place and give it its stability. Without the periodontal ligaments, teeth would wiggle around a lot more. The cementum is attached to the ligaments through collagen fibers.

Because of this role, the bottom portion of the cementum is tangent to the periodontal ligaments which run through the jaw. The upper portion of the cementum is cemented to the dentin that supports the enamel.

In addition to being in contact with the dentin of a tooth, cementum also meets the enamel. It meets the enamel lower on the tooth at the cemento-enamel junction. Here, cementum is known as acellular cementum because it lacks cellular components. It covers between one-third and one-half of the root. Cellular cementum covers one-third to one-half of the root apex. This is where it binds itself to the dentin. The final type of cementum is afibrillar cementum. This type frequently extends onto the enamel of the tooth. 

In terms of chemical makeup, cementum is very similar to bone. The biggest difference is that cementum lacks blood supply (vascularization). It is composed of roughly 45% inorganic material, 33% organic material, and 22% water.

For more information on dental health, contact Chicago family dentist Dr. Sumeet Bagai at 773-767-1554.