Every week we answer many questions about teeth. Fortunately for us, we really like teeth and have spent years learning about them! That being said, we thought it would be helpful to write a post about the fundamentals of teeth for you. So Let’s start with the basics!
Here is the anatomy of a tooth:
- Enamel: The hard, white, outer-layer of teeth. Enamel is the hardest substance in the human body! It also has the highest mineral content (mostly hydroxyapatite). Enamel is semi-translucent in color, and composed of individual units called enamel rods. Enamel rods are aligned with one end facing out from the tooth, and one end facing the center, or pulp, of the tooth. Enamel covers the entire crown of the tooth.
- Dentin: The next supportive layer, which makes up the bulk of tooth, is a yellowish substance called dentin. While dentin in harder than bone, it is softer than enamel, with less mineral content. Dentin is composed of dentinal tubules, which radiate out from the center of the tooth or pulp. Due to the translucency of enamel, the color of dentin contributes largely to the color of teeth.
- Pulp: The pulp is the bundle of nerve and vascular cells at the center of the tooth (this is what supplies teeth with blood and sensation). This tissue is located in the pulp chamber, and extends to pulp horns and to the radicular canals. The pulp chamber gets smaller with age due to the deposition of dentin.
- Cementum: The calcified tissue that covers the root of teeth, and attaches teeth to bone via the periodontal ligament (PDL). The cementum meets the enamel at the cementoenamel junction (CEJ), or the cervical line. Cementum is what slightly yellow in color relative to enamel, and what is exposed when recession occurs.
- Periodontal Ligament (PDL): Also know as the periodontal membrane, this is a specialized connective tissue that effectively attaches the tooth to the supporting alveolar bone. One end inserts into the alveolar bone, and one end inserts into the cementum. All these fibers help the tooth withstand the naturally substantial compressive forces which occur during chewing and remain embedded in the bone.