You’ve seen the charts and book illustrations, right? Little diagrams that have the cross-section of a tooth, with all the different parts of the tooth labeled. It’s all so simple and self-explanatory when you see it there. Of course the “root” is what the bottom part of the tooth is called, and yeah, those pinkish-red things are called gums. We know this. And the top part is called the “crown,” because crowns go on top of things. So why would we take time to talk about the parts of a tooth in a blog post like this? Because teeth are actually pretty cool and surprisingly complex. Pardon the pun, but there’s more to them than meets the eye, and we want you to know more about your amazing teeth so you’ll enjoy caring for them more! We’re going to talk about the tooth from the crown to the root.
Enamel is the tough, almost rocklike, out layer of the teeth that protects the rest of the tooth from decay. Right below the enamel is the dentin. The dentin is a little softer than the enamel, so if bacteria gets to it, decay speeds up. Dentin has teeny tiny tubes (called dentinal tubes) that run through it. When the enamel wears through and the dentin is exposed to heat and cold, the tubes carry those sensations to the softer parts of the teeth, causing sensitivity. Underneath the dentin lies the cementum. Cementum is about the same hardness as bone tissue. It covers the surface of the root and serves as the anchor point for connecting the tooth to the bone. Periodontal ligaments attach to the cementum and the jawbone, anchoring the tooth in place and giving it stability. That being said, we’ll drop down into the root now.
The pulp or nerve is in the center of the tooth and provides nutrition to the tooth. It is made of soft tissues that have nerve endings housed inside. There are two kinds of pulp: coronal pulp, which sits under the cementum, and the radicular pulp, which is the part of the nerve that runs down through the root canal all the way to the bottom of the tooth where the periodontal ligaments anchor it to the bone. At end of the root canal, radicular pulp basically merges into the periapical tissue which is full of blood vessels and nerves and runs between the tooth and the jaw, connecting with the periodontal ligaments along the way. The entire root of the tooth is covered by the gums (or gingiva), a soft tissue that surrounds the jawbone as well and provides protection for all the sensitive nerve endings housed in the root.
Here’s your free bit of trivia to go along with all this information:
When you get braces, the periodontal ligaments begin to adjust under the pressure, and cells called osteoblasts eat away at the jawbone on one side, while cells called osteoclasts build up your jawbone on the other side, to accommodate and stabilize the shift. That’s how braces work!
So there you have it: your amazing teeth! There are so many layers, so much complexity in these tiny, shiny biters in your mouth.