What Makes My Teeth Hard?
Although it looks like you can see a lot of your teeth, all you really see is the hard exterior known as the crown. The crown is covered with enamel which is like body armor for your teeth, protecting their inner parts from damage.
The outside layer is composed of a substance called enamel, which is harder than your bones. Enamel must withstand pressures of hundreds of pounds when you bite on something hard.
Although the enamel is very strong, it cannot repair itself the way bone can if it is broken. The enamel protects the main body of the tooth – the dentine.
Inside the hard covering of your teeth is a soft, sensitive center called the pulp. There are nerves and blood vessels in the pulp. It’s also where the body’s blood supply connects to the tooth to deliver necessary nutrients. The pulp is what hurts when the dentist drills into your teeth.
If your teeth hurt from biting into something hot (or cold!) or a cavity, it’s the nerve endings in the pulp that sense the pain and send messages to your brain about what’s going on with your teeth. The pulp reaches all the way underneath the gums to the root of the tooth. A tooth’s roots are made up of a substance called cementum, which anchors each tooth to the jawbone.