Why Teeth Break

In my dental practice I probably see at least one or two people every single day who come in with a broken tooth. Many times they’ll tell me that they were chewing on something soft and then all of sudden it just broke. They’re often confused about how it even happened. We’ll take a look at the most common reasons teeth break and what you can do to prevent it. Just before we get to that here’s a quick primer on how a tooth is set up.

This is a rough diagram of a tooth. It shows the outermost layer of enamel, an inner layer of dentin, and the innermost layer is the pulp space

The enamel layer of the tooth is the hardest but also the most brittle if it doesn’t have something to support it. It’s main purpose is to provide an extremely durable surface for chewing and protection of the rest of the tooth.

The dentin layer is softer than the enamel but still very hard. It similar to how hard a bone is. It’s main purpose is to support the enamel.

The pulp contains the cells, blood vessels, and nerves needed to keep your tooth healthy.

Now that we understand all that, let’s take a look at why exactly teeth break.

Reasons Why Teeth Break

Teeth, especially the ones in the back of your mouth, take a tremendous amount of force. An average man can exert nearly 150 pounds of pressure on his back molars and nearly 70-80 pounds on his front teeth. Teeth are much like the foundation of a house. Even with great care, over time they will develop cracks and wear from the the constant everyday pressure they are under. It is actually pretty incredible that teeth are able to hold up so well over the course of your lifetime considering how much punishment they take.

• Cavities
  • Cavities are the most common cause of broken teeth. Cavities start at the surface of your teeth and then spread out through the dentin. When enough of the dentin has been destroyed, the enamel no longer has any support under it and will easily fracture if pressure is applied to it.
  • Imagine two pieces of glass. The first one is resting on a flat piece of plywood. The second is resting on just two small pieces of wood on each end. If you apply pressure downwards, which one do you think will break? Obviously the second one right? It has no support underneath and is easily broken. The first piece of glass on the other hand has good support underneath all of it and will be almost impossible to break. Your teeth are the exact same way.
• Weak after a previous filling
  • Even if you have your cavities taken care of, fillings can leave your teeth weaker than before. Over time the process of chewing creates small cracks in these teeth. Once these cracks have made it all the way through your tooth, you end up with a tooth that cracks.
  • Having fillings are still always better than leaving cavities. Fillings help to rebuild that support for the tooth.
• Wear from grinding
  • Grinding speeds up the wear on a tooth tremendously. Most people’s teeth only touch for a fraction of a second when they swallow or chew. People who grind generally spend an entire night with their teeth grinding together. If you couple this with a weak tooth from a cavity or filling and you’ve got all the right ingredients for a broken tooth.

Prevention

• The most important thing you can do to prevent your teeth from breaking is to not get cavities. Teeth that have never had dental work very rarely break, unless you are a very serious grinder.
• If you are a grinder, you should seriously consider wearing a nightguard. You can either have a nightguard made at your dentist’s office, have one made for you by a dental lab, or you can use our guide to make your own custom nightguard at home. A nightguard will take take all the force created by your grinding and distribute it more evenly as well as wearing itself instead of the teeth.
• Don’t regularly chew on ice or other extremely hard things like nuts. Your teeth just can’t stand up to that kind of consistent force.
• See your dentist regularly to check for cavities. It usually takes a pretty large cavity before a tooth will break.
• If you have a large filling or cavity on your tooth (or both) and your dentist recommends a crown, you should probably get it done. A crown slides over top of the tooth and helps hold everything together. This prevents your teeth from breaking.