Tooth structure is brittle in nature. As you chew, mostly compression forces are exerted on your teeth. If your teeth don’t hit right or if you bite a hard object (i.e. nuts, ice, hard candy, etc.) just wrong, it will subject your tooth to more of a shear force (see figure below). Brittle materials are very strong in compression forces but are weak when subjected to shear forces. Over time, little cracks form in your teeth and they will become bigger as you chew, especially when shear forces are applied.
Oftentimes a small crack will be visible on the tooth and we will take a photograph of it and show you. Dr. Frost will usually keep an eye on the smaller cracks and advise you to stay away from hard foods. If the crack is large or the tooth seems thin or undermined, Dr. Frost will advise you to protect the tooth with a crown. It is important to catch cracks early. If the crack spreads to the root of the tooth, the likely outcome is that the tooth will need to be extracted to prevent bone loss around surrounding teeth. Cracks may spread quickly and are very difficult to predict. For example, compare a crack in your tooth to a crack in the windshield of your car. You might have a crack in your windshield for many years without any problems and then, unexpectedly, the crack spreads all the way across the windshield. On the other hand, you might have a crack for only a couple of hours before it spreads across your windshield.