Teeth are covered with a substance we are all familiar with called enamel. Enamel is the hardest substance in our bodies. It is a glass-like covering on the tops of our teeth which protects them. When enamel is lost over the years, the substance underneath the enamel becomes exposed. This substance is called dentin. Dentin comprises most of the actual tooth. The clinical crown of a tooth has only about 2 millimeters of enamel thickness at most. Underneath the enamel, there can be six times that thickness of dentin equaling sometimes 12 millimeters of dentin. In addition, each root of our teeth is almost all dentin. There is a thin covering of material on the root called cementum, but on an exposed root there is nothing except dentin open to the environment.
The interesting and sometimes problematic aspect of dentin is that it is filled with microscopic tubules or channels that lead to the nerve chamber. Once dentin is exposed on a tooth, either through wear or through recession of the gums, it is often sensitive because the tubules inside of it connect with the nerve chamber.
When only a small amount of the enamel on front teeth is worn away and the tooth is still at an acceptable length, it is possible to cover the biting edge to veneer the dentin with harder tooth colored filling material called composite. These fillings are more similar in hardness to the enamel that used to be there and will drastically slow down the future wear of the teeth. Bonded fillings can also be done at the gumline for a sensitive tooth to cover the exposed dentinal tubules.
However, when the teeth have worn down so much that they are just not esthetically acceptable anymore, the only way to rebuild them is with crowns. This is why it is preferable to address the enamel were early on and avoid the need for crowns in the future.
There are some desensitizing toothpastes on the market that are designed to occlude any exposed dentinal tubules and thereby decrease sensitivity. There are also some prescription formulations to do the same. Don’t be fooled by the fact that dentin looks solid when viewed with the naked eye. Although it is harder than bone, it has a structure that resembles a sponge, with many channels and tubules running all the way from the outer surface of the tooth to the nerve chamber in the inside of the tooth.
At Springs Dental, Dr. Stanley J. Lis and Dr. Joshua S. Bronner believe in treating teeth conservatively to preserve as much of the natural tooth as possible. However, ignoring enamel wear is tantamount to allowing loss of tooth structure to occur in the years that follow.