Root canal treatment is often the choice whenever a tooth causes serious pain to an individual. The tooth may hurt for one of many different reasons:
1. There is very deep, extensive tooth decay that has affected the nerve.
2. There is a very large, extensive filling in that tooth (that may have been there for a long time)
3. The tooth was recently traumatized by a blow of some kind.
4. Accumulated dental treatment to that tooth has caused the nerve to react.
Whatever the reason, to all practical purposes, if a tooth causes ongoing pain, the nerve should probably be removed, and root canal treatment is the way we do that. Once the root canal system is cleaned out, and shaped, it is then filled with a special root canal obturation material. The other important fact is that a healthy nerve supplies water (via the blood supply) to the dentin of the tooth. Once the nerve is no longer there, the tooth has no water-supply and becomes brittle; and the brittleness increases over time.
The brittleness coupled with substantially less tooth structure, makes it easy to see how a sudden bite on something hard could cause the tooth to fracture. Often, a root-canal-treated-tooth fractures such that it cannot be restored, and must be extracted. Neither the dentist nor the patient wants that to happen. For this reason, the best preventive against fracture, that we have at the present time for a root-canal-treated-tooth, is a full crown.
A crown can be made of different materials. Sometimes full gold crowns are placed. But, today, we can make crowns of tooth-coloured ceramic materials that look, feel, and function like real teeth. These are just examples of what can be done.
Everyone deserves to have natural-looking, and healthy-functioning teeth. Modern Dentistry can do some pretty amazing things.