Endodontics is the treatment of the inside of a tooth. It is more commonly called root filling. Teeth with root fillings are dead.
In the middle of each tooth, underneath the enamel, dentine and cementum, lies the pulp of the tooth. It is very much alive and, because it is so sensitive, is popularly called the nerve of the tooth. However, as well as nerves it consists of arteries and veins and lymph glands and other normal tissues.
For a variety of reasons the pulp tissue in a tooth may die. Decay may proceed through the enamel until it reaches the pulp, allowing harmful bacteria access. The tooth may be cracked and also expose the pulp. A heavy blow on the tooth is capable of killing the pulp. When the pulp dies, it acts like all dead tissue and starts to putrefy. Very often pus is formed and starts to accumulate around the tip of the root. As it accumulates, it starts to build up pressure and hence cause severe pain. It is then called a dental abscess. If the pus builds up slowly it may not cause severe pain but turn into a chronic abscess, which starts to destroy the bone at the tip of the root. In either case, there are only two ways of treating the problem. One way is to extract the tooth, and the other is to do a root filling.
The specialist endodontist or the dentist opens up the pulp chamber of the tooth with a dental drill and proceeds to remove the dead tissue with long reamers and files which reach right to the tip of the root and clean and smooth the root canal removing the source of the infection. When it has been stabilized, the empty space is filled with a bland material, generally gutta percha, packed tightly into place with an antiseptic paste, and sealed. A well-treated root-filled tooth can last for many years. While not as good as a live tooth, it is vastly superior to any artificial substitute put in to fill the space.
Front teeth with a single straight canal are much easier to treat than posterior teeth with two, three or four curved root canals. Access to the back teeth is more restricted and such teeth are more expensive to treat. It is sometimes possible in special cases to amputate a faulty root of a multi-rooted tooth and keep the tooth to support a bridge or crown. Sometimes only the tip of the root is amputated to improve root fillings.
The main disadvantage of an endodontically treated tooth is its increased brittleness. It is often prudent to protect the dead tooth with a gold crown to minimize the risk of fracture. In some cases, especially where the crown of the tooth has been broken or weakened, a metal post is cemented into the root of the tooth above the root rilling to provide extra support and strength.
In years past, dead teeth sometimes discolored even to the extent of going black, but this is now uncommon. Nevertheless, dead teeth tend to lose their sparkle and appear dull and lifeless. Discolored teeth can sometimes be bleached. Another way of improving their appearance is to cover them with a baked porcelain crown or a porcelain veneer over the visible surface.