Before root canal therapy came into practice, if you had a tooth with a diseased nerve, you'd probably lose that tooth.
Deep beneath each tooth's outer shell is an area of soft tissue called the pulp, which carries the tooth's nerves, veins, arteries and lymph vessels. Root canals are very small, thin divisions that branch off from the top pulp chamber down to the tip of the root. A tooth has between one and four root canals.
When the pulp becomes infected, usually from a deep cavity or fracture that allows bacteria to creep in, or injury due to trauma, it can die. Damaged or dead pulp causes increased blood flow and cellular activity, and pressure cannot be relieved from inside the tooth. Pain in the tooth is commonly felt when biting down, chewing on it and applying hot or cold foods and drinks.
Left untreated, pus builds up at the root tip, in the jawbone, forming a "pus-pocket" called an abscess. An abscess can cause damage to the bone around the teeth. Without root canal therapy, the tooth may have to be pulled, causing surrounding teeth to shift crookedly, and resulting in a bad bite. The space left behind may require an implant or a bridge, which can be more expensive than root canal therapy.
Root canal therapy is performed in order to save the damaged or dead pulp in the root canal of the tooth. The procedure involves cleaning out the diseased pulp and reshaping the canal. The canal is filled with a rubber-like material to prevent recontamination of the tooth. The tooth is then permanently sealed with either a post or gold or porcelain crown. This enables you to keep most of your original tooth.
In most cases, a root canal is a relatively simple procedure with little or no discomfort involving one to three visits.
During the first visit, you will probably be given a local anesthetic to numb the area. A rubber sheet may be placed around the tooth to isolate it. Next, access is drilled from the crown into the pulp chamber, which, along with any infected root canal, is cleaned of all diseased pulp and reshaped. Medication may be inserted into the area to kill bacteria and prevent additional infection. Depending on your tooth's condition, the crown may then be sealed temporarily to guard against recontamination, or the tooth may be left open to drain. In some cases, the canals may be filled right away.
On your next visit, a temporary filling (if one was applied during the first visit) is removed and the pulp chamber and canal(s) are filled with the rubber-like material to prevent recontamination. If the tooth is still weak, a post may be inserted above the canal filling to reinforce the tooth. Once filled, the area is permanently sealed. Finally, a gold or porcelain crown is normally placed over the tooth to strengthen it's structure and improve appearance.
Root canals have an extremely high rate of success (usually higher than 95 percent).