Although many people have heard horror stories about root canals, 99% of the time it is not a painful procedure.
If the nerve becomes infected, (see toothaches) then the nerve needs to be removed from the tooth. How do we do this? the tooth is numbed using a local anesthetic. Once the tooth is numbed, an opening is made into the nerve chamber using a dental hand piece. After the access is gained, the contents of the nerve chamber are carefully removed using special instruments. The chamber and the roots are them carefully cleaned out using instruments and medications. After the canals are cleaned, they are filled and sealed using a special material. This prevents any bacteria from reinfecting the tooth. After a root canal is performed, it is imperative to have a crown placed on the tooth. The crown protects the tooth and prevents it from fracturing. After the crown is placed, the tooth returns to normal function.

As you can see from figure 1, the tooth has become infected. This can be caused by a number of factors including decay, trauma, or large failing restorations. The nerve canal which appears black in the picture signifies the death of the pulpal contents. Not only has the nerve died, but the blood vessels have also died. The nerve chamber and its contents are removed by first gaining access through the top of the tooth.

Once access is gained to the nerve chamber, the contents are removed using special instruments called "files". These are basically pipe cleaners that remove any debris inside the chamber and canals. The number of canals varies from tooth to tooth. Usually there is one canal per root. Anterior teeth have fewer canals than posterior teeth. It is important that all the canals in a tooth are thoroughly cleaned out. As you can see in figure 2, the file is cleaning the canal to the end of the root.

Once the canals have been cleaned with the files, the canals are filled with a special filling material. The purpose of this filling material is to seal the canals and prevent future infections inside the tooth. After the canals have been filled, the tooth is covered by a crown. This protects the now fragile tooth from fracture. It is important that the crown be placed soon after the root canal is finished otherwise once the tooth fractures, saving the tooth becomes near impossible.

How long will the restored tooth last?
Your restored tooth could last a lifetime, if you continue to care for your teeth and gums. However, regular checkups are necessary. As long as the root (s) of a treated tooth are nourished by the tissues around it, your tooth will remain healthy.