You know there’s a cavity in that upper molar, your tongue keeps returning unconsciously to the unfortunate spot, but you can’t bring yourself to make an appointment with the dreaded dentist, just the sound of his drill makes your skin crawl.
You continue to procrastinate. Then you bite down just the wrong way on a hard candy, the tooth cracks, and you despair. You may not lose the tooth, but you face extensive root canal work, which makes filling a cavity seem like a breeze.
The outer coating of your teeth is enamel. Beneath the enamel, dentin, a living substance, fills the crown and roots. This material in turn protects the sensitive nerve or pulp chamber in the crown, which narrows as it extends down into the roots.
A tooth may have one, two, or three roots. When a dentist does a root canal, he actually removes the pulp, composed of nerves and small blood vessels, from the chamber right down to the roots and fills the empty cavity, the canal, with another substance.
If all the nerves in your tooth have not been destroyed, the dentist gives you a local anesthetic. Then he clamps a thin sheet of rubber over and around your tooth to prevent saliva and/or the side of your mouth from touching the tooth and exposing it to germs.
Using a drill, he really goes to town, drilling right down into the pulp chamber and below. Using fine wire broaches, reamers, and files, he removes pulp and infection, enlarges the canal slightly, and smooths the walls. X rays are useful for guiding the instruments to the tip.
The canal is then irrigated with 3 percent hydrogen peroxide to kill germs and sealed with medicaments. The tooth is not filled, however, until it is completely free of germs, which requires several visits to the dentist. When there is no sign of infection, the dentist fills the root with a special cement.
He inserts a gutta percha stick or silver point into the cement to the tip of the canal and then fills the rest with cement. Again, X rays help to ensure that the entire canal is filled. Only then does the dentist put a regular filling in your weary tooth and, perhaps, add a crown or porcelain jacket for support.
Root canal work can save not only a severely damaged or diseased tooth, but even a tooth that is completely knocked out, if you get to the dentist within a half hour after your accident. The dentist can put your tooth back in place, and the thin covering of the tooth eventually will reattach itself to the jawbone. In the meantime the tooth is wired in place and cannot be used.
The dentist may do a root canal immediately, as he holds your tooth in place, or may wait until it is more secure before replacing the damaged pulp.