Q: Why do I feel pain?

A: When the pulp becomes infected due to a deep cavity or fracture that allows bacteria to seep 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.

Q: Why do I need root canal therapy?

A:  Because the tooth will not heal by itself. Without treatment, the infection will spread, bone around the tooth will begin to degenerate, and the tooth may fall-out. Pain usually worsens until one is forced to seek emergency dental attention. The only alternative is usually extraction of the tooth, which can cause surrounding teeth to shift crookedly, resulting in a bad bite. Though an extraction is cheaper, the space left behind will require an implant or a bridge, which can be more expensive than root canal therapy. If you have the choice, it's always best to keep your original teeth.

Q: What is involved in root canal therapy?

A: Once your dentist performs tests on the tooth and recommends therapy, he or she can perform the treatment or refer you to an endodontist (a pulp specialist). Treatment usually involves one to three appointments.

First, you will probably be given a local anesthetic to numb the area. A rubber sheet is then placed around the tooth to isolate it. Next, a gap 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 fight bacteria. Depending on the condition of the tooth, the crown may then be sealed temporarily to guard against recontamination, or the tooth may be left open to drain, or the dentist may go right ahead and fill the canals.

If you're given a temporary filling, usually on the next visit it's removed and the pulp chamber and canal(s) are filled with rubber-like gutta percha or another material to prevent recontamination. Occasionally a metal pin (called a post) is also inserted into the canal to help restore the tooth. The opening in the tooth is closed with a temporary filling. At a later appointment, a cap (also called a crown) may be placed.

Twisted, curved or blocked root canals may prevent removal of all inflamed or infected pulp. Since leaving any pulp in the root canal may cause your symptoms to continue or worsen, this might require an additional procedure called an apicoectomy. Through a small opening cut in the gums and surrounding bone, any remaining pulp is removed and the root canal is sealed. An apicoectomy may also be required if your symptoms continue and your tooth does not heal.

Once the root canal treatment is completed, it is essential to return promptly to have treatment completed. Because a temporary seal is designed to last only a short time, failing to return as directed to have the tooth sealed permanently with a crown could lead to the deterioration of the seal, resulting in decay, infection, gum disease and the possible premature loss of the tooth.