When the nerve of a tooth becomes infected, root canal treatment can save the tooth. How do you know if you have an infected tooth? Some of the signs are heat and cold sensitivity, swelling and pain, or a bad taste in your mouth. Or, you may experience no symptoms at all and not realize that you have a dental problem.

To get at the infection, he makes an opening through the top of the tooth down into the pulp chamber. With a dental file, your dentist (or endodontist) carefully cleans out the infected tissue and shapes the canals to receive the filling material. X-rays are taken to make sure that all of the infected pulp is removed.

Root canal therapy often takes two or more appointments to complete. A temporary filling or crown is placed to protect the tooth between appointments.

After each appointment when anesthetic has been used, your lips, teeth and tongue may be numb for several hours. Avoid any chewing until the numbness has completely worn off.

Between appointments, it's common (and not a problem) for a small portion of your temporary filling to wear away or break off. If the entire filling falls out, or if a temporary crown comes off, call your dentist so it can be replaced.

It's normal to experience some discomfort for several days after a root canal appointment, especially when chewing. To control discomfort, take pain medication as recommended. If antibiotics are prescribed, continue to take them for the indicated length of time, even if all symptoms and signs of infection are gone.

To further reduce pain and swelling, rinse three times a day with warm salt water; dissolve a teaspoon of salt in a cup of warm water, then rinse, swish, and spit.

To protect the tooth and help keep your temporary in place:

? Avoid chewing sticky foods (especially gum).

? Avoid hard foods and hard substances, such as ice, fingernails and pencils.

? If possible, chew only on the opposite side of your mouth.

It's important to continue to brush and floss normally. Usually, the last step after root canal treatment is the placement of a crown on the tooth. A crown covers and protects the tooth from breaking in the future.

If your bite feels uneven, you have persistent pain, swelling, bleeding (bruising) or you have any other questions or concerns, call your dentist right away.

If after root canal treatment has been performed a tooth still harbors bacteria or irritants which keep the tissues surrounding the root of the tooth from being healthy (inflamed), then the treatment has not been successful. Some signs of failed root canal treatment can include tooth pain (ranging from very mild to extreme) and tenderness or swelling in the gums in the area near the tooth (ranging from very slight to pronounced). These signs can either:

?Persist from the time of the root canal treatment.

?Be transient (varying week to week or month to month.

?Appear even though the tooth has been asymptomatic for years.

In other cases a tooth may have been, and continues to be, without symptoms but the tissues surrounding the tooth are identified as having the presence of persistent inflammation by way of a x-ray examination by a dentist. In these cases, if retreatment is not a possibility, then the tooth should be extracted.