A:
In understanding what a root canal is one must realize that all teeth are hollow. Inside of the hollow space is a tissue called the dental pulp. The dental pulp is made up of blood vessels, nerves, connective tissue, and a specialized cell which forms the root. When bacteria get very close or into the dental pulp, it becomes inflamed. Since the tooth is encased in a rigid structure, like your brain, the tissue has limited ability to swell. While the tissue has some ability to repair itself, it can become overwhelmed. At that point, the inflammation (irreversible pulpitis) in the tooth will not resolve and will subsequently die off (pulpal necrosis). At this stage, or if a root canal becomes reinfected over time or if a previous infection in the tooth never completely resolved, a root canal or root canal retreatment is indicated. Root canal therapy consists of cleaning, shaping, and disinfecting the hollow space inside of the tooth.
During treatment, you will recieve local anesthetic. A rubber dam will be placed to isolate your tooth from your mouth. Most treatments take one visit; however some require multiple visits.
There should not be any discomfort during treatment. Local anesthetic will be administered. The perception of numbness typically lasts between 4 and 5 hours.