A root canal is usually done by an endodontist or a general dentist. The root canal usually takes one or two visits, but sometimes additional visits are required because some teeth prove difficult to treat. First, you have dental X-rays to check the extent of the damage. You also receive a local anesthetic to control pain, which may be more severe if the tooth is abscessed. Then a rubber-like sheet called a dental dam is put in your mouth to keep the tooth clean, protected, and free of saliva. Decay is removed, and an opening is made through the tooth's crown to gain access to the pulp chamber. Using small dental instruments, the infected or diseased pulp is removed.