The root canal is needed when the nerve of a tooth has become damaged by injury or infected by decay. This procedure saves the tooth and can help restore it to natural function. For the first step of this procedure, your doctor numbs the area and then creates an opening in the tooth to access the root's interior. Your doctor will then remove the infected tissue and flush and clean the area. Next, the root is filled with a special sealing material, and the opening is filled and sealed. The tooth has been saved and restored to its natural function.