Endodontics, or root canal therapy, is often the most feared and misunderstood of all dental procedures. In order to understand treatment it helps to understand the anatomy of a tooth. Your tooth consists of two main parts, the crown, which is that part of the tooth you can see, and the root or roots, which is the part of the tooth that lies beneath the gum and is surrounded by bone. Inside each root is a canal, which contains pulp (nerves, blood vessels and soft tissue.) It is necessary to have root canal treatment when the pulp becomes inflamed or infected. The most common reasons for inflammation and infection are bacteria associated with decay, very deep restorations, fractures, trauma, or periodontal disease. If pulp inflammation is left untreated, it can cause pain or lead to an abscess. In order to preserve a tooth in which this has occurred, it is necessary to remove the diseased pulpal tissue. This procedure is known as endodontic or root canal therapy.