Root canal therapy: Tooth is made out of 3 layers, enamel, dentin and pulp.  When the pulp, also known as the nerve, becomes inflamed and infected due to decay, crack, or injury, when the tooth is left untreated, it can cause extreme pain and abscess.  If a tooth is not treated with root canal, the tooth might need to be extracted.  Signs that indicates needing Root canal treatment include constant pain, prolonged sensitivity to hot and cold, tenderness to touch and chewing, and swelling, however, sometimes there is no symptoms.  Root canal therapy helps to save many teeth so most patients are able to restore function, and smile.  The aim of the treatment is to remove all infection from the root canal. The root is then filled to prevent infection recurring. Root canal treatment is a skilled and time-consuming procedure, sometimes it requires two or more visits, and sometimes, the treatment maybe completed on the same day with a final filling placed.