A severe toothache or dental sensitivity to changes in temperature are often an indication that a patient needs root canal therapy. This treatment is recommended when decay or damage reaches the inner portion of the tooth, the pulp, where the nerve structure is housed. When dental damage reaches the nerve, it can cause severe pain. Root canals remove the damaged structure, pulp, and nerve. This tissue is then replaced with a filling material, and the tooth is resealed. This prevents the potential need for extraction, replaces lost tooth structure, and protects the tooth from any additional damage or decay.