Severe, persistent tooth pain, sensitivity to heat, swelling on the gum and pain when touching or biting down on a tooth are symptoms that indicate the potential need for a root canal, according to DentalCareMatters.com. The indicated tooth may also appear to be darker than other teeth.
Tooth pain severe enough to interrupt sleep or pain that persists long after the removal of hot or cold substances indicates a possible need for root canal therapy, notes WebMD. Swelling associated with an infected tooth may radiate out to the ears, head and neck in addition to occurring along the gum line. A persistent or recurring pimple on the gum may also be present when a root canal is necessary. However, teeth in need of root canal therapy may also be symptom-free, according to DentalCareMatters.com.
Root canal therapy repairs a badly decayed or infected tooth, explains WebMD. Dentists use percussion testing, thermal testing and an X-ray evaluation to confirm the need for root canal therapy, according to Animated-Teeth.com. Electric pulp testing can also determine the vitality of the nerve in a symptomatic tooth.
Dentists remove damaged tooth pulp and nerve tissue during root canal therapy, reports WebMD. They then clean and seal the inside of the tooth. Infections and abscesses in surrounding tissue may occur if teeth with damaged tooth pulp and nerve tissue do not receive treatment.