dental clinic near keelkattalai How do you know if you need a root canal? Root canals are needed for a cracked tooth from injury or genetics, a deep cavity, or issues from a previous filling. Patients generally need a root canal when they notice their teeth are sensitive, particularly to hot and cold sensations. There are a few symptoms that mean you might need a root canal- Severe pain while chewing or biting Pimples on the gums A chipped or cracked tooth Lingering sensitivity to hot or cold, even after the sensation has been removed Swollen or tender gums Deep decay or darkening of the gums