My pre molar feels tender after having a chewy sweet. i have had root canal on this tooth few years ago if that helps. slightly hurts when biting down?

Needs evaluation: Tooth may have a fracture, a recurrent infection, or even periodontal bone loss. Please call your dentist for an appointment.

See DDS: Have the dentist evaluate the area to make sure that the crown, if your have a crown, is not loosened or that the tooth is not fractured.

Pain: Pain is your body's way of telling you there is something wrong. May have failed root canal treatment. If tooth needs retreat net, best done by a root canal specialist, an Endodontist.