Tooth 18 has been moderately painful to biting pressure on back half only for 4 years. often times there's mild ache. no gum pain. tooth/gum abscess?

Evaluation: The tooth in question needs to be physically evaluated, and together with a radiograph your local dentist will determine if there is a cavity, a fracture, or even an abscess. After four years it's time to see a dentist.

See your dentist: It is an indication for periodontic involvement and root canal is possible. See your dentist for x-ray, evaluation and treatment.