I had a root canal to put on a dental cap on my lower lateral incisor for cosmetic reasons. The tooth was perfectly healthy prior the treatment but every since the root canal the tooth has been very sensitive to pressure that I can't even touch it with pain and I can't even take a bite with it. I had visited my dentist several times and she said there was no infection and slight soreness is expected post root canal treatment. But it's been nearly 7-8 months and it's still just as painful as day 1. Now I regret even getting the cap. What could be the reason for this pain? And how do I cure it?