Probability of such persistent pain may be due to several reasons, do post an x-ray for an opinion.

Hi...seven sittings is high enough if u r still havin acute pain..pain may be cause of another pulpaly infected tooth, or a missed canal in the ongoing treatment.. ne how if u can post ur x rays here wil be of great help to comment..best is if u feel take second opinion from an endodontist best of luck take care

Any pain should subside once v start root canal. If it is not subsiding means there is chance 1. that some tissue is left inside canals 2..over extension of the files beyond roots 3.the temporary cap might b high 4.there may b some other adjacent tooth which might b decayed as well.. Consult a endodontics r a senior practioner All the best

There is nothing wrong with a dentist taking 7 or more visits for a root canal. But if there has been no significant improvement in pain since you started your treatment then you should go for a second advice.