hello sir..    you need to get IOPA (x-ray)  of the involved tooth to rule out the cause.... As you did not mentioned when the root canal treatment has done... If the treatment has done recently , gum inflamation may be due to  over instrumentation of canal or over filling of canal(Extrusion of Gutta percha periapically) if the treatment has done long back then it may be due to Re_ Infection of canal.... It may be a simple gum inflamation due to plaque and calculus deposits sub gingivally... Treatment depends on cause

As u mentioned Ur problem..it's likely to be due to an infection in your canal of that tooth which you do RCT .. A clinical examination will better illustrate problem. Or It's may be due to gingival infection.. Better to visit nearby dentist

Hi, it seems u have undergone a recent rct treatment, if yes, then  swollen  gum can be because of an overhang in the  filling of your tooth, which means a small portion of the filling might be extruding in to the gum, which might cause that localised swelling. Pls visit the dentist  for chk up and  correction if needed.

You haven't told when rct has been done for that tooth.swelling can either be due to gum infection or becoz of infection left in that rct treated tooth. Sometimes it can be due to adjacent  infected tooth .

your tooth is root canal treated recently   or  before  ?there is possibility of infection  with that tooth .or next to that tooth . may be truma to gum near that tooth can give swelling visit a dentist .good  clinical examination is necessary

Hi .It can be only gingival inflammation.

Seems like re infection.

Get the tooth X-rayed. It could be a reinfection of the root canal or a gum infection. Treatment depends on the cause