Hello sir Sometimes when you undergo RCT of the tooth, some of the hidden infections stay inside and that infection again causes that gum swelling which you are feeling. The pimple kind of thing which you must be feeling around your teeth in scientific term is called Sinus with pus drainage. You should get it rechecked asap because you should never keep any infection in your mouth as it may lead to various other systemic problems.

You might have got a re-infection in that tooth that is causing gums to swell up as inflammation. No need to panic , just consult your near br dentist again as soon as possible.

Tooth may be reinfected.get xray of tooth.if required,tooth has to be re-rctreated.antibiotics along with analgesics has to be taken to relieve pain and infection. You can consult through this for prescription of medication.

Sir sometime if you do root canal if there is more infection 2% of chance it can be reinfected so plz consult your dentist where you did root canal sir they will give a solution worst condition better to remove and replace it later after infection is subsided