RCT in children is called Pulpectomy. It is a safe procedure and is best done by a qualified Paediatric Dentist.
There can be various reasons for the swelling such as pressure buildup in the canal of the tooth, or due to reaction of the local anaesthetic used for the procedure, or due to prior infection which will take time to heal with the help of antibiotics or incomplete removal of pulp tissue from the tooth canal or residue left from irrigation of canals.
Next Steps
Refer to a Paediatric Dentist and check the reason.
Health Tips
Trusting your doctor is important and following proper instructions goes a long way.