After a crown my child's gums are swollen and inflamed, how will i know if they are infected?

Go back: Call your dentist to have the crown and the gums checked. You can't tell, you need your dentist to examine your child. The tooth may be infected, the crown may be irritating the gums, there may be an allergic reaction, etc. In all probability this is just a local reaction to the irritation of having work done, but call your dentist to have it checked. You'll be glad you did.

See dentist: Swelling and inflamed gums are two signs that they are infected. You need to return your child to the dentist and find out why and have it treated.