“How long does pain and swelling last after dentures?”

If you are new to dentures and had extractions before the immediate placement of the dentures then an adjustment may need to be made soon, with anti inflammatories swelling will subside in a few days, healing will proceed dramatically over 7-14 days; frequent relines will help the fit and speed healing further; complete healing (bone) in 6 months. If no extractions but just new dentures then need to relieve any high spots (inside) and check / adjust the bite for stability-

It sounds like you had extractions done at the same time as your denture was inserted. In that case, the pain is due to surgery and should subside within 7 to 10 days. Immediate dentures are fabricated ahead of time and they never fit well. As soon as your gums heal, you should have them relined. 

Dentures are a change in your lifestyle, but should not be painful. A little discomfort can be anticipated when you have an immediate denture right after multiple teeth extractions. Most of the dentures need adjustment within 3 weeks after delivery. Dentist appointment is advised to solve your problem.

Monika Tyszkowski, DDS