Had metal temporary crowns on which caused a lot of pain/swell. now have permanent and pain/swell subsides, however is on/off. how long does it last?

See DDS: If you are uncertain see dentist. Many variables, excess cement not removed, need for root canal therapy, bite is high, tooth is fractured- need a clinical and possible radiographic examination to evaluate.

See DDS: If it hasn't been that long since the permanent crown was put on and biting isn't hurting I'd give it a little more time like a week or two. However, if concerned see your dentist for post-op eval.