How long does it take for swelling in bridge to go down?

Swelling: If there was some slight swelling of the gums around the bridge this should go down after a day or two. Rinsing with warm salt water (1 teaspoon of salt in a liter of water is sufficient). If the swelling is more severe and lasts for longer periods then you should have a dentist examine you for possible infection of the tooth underneath or your gums may require some other form of treatment.