5 implants uncovered 3 days ago: dentist had to trim the gum to uncover one implant. Improvement?

Only your dentist or surgeon can really answer this question as they can compare what the tissue looks like now vs what it looked like prior to insertion of prosthesis. If the implants are integrated at this point, it is safe to unscrew the implants to evaluate the tissue. Again, defer to your dentist. 

You should be using an oral irrigator(like a water pic) to clean and remove food particles from under the denture.  Also, begin rinsing with warm saltwater( 1 teaspoon in a cup of water) for the next several days.  The swelling should resolve.  If it does not, return to your dentist to find out what is causing the problem. 

It is common to see swelling worsen in the initial 48-72 hours. Most likely starting tomorrow or the day after tomorrow your swelling should start subsiding if no infection. If tissue irritation continues after healing then your dentist can adjust the denture to fit better.
Take care

Hi:From your description it could be due to work recently done and or food particles under the denture.  Best,Dr. Maddahi