Heat cure acrylic resin upper denture problem. do i have to go back to the original dentist?

Not Necessarily: If you have a denture problem, it's generally best to see the original dentist again. Not only is he/she most familiar with your specific case, but he/she probably won't charge as much to perform follow-up work on something he/she fabricated. A new dentist is okay too, but it may cost more. If your original dentist can't help you, then you'll have to find someone else, obviously. Either way is ok.

Depends: If you are having a problem that your current dentist cannot solve, see a prosthodontist. They are the specialists trained in dentures. Many in your area.

No: Go to whom you're most comfortable with. The original dentist may be fine and quite able to do this for you. Otherwise, you may visit any dentist of your choosing. Depending on the problem, your denture may be able to be fixed right in the dental office, or it may need to be sent out to a dental lab to be fixed. Keep smiling.