White on gums

Since I have had my extractions, bone graft, an immediate flipper, and my dental scaling I have noticed on and off that I am experiencing a very dry mouth.
Additionally, I also notice every once in a while that I have a small amount of white film on my lower gums on both sides of the teeth that were extracted. If I rinse my mouth with water it washes away.

I use colgate advanced clean toothpaste but noticed it has whitening in it and peridex mouthwash. My dentist recommended to clean my partial with listerine which I recently started doing. Everything I read about listerine though is not that great due to the alcohol in it. I also see the whitening aspect in toothpaste may not be the greatest for those with gum problems.

Could any of these be causing this white film every so often? I was just at the dentist last week and no mention was made by the dentist of being concerned.

I am a bit worried though and hope this is not a sign of something terrible. Could dry mouth and lack of saliva be causing this?

Going to your last question first, yes, that would be my main guess as to what was causing the white marks.
It doesn't make any sense to clean your denture with Listerine, did you get a reason for doing this???
FWIW, the consensus is to clean acrylic dentures with detergent and water, then soak for 20mins or so in cold water with either Milton or household bleach in a weak solution.

Odd to find that wearing the flipper makes your mouth dry, most people complain of the opposite problem. Your brain is fooled into thinking that you're eating something and makes extra saliva to help with the "chewing"

Hi, I thought it was odd to that they suggested I clean the flipper with Listerine. I asked them repeatedly and even asked the periodontist assistant. They said the alcohol in it will kill all the bacteria accumulated on it. I think I am finding that hard to believe

I am wondering if my lack of saliva is due to stress. A lot is going on right now in my life and I noticed over the years that I get a white tongue and dry mouth when it comes to being overly stressed

The biggest problem with dentures is that they get infested with fungus, specifically Candida Albicans. If the host (that's you!) had something that lowered their resistance to infection, then the C. Albicans can get into the host, causing some fairly unpleasant symptoms. Killing only the bacteria as Listerine and other proprietary denture cleaners do (Steradent!) reduces the competition for the C. Albicans and tends to grow even more of it in the denture.

Dilute bleach kills both bacteria and fungi, so it's a far more rational choice to use to clean the denture.

Stress can lead to a dry mouth. Make sure that you're properly hydrated, i.e. drink plenty of water which would help.