Although it's not impossible, it is very rare to have a reaction in your mouth like an allergy to dentures
. Dentures are made of an inert material (no active ingredients) using a heat cured process. Being allergic to a denture would be like being allergic to a tea cup or a toothbrush
After you wake in the morning try keeping your dentures out to see if your mouth continues to feel normal. It's also possible that your denture may be the indirect cause of the reaction in your mouth too. For instance, if a part of your denture rubs the inside of your lip exposing the skin, it could cause a reaction with any other substance that makes its way inside your mouth from bacteria to food or even airborne particles that you breathe in constantly. Before blaming the denture you should also rule out other oral products you use such as mouthwashes, denture cleansers, adhesives etc. all of which contain active ingredients.
You can ask your dentist about making a denture with a metal base and porcelain teeth instead of the plastic base and teeth, to see if that would help. Even tho it is rare to be allergic to the plastic, sometimes a metal base and porcelain teeth helps b/c it eliminates the plastic ingredients.
The acrylic resin contained in many dentures is called methyl methacrylate, which can, on rare occasion, cause allergies. If you ask your dentist to make a new denture made of ethyl methacrylate instead, this may solve the problem. This has worked in some patients.
There are plenty of conditions and substances to rule out before even considering the denture as the source of your problem. In the meantime you also might want to consult with your dentist and doctor. The only diffinitive test could be done by an allergist. I hope it doesn't take too long for you to discover a solution.