If your denture solutions aren’t fixed in place, you shouldn't sleep with them in. Sleeping while wearing your dentures, or wearing them for too long, deprives your gums of saliva and encourages the growth of bacteria between your dentures and gum. This may lead to denture stomatitis, or oral thrush. Oral thrush is a yeast or fungal infection that can lead to:
Red or white lesions
Bleeding
Loss of taste
Sores
Inflammation
Difficulty eating and swallowing if the thrush spreads to your esophagus
Instead of sleeping with your dentures in, soak them in a glass of water or special denture solution.