Yes, you can wear your dentures at night, but it is preferred that they be removed. Removing your dentures at night will give your gums and bone a chance to relax from the pressure of the denture during the day. It allows the tissue to heal and encourages blood flow. If you need to wear your dentures at night, you should find time during the day to properly clean your mouth and your dentures. You should never wear your dentures 24 hours a day without preforming proper oral cleaning.
When dentures are placed the same day the teeth are extracted, it is normal to leave them in the mouth for 24 hours, even wearing them as you sleep. The dentures act like a bandage during the first day. When you visit the denturist the next day, the dentures will be removed and cleaned, sore spots relieved, and the bite adjusted. At that appointment you should have received instructions on caring for and cleaning your dentures.
In general, you should remove your dentures every night, clean them thoroughly, and place them in a container with liquid denture cleanser or water to soak overnight. This could prolong the life of your dentures by keeping them free of bacteria, and it will allow your gum tissues to rest and heal.