Dentures when not in use are kept in water. how to keep them in sterile condition, what to do?

Denture care: You can't sterilize your mouth and you don't have to sterilize dentures. See a dentist to have them professionally cleaned and keep them in a solution of polident or efferdent overnight. Discuss with your own dentist if they need further disinfection or perhaps replacement.

Anti-bacterial: Definitely keep the dentures in CLEAN water when not in use one of many anti-bacterial powders/cleaners that you add to the water. Never boil or microwave (yes, that has been done.) If sick, flu, etc. always place the dentures in cleanser every night.