Full dentures, to replace all your own teeth, fit snugly over your gums. They will help you to eat comfortably and speak clearly, and will improve your confidence and self-esteem.
Partial dentures replace teeth that are missing and can sometimes be supported by the teeth you have left. If you have gaps between your teeth, then your other teeth may move to take up some of the space, so you could end up with crooked or tilted teeth. This could affect the way you bite and could damage your other teeth.