How do you fix loose upper dentures?

Reline: Loose upper dentures can usually be fixed by relining them. Upper dentures are held in place by a suction forming between the denture and gums. Over a period of time the gums will "shrink" and cause the denture to become loose. By filling in the space with new denture material (the reline), your denture will fit better.

Loose Dentures: Loose dentures need to be evaluated by your dentist. Sometimes they can be relined while often they need to be remade. While shrinkage of your gums and bone over time may be the cause, an improper occlusion (bite) is often a contributing factor for the denture dislodging, especially during eating. Even without teeth, you should be seen regularly for cancer screenings.

Reline / remake: If your dentures no longer fit, then you must see your dentist/prosthodontist to evaluate them. Sometimes they can be relined inside to fit the new tissue contours. Other times you need new ones. The normal life expectancy is 5 - 7 years, often with one reline during that time. After that the teeth wear, the bite shifts, the forces change and you accelerate the bone loss. All affect your function.

Dental lab: A good dental lab can repair dentures.

See your dentist: Dentures are a custom fit prosthesis, and over time, the gums can shrink away whereas the denture does not change, thereby causing the loose fit. Depending on the condition of the dentures, they can either be modified with a reline to make them fit better, or they can be remade.