The longer dentures are worn the more your gums change underneath the denture. A result the denture can become loose and begin moving over gum tissue possibly creating sores throughout the gum line. Therefore a denture should be relined every two years in order to restore the retentive qualities of the denture and prevent production of flabby gum tissue underneath and sore along the gum line. There are three (3) types of relines: Hard, Soft and Temporary.
Hard relines are performed on all dentures every two years. Essentially the denture is reshaped to conform to the contours of your mouth maximizing tissue contact which in turn produces maximum suction.
When patients can not wear ordinary dentures because of tender gums, the denture can be relined with a material that remains somewhat pliable for a year or two before requiring replacement.
Patients who have neglected their dentures for long periods are always subject to red, swollen and misshaped gums, making it impossible to take an impression of them for a new denture. In cases like this, the dentist will frequently resort to a medicated reline material to allow the inflammation to subside. After a few months the patient is ready for his new denture or hard reline.
Rebasing the denture is similar to reline except the denture comes back with all the pink plastic above replaced. The only parts of the old denture that remains after a rebase are the teeth. A rebase is usually done when the denture has multiple cracks or repairs and does not fit well, but the teeth themselves are still in good condition and fit correctly with the teeth in the opposite arch.
As dentures age they become more prone to breakage. With age the fit becomes looser allowing the denture to rock while it is worn. Repetitive flexing weakens the plastic and eventually it breaks. Additionally this flexing can cause the teeth in the denture to loosen and break out. If your denture breaks bring the pieces to your dentist, do not attempt to fix them yourself. Only a trained specialist will be able to ascertain whether or not they can be fixed and how they can be fixed in order to perform without causing damage to your mouth.