The tissues and bones of your mouth may shrink (atrophy) with the passage of time or with the gain or loss of body weight, causing a change in the fit of your dentures. A simple reline may help them fit snugly again. However, if you've worn your dentures for a number of years, or the bases are too far out of shape, it may be time for replacements. It is counterproductive to use more denture adhesive to try to make them hold better, because this may lead to faster bone loss and additional problems with the fit of your dentures.