When you have complete dentures, they need to be checked periodically and have a denture reline from time to time, as they become loose. There are health effects of a loose denture. If they go for too long without proper care, the soft tissue begins to overgrow in folds under the denture and around the rim. There are cases where surgery may be required to to remove this excess tissue. Sometimes, however, the tissue overgrowth can be healed easily with tissue conditioner treatments from your dentist.
There are various types of denture relines available. They can be done in the office or sent to a dental laboratory. They can be either hard or soft. The advantage of the in-office treatment is that you don't have to be without your teeth for the day or two that would be required of laboratory processing. In-office reline materials have improved somewhat over recent years. Light-cured materials have been developed that are more durable and longer-lasting than the old chemical-cure materials.
And soft denture relines are more comfortable than hard ones, though they are more expensive and less durable. Read our page on that subject, linked in the first sentence of this paragraph, to learn more about their pros and cons.

A home kit
There are also home denture reline kits available. We recommend them only for temporary fixes, because, as mentioned above, if this procedure isn't done properly, it can cause difficult-to-treat soft tissue problems. If money is an issue, we would advise you to shop around to various dental offices. This procedure is fairly straightforward and within the abilities of every dentist, and you are better off in the hands of a cheap dentist than trying to do it yourself.