Most new dentures retain quite well in the mouth after insertion because the inside base of the denture closely matches the shape of your gums. However your gums have a tendancy to change shape as you age and so the longer a denture is worn, the looser it will become. Because of this most dentist reccomend that you have the denture relined by a professional at least every two years. Relining can help maintain the retention of your dentures and help protect against flabby gum tissue being produced under it. There’s three man types of denture relines: Temporary, Soft and Hard.