A soft denture liner is placed in the part of a denture base that contacts tissues. This provides comfort for those persons experiencing considerable pain while wearing a denture that has a hard plastic interface (the inside of the denture).
These individuals may have a low threshold for pain, and/or the gum tissue that overlays jawbone is usually thinner than normal and does not resist pressure well. When such tissue is compressed between hard jawbone and hard denture plastic, pain is easily elicited. Replacing one of these hard interfaces with a soft denture liner helps eliminate or reduce this painful tissue compression.
Denture liners are usually fabricated from special medical grade rubber or silicone-type compounds. The silicone materials are generally more compressible and, consequently, softer.
In order for these materials to function adequately, they must be reasonably thick. Therefore, the amount of plastic that needs to be removed from the inside of a denture to allow room for these liners may weaken some dentures. In those cases, it becomes necessary to incorporate a reinforcing metal framework within the body of certain dentures. There are several steps involved in installing a soft denture liner, such as impressions and various laboratory procedures.
Soft denture liners tend to continually harden, though a patient may not be aware of this happening because the process is gradual. However, they eventually will begin to have increasing problems until a new soft denture liner is placed.
Denture liners are porous in nature, which accounts for why they are soft. However, this porosity contributes to their deterioration and collection of microorganisms.
If a soft denture liner becomes contaminated with disease-causing microorganisms (a fungus for example), it may not be possible to decontaminate the denture without having to replace the denture liner.
Persons with dry mouth usually have difficulty wearing dentures due to pain and irritation caused by the hard denture surface rubbing against underlying tissues that are not lubricated with adequate saliva. While soft denture liners would appear to be ideal for such individuals, they are generally much more difficult to maintain. Because impaired saliva production allows a very significant collection of microorganisms to buildup in the mouth, this usually results in unacceptable contamination of porous soft denture liners unless meticulous oral hygiene is maintained.
While denture liners generally will last longer than a year, they should be replaced on an annual basis or sooner. The frequency of replacement depends on each situation and the patient's oral hygiene.
by Joseph J. Massad, D.D.S.