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That depends-- some white films are normal, and some are not. Assuming that this white film is a phenomenon that represents a change from the usual and former condition of the tongue, this could not be considered normal.
Some white films are the result of either increased growth of the surface layer of tissue-- the epithelium-- in response to a chemical, thermal or physical irritant. For example, some mouthwashes, toothpastes, or chewing gums contain ingredients that can either irritate the tissues or provoke a contact sensitivity
reaction, so if you've recently begun to use a new oral product, or habitually burn your tongue with hot beverages, this could be the culprit. Sometimes the surface epithelium can thicken-- rather than from accelerated tissue growth, but due to a reduced rate of tissue exfoliation, as might happen when the mouth is dry due to mouth breathing or from using medications that impair salivary secretion. These conditions are common during, for example, the active stages of an upper respiratory infection
, when mouth breathing due to nasal obstruction and mouth drying medications are frequently used.
In addition to thickened surface epithelium, your description could also suggest an oral yeast infection, or "thrush"-- this is especially the case if the removal of the white film leaves a reddened or bleeding tissue surface. Thrush represents an "opportunistic infection-- a condition that is more provoked by local conditions than from any kind of contagion. Issues that may cause thrush include sustained antibiotic use, diabetes, or immune suppression due to medications or disease. Management of thrush involves the use of antifungal medication, and management of the underlying condition(s) that gave rise to the infection.
In any case, if the white film on your tongue does not resolve within a week or two, you should arrange for a diagnostic session with your dentist
. Once the nature of the film has been identified, it will be possible to determine its significance, as well as an appropriate management approach.
Hope this helps...