Question

After every glass of red wine, my teeth and tongue become discolored. How can this be explained? What do I have to do to prevent this discoloration from occurring in the first place - apart from not drinking red wine? H. R. in C. 

Short answer

Our oral fluid contains many different substances, including proteins and bacteria. This layer of proteins and bacteria can absorb dyes. Depending on the thickness of this layer, visible discoloration can occur within minutes. However, this discoloration can be removed immediately with a thorough tooth cleaning as long as this layer is not yet calcified.

Red wine, as well as coffee and tea, contain colorants that can stain other substances. When we drink such beverages, they come into contact with the surfaces in our mouth, including our tongue and teeth. 

Whitening teeth 

How do the individual surfaces behave in the mouth? 

The healthy natural tooth substance, which consists of hard enamel, will not become discolored or only very slowly over many years. If this discoloration is disturbing (the dyes have penetrated into deeper layers of the tooth), the teeth can be lightened with bleaching. This procedure is harmless and usually very successful. 

Artificial tooth structures, especially plastic fillings that have become discolored, cannot be bleached. If professional polishing does not help, they will have to be replaced. Porcelain surfaces for crowns, veneers or fillings have the advantage that they do not discolor. 

Proteins and bacteria 

Our oral fluid contains many different substances, including proteins and bacteria. All natural and artificial surfaces of our teeth are always covered with a layer of protein (pellicle). Even after a perfect tooth cleaning, this protein layer forms again within minutes. The bacteria will also adhere to the tooth surfaces within a few hours and, if they are not disturbed by regular tooth brushing, will grow into a thick bacterial layer and calcify (tartar) within days. 

Clean teeth thoroughly 

This layer of protein and bacteria can also absorb the dyes described above and, depending on the thickness of this layer, visible discoloration can occur within minutes. However, this discoloration can be removed immediately with thorough tooth cleaning as long as this layer is not yet calcified. It is therefore best to clean your teeth thoroughly two to three times a day, and at least once a day between all teeth. This prevents visible discoloration from occurring in the first place. 

The surface of the tongue is keratinized to different degrees in different people. It is these keratinized parts that can easily become discoloured and even make the tongue appear black. The solution here is also to clean the tongue daily with a toothbrush or a special tongue scraper. 

Author: Dr. med. dent. Jürg Eppenberger
Published in: Neue Luzerner Zeitung on March 15, 2006