• Intrinsic stains
• Extrinsic stains

Extrinsic stains are those that deposit on the surface of the teeth but can be easily removed by a dental polished and are produced by chromogenic bacteria, food, snuff, by the profession or iatrogenic. On the other hand, in the intrinsic ones there is a pigmentation of the inside of the tooth and they cannot be eliminated, but they can be camouflaged so that the most pleasant teeth are not visible and look. Extrinsic stains are produced by several substances, which are mainly classified into two: primary and secondary chromogens. Primary chromogens are all those that bind to the dental plaque of the teeth through hydrogen bonds. In their initial form they can be eliminated by means of a good brushing technique but if they are fixed it is necessary a professional cleaning and the use of abrasive pastes. The primary chromogens can be coffee, tea, red wine, tobacco nicotine and sugary drinks. Secondary chromogens are substances that are converted into chromogens by chemical reactions, also called iatrogenic. The extrinsic stains produced by this type of chromogens make the surface rough and can retain more bacterial plaque. Most of these substances are in dental rinses, such as chlorhexidine or tin fluoride. The dyeings or intrinsic pigmentations are color changes that occur within the dental tissue is affected when the enamel and / or dentin. This type of pigmentation can be local or general cause.

Those of local cause usually affect the dentin of one or several teeth and are due to dental pathology (caries, necrosis, and hemorrhages due to trauma or pulp degeneration), fractures, iatrogenesis (an inadequate opening in an endodontic tooth, the endodontic material, among others) or fillings with amalgam or gold. General cause stains affect the dentin of all teeth and are due to excessive intake of fluoride during development (fluorosis), tetracyclines or systemic diseases. Fluorosis is the consequence of excessive intake of fluoride during the development and calcification of tooth enamel. The degrees of dental involvement are related to the concentration of fluoride absorbed. Doses greater than 1 ppm in drinking water can produce fluorosis. Fluorosis can be classified into three: simple fluorosis (if there are white or brown spots on the smooth surface of the enamel), opaque fluorosis (when the spots in the enamel give it a dull appearance) and fluorosis veined (where there is a loss of substance and exposure of dentin). Tetracyclines constitute a group of antibiotics that cross the placental barrier and are excreted in breast milk, therefore, temporary dentition can also be affected. These types of antibiotics are fixed to the teeth and bones due to their affinity for calcium. The effects of tetracycline depend on the dose, the duration of treatment, the type of tetracycline and the time it has been ingested. This is why there are 4 degrees of staining: grade I (minimal involvement with brown coloration on the surface), grade II (darker coloring), grade III (presence of horizontal bands of dark gray or deep yellow) and grade IV (involvement of the entire crown with a very dark coloration).

HOW TO REMOVE STAINS FROM TEETH?

Extrinsic stains can be easily removed, but depending on the state they are in, the treatment is simpler or more complex. Stains with an initial stage of adhesion can be easily removed by a good tooth brushing technique, however in a medium state complementary methods are necessary with the use of abrasive pastes to effectively remove the chromogen. Finally, if these stains are in an advanced stage, professional dental prophylaxis is necessary. In order to eliminate intrinsic stains it is necessary to use more specific procedures. The use of teeth whitening can be performed both on a vital tooth and on a non-vital tooth to improve pigmentation. If there is an advanced degree of pigmentation it is necessary to resort to alternative therapies, some of these could be the use of veneers or porcelain facets and even the use of crowns of total coating if the involvement of the pigmentation is of the entire crown of the tooth.  In order to know the most appropriate therapy, it is essential to conduct a study of each case and analyze the type of staining in order to offer a more individualized treatment.