The formation of stains on teeth is a problem that is faced by more or less every person at some time or the other. Even people who claim to have impeccable dental health, often fall victim to discoloration. This problem can be of two types, that is, intrinsic and extrinsic staining. Intrinsic Staining Causes Intrinsic staining is when the cause is an internal factor, i.e., the stains are not merely on the surface of the tooth. Caries and Tooth Decay Dental caries, or as it is commonly called, tooth decay, leads to intrinsic staining, which causes black spots on the teeth. Tooth decay causes damage to the enamel and the general tooth structure, and one of the initial cavity symptoms is black discoloration on the surface of the tooth. This is because the decay is caused by chromogenic bacteria, especially the Actinomyces species which produce hydrogen sulfide. The sulfide reacts with the saliva to produce ferric sulfide, which is visible as black spots on teeth. Sometimes, the discoloration, may actually be internal, but it can be mistaken for black spots, as is seen in a tooth that has undergone root canal treatment. Even a chipped tooth, or any kind of severe trauma to the tooth may lead to necrosis (death) of the pulp, which may be wrongly diagnosed as black spots on teeth. Fluorosis Fluorosis is a condition where stains are seen due to drinking water that has very high fluoride levels. This water usually has more than 1ppm (part per million) of fluoride content, which causes white stains on teeth, along with flaking. If the level of fluoride is not brought down, the teeth start mottling, and there is brown staining seen, with progressive degeneration of the tooth structure. Side Effects of Drugs Sometimes, an expectant mother may suffer from an infection, due to which she needs to take certain drugs, which have the side effect of causing black spots on teeth. One such notorious drug is tetracycline. Ingestion of tetracycline impairs the fetal dental development, and causes intrinsic dental staining, which is seen as black spots. Dental Restorations Sometimes, amalgam restorations can also cause intrinsic staining, which occurs when their corrosion products leak, causing stains on teeth, especially around or near the gingival margins. The corrosion products produce a grey-black hue around the silver filling. Sometimes, the stains may even appear in cases of long standing tooth colored restorations, like stained composite binding restorations etc. Hereditary Abnormalities There are certain hereditary abnormalities, like dentinogenesis imperfecta and amelogenesis imperfecta, where the tooth structure is weak right from birth, due to ill-formed enamel or dentin. Due to the fragility of the tooth structure, there is increased susceptibility to flaking and staining. Although this condition is relatively rare, it is a very difficult disorder to treat, and involves a very long-drawn treatment plan. Extrinsic Staining Causes Extrinsic staining is when there is stains on the surface of the teeth due to an external factor, which makes such cases relatively easier to treat. Caffeine Caffeine and its related products, lead to teeth stains. Coffee and tea, especially coffee, have high levels of caffeine. The plaque layer that is present on the surface of the teeth gets stained while drinking coffee, which leads to extrinsic coffee stains, that can be treated easily. However, sometimes, people that are addicted to caffeine products, like tea, may get tea stains on teeth over a long period of time, which is more difficult to treat. People that have had tooth colored restorations done, especially on their front teeth, are at greater risk. Smoking and Tobacco Chewing Smoking and chewing tobacco causes the staining of teeth in the same manner as that of coffee and other caffeine products. Chewing tobacco causes many side effects, like burning in mouth, attrition of teeth and staining. Medication Side Effects Intake of certain drugs, like excessive intake of liquid iron supplements, which are often prescribed to anemic patients, leads to extrinsic staining, which manifests as black spots on the teeth. This is because the metallic compounds interact with the dental plaque present on the surface of the teeth, leading to staining. It maybe a result of an occupational hazard, as it is also seen in cases of people that are excessively exposed to industrial iron, silver and manganese. Even excessive use of certain mouthwashes, like mouthwashes that contain silver nitrate or potassium permanganate, can also cause black spots. Intrinsic Staining Treatment The treatment of intrinsic staining is not easy, as the cause is quite complicated and nearly irreversible. For people who have staining due to caries, the decayed portion can easily be removed and replaced with a filling. However, for cases where the staining is due to a very old root canal treated tooth, bleaching could be of help. For fluorosis and other hereditary problems, a long and detailed treatment plan needs to be chalked out, as it varies from case to case. Extrinsic Staining Treatment Getting rid of stains when it comes to extrinsic staining is relatively easier. The person will need to go to the dentist and get a proper clean up done of his teeth. The stubborn stains may require ultrasonic scaling. However, for all those caffeine addicts, the intake of coffee and tea will have to be cut down, so as to assure that the problem does not recur, nor aggravate. Thus, the intrinsic and extrinsic tooth staining problem has baffled dental practitioners all over the world. However, with regular dental care and routine dental check-ups, such problems and their complications can be kept at bay. Disclaimer: This article is for informative purposes only, and should not be used as a replacement for expert medical advice.