The stains on teeth are mainly of three types :
Extrinsic : Extrinsic stains are surface stains. These type of stains are caused due to build up of food or drinks on the protein layer covering the enamel. These stains are normally caused due to excessive consumption of carbonated drinks, tea, coffee or tobacco smoking. They respond well to tooth brushing and regular dental cleaning.
Intrinsic : When the stains are present embedded in the tooth enamel, they are called intrinsic stains. This could be caused due to excessive use of fluoride, certain medications, trauma to the teeth or genetics can also play a role in the formation of intrinsic stains.
Age related : This is a combination of both intrinsic and extrinsic stains. Enamel wears off with age leaving the underlying already slightly yellowish dentin, to be exposed to the surface. Intake of food and drinks causes further yellowish discoloration of these teeth.
Staining by color:
Brown: Brown discoloration or brown spots may be a result of smoking or tartar formation due to poor oral hygiene. Advanced fluorosis can lead to brownish tooth discoloration.
Yellow: Tobacco chewing or smoking can cause yellow stains to develop on your teeth. Hematological diseases such as erythroblastosis fetalis can cause yellowish-green discoloration of teeth.
Black: Advanced caries or iron supplements cause black discoloration of teeth. stannous fluoride application of children’s teeth for caries prevention can also cause black stains on teeth.
White: The initial stages of caries will appear as white spots on your teeth, turning darker as the caries progresses. Enamel hypoplasia is one condition that can cause chalky white colored patches to appear on tooth contours. Fluorosis can also make the teeth appear whiter than normal.
Purple: Excessive wine drinking may cause purple discoloration of teeth.
There are several treatments available to treat tooth discoloration depending on the cause.
Bleaching: A bleaching agent such as hydrogen peroxide is used, which penetrates the dentinal tubules due to its low molecular weight. It acts by releasing oxygen free radicals and oxidizing organic pigments an chromogenic compounds.
Enamel micro-abrasion: This is a superficial approach that is effective in mild to moderate fluorosis stains, mild enamel hypoplasia, white spot lesions and in post orthodontic tooth polishing. Teeth are cleaned with a pumice slurry followed by application of an abrasive paste, typically hydrochloric acid. This depth of the stain determined the success of this treatment modality.
Porcelain veneers: deeper intrinsic stains that cannot be treated by conservative methods, need a restorative approach such as veneers. The tooth preparation required for placing veneers is minimal and is limited to enamel, to facilitate bonding to the tooth structure and also not to cause tooth sensitivity post-treatment. Crowns, instead of veneers, may be required in teeth that are more structurally damaged and require a full coverage restoration.
Tooth staining is a common esthetic concern and you should consult with your dentist to formulate a treatment plan specifically suited for your needs.