Stained teeth occur for different reasons, and therefore have different treatments.
These are stains on the external part of the tooth.
Stained by food or drink
The colourants in coffee, tea, red wine, nicotine and some very dark kinds of food, like liquorice or squid ink, if eaten very often, can sometimes stain the teeth. Using chlorhexidine mouthwashes or taking iron-based medicines can also give them a darker appearance.
As well as your natural teeth, the above also stain fillings and crowns, whether in porcelain or resin.
In cases like these, brushing your teeth three times a day and having your teeth cleaned at the surgery once or twice a year, as required, can prevent or control staining. You can use whitening toothpastes, provided that they are of good quality, given that the highly abrasive versions can scratch the enamel of your teeth and allow colourants to seep into the ridges this creates, making them more difficult to remove.
The cleaning process involves flakes of rubber which gently polish the tooth, giving it a shine but causing no wear.
Removing the colourant, or reducing its effect, is the best way to reduce staining. With tobacco, the best idea is to smoke less, although for improved dental appearance stopping is the best remedy. If you can’t stop, a good whitening toothpaste will help enormously.
Coffee or tea, if frequently consumed, are preferable when diluted with milk. This will reduce staining.
Mouthwashes or toothpastes with chlorhexidine are excellent disinfectants, and we frequently prescribe them after implant surgery, tooth extractions or gum inflammations, but always for a short period of time ranging from a few days to two or three weeks. After this time, if discolouration occurs, having your teeth cleaned at the surgery will return them to their natural colour. The discolouration is greater in patients who smoke or have very thick saliva.
Resulting from issues with the enamel
Sometimes white or brown stains occur due to congenital malformation of the enamel. In this case the tooth actually grows in with the poorly formed enamel.
If the stains are very superficial, microabrasion or lightly filing the tooth surface will make the stain disappear.
In the case of deeper stains in the malformation, drilling will be required, in the same way as for tooth decay. The area will then be covered with a composite filling in the same colour as the tooth.
This is when the tooth looks darker due to internal discolouring of the tooth itself.
Sometimes old metal fillings darken the tooth from the inside. In normal cases, changing the filling for a composite filling in the same natural colour as the tooth is sufficient. However, in the case of front teeth this system may not be enough in itself and a porcelain veneer or even a crown may be required.
Discolouration due to endodontics
On some very few occasions, the devitalised tooth (endodontics) may darken to the point of being noticeably different in colour from those around it. In this case we will whiten it internally, making it look much more natural. See this technique in the article on whitening.
Discolouration due to tetracyclines
Tetracyclines are excellent antibiotics, but if given to children under the age of 7 they may cause tooth discolouration.
This is the age when the teeth are growing within the jawbone meaning that, if tetracycline settles in them, the dentine will acquire a darker colour, typically visible in stripes.
This often happened to children born in the late 50s, the 60s, and even sometimes in the early 70s. The shades vary in intensity, with some patients showing slightly darker teeth, while others are rather grey, or display brownish or even purplish shades.
In less serious cases, external whitening is sufficient; however, some of the more intense cases require the fitting of either porcelain veneers or of zirconia-porcelain or metal-porcelain crowns to conceal the dark shade of the tooth.
Read more about porcelain veneers and crowns.