Discoloured Teeth
In this section, we will cover:
- What are the causes of discoloured teeth?
- How can I stop my teeth from discolouring?
- What are the treatment options?
What are the causes of discoloured teeth?
In general, dentists will classify discolouration into 3 separate categories. This helps to determine which treatment options are appropriate to manage your discoloured teeth (if you wish).
The 3 categories are outlined below:
Extrinsic Discolouration
This occurs when the enamel (outer layer of the tooth) picks up stains from foods and drinks we consume. Common culprits include: tea, coffee, red wine and cola. Smoking also causes extrinsic staining due to the tobacco.
Although not technically a form of extrinsic discolouration, poor oral hygiene can also cause your teeth to look discoloured due to the build up of calculus (or tartar).
Instrinsic Discolouration
This type of discolouration is rooted deeper within the tooth.
It is usually caused by:
- developmental defects (see dental anomalies)
- too much fluoride consumption whilst the teeth are developing (fluorosis - LINK)
- certain antibiotics (e.g. tetracycline) taken before 8 years old
- nerve damage (commonly due to dental trauma)
- dental braces (white spots due to demineralisation under and around the metal)
- untreated tooth decay
Age-related Discolouration
Our teeth are made up of multiple layers. The white outer layer is called "enamel" and just under this is the yellow "dentine" layer (see basic tooth anatomy).
As we get older, our teeth begin to look more yellow. This is normal. It happens to everyone. But why?
- Dentine continues to form throughout our life. As more dentine is laid down, the middle layer of our tooth becomes yellower and darker.
- The enamel wears away and becomes thinner. The underlying dentine shines through and the tooth looks more yellow.
How can I stop my teeth from discolouring?
Simple tips to keep your teeth from staining:
- limit the amount of "staining" foods and drinks
- don't smoke or chew tobacco
- brush your teeth twice a day to remove surface stains and prevent a build up of calculus
- use an age-appropriate toothpaste and spit the toothpaste out (don't swallow it)
Intrinsic discolouration is not always preventable. This is the case for certain developmental defects.
Following dental trauma, the nerve of the tooth can become irreversibly damaged. When this happens, the tooth can turn grey/brown. Starting root canal treatment sooner rather than later can help to avoid this discolouration. In some cases, a tooth can still discolour after having root canal treatment.
What are the treatment options?
- Scale and polish
This can help to remove extrinsic stains from the teeth. If there is only some light staining on the teeth, this will often be enough to get a nice result. For heavier staining, you may benefit from further treatment such as tooth whitening. - Microabrasion - LINK
This involves gently removing the surface layers of the tooth in tiny amounts to remove very superficial intrinsic stains. This procedure often requires multiple appointments before the ideal result is achieved. It is useful for some cases of intrinsic discolouration, such as fluorosis and hypomineralisation (LINK). - Resin infiltration
This technique is useful for managing white spots of discolouration. A runny tooth-coloured resin is used to fill the tiny microscopic pores within the discoloured area and make it look more similar to the surrounding tooth. This will not always completely mask the discolouration. - Teeth whitening
Teeth whitening can be tailored to treat the whole mouth or a single discoloured tooth, depending on your concerns. It uses a bleaching agent to lift stains from the tooth. It is useful for most types of discolouration.
Legally, this should only be completed by a registered dental professional. There are certain rules we must follow when whitening teeth to ensure your safety.
"Home whitening" kits advertised online or whitening at your local beauty salon are unsafe and illegal. They can burn the soft tissues in the mouth. - Restorations
If the above treatments fail, you may benefit from a composite restoration or dental veneer to mask the discolouration. Where possible, it is best to avoid these treatment options as they irreversibly damage the teeth and you have to maintain/replace them for the rest of your life.