Most of us notice our teeth becoming darker or more yellow over time, even with good brushing habits and regular hygiene appointments. Tooth discolouration is extremely common, and understanding why it happens can help you make informed choices about treatment so, why do teeth discolour?
At Dentistry on the Grove we are always here to help, inform and advise our patients, so here is our deep-dive into teeth staining and when professional teeth whitening treatments may be right for you.
There are two main types of tooth staining: Intrinsic and Extrinsic. Each has different causes and responds differently to treatment.
Why Teeth Discolour
Intrinsic Staining: Discolouration From Within the Tooth
Intrinsic staining occurs when pigments build up inside the tooth structure itself. This can happen during tooth development or after the tooth has already erupted. Because these stains sit below the surface, they cannot be removed by standard cleaning or polishing alone, but professional whitening can often help significantly.
Here are the most common causes:
- Fluorosis
During childhood, if teeth are exposed to excessive levels of fluoride as they develop, fluorosis can occur. This can appear as white, chalky patches or darker brown mottling. Although fluorosis marks cannot be polished away, whitening can often reduce the contrast between the affected enamel and the surrounding tooth, making the overall appearance far more uniform and pleasing.
- Antibiotics
Some antibiotics, particularly tetracycline and minocycline, are known to cause deeper staining. They can create blue-grey or brown banding across the teeth, depending on the duration and timing of their use.
Because these stains are very deep, whitening usually requires more time and may need to be combined with cosmetic treatments such as bonding or veneers for the best result.
- Family History and Genetic Conditions
Certain inherited conditions, as well as environmental factors, can affect the formation of enamel or dentine, making teeth appear discoloured from a young age.
- Trauma
Trauma is one of the most common causes of intrinsic discolouration. When a tooth suffers an injury, the pulp (the inner nerve and blood supply) can become inflamed and bleed into the tiny tubules within the tooth.
This causes:
- An initial pinkish hue
- Followed later by a darker grey or black colour as the haemoglobin breaks down
Fortunately, this type of staining often responds very well to treatment. After a root canal, internal whitening can significantly brighten the tooth from the inside out.
- Ageing
Ageing naturally changes the colour of our teeth. Over time:
- Enamel (the hard, whiter outer layer) gradually wears away
- The underlying dentine, which is naturally more yellow, becomes more visible
- Secondary dentine builds up within the tooth, often taking on a darker tone
These changes combine to give older teeth a more yellow or dull appearance. Whitening can be highly effective in brightening age-related discolouration.
- Staining Caused by Dental Treatments
Certain dental materials can also cause intrinsic staining. In these cases, whitening or restorative treatment may be recommended.
Extrinsic Staining: Surface-Level Stains
Extrinsic stains are far more common and affect only the outer surface of the enamel. They are caused by pigments attaching to plaque or settling into the microscopic cracks and grooves of the teeth.
Typical culprits include:
- Coffee
- Tea
- Red wine
- Smoking and vaping
- Foods with strong pigments such as berries, turmeric or tomato-based sauces
Many extrinsic stains can be removed during a routine hygiene visit through professional cleaning and polishing. However, once the pigments settle deeper into the enamel surface, brushing and polishing may not be enough, and this is when whitening treatments become helpful.
How Whitening Helps
Professional dental whitening is designed to penetrate the tooth and break down pigment molecules safely and effectively. The products we use at Dentistry on the Grove are from Boutique Whitening, who have created one of the purest and most trusted whitening gels in the world, that are only available via dental practices. Coming to us for professional teeth whitening treatment and having it done under the supervision of our dental team, means we can use more effective and longer lasting whitening agents than anything you can buy over the counter.
Boutique Whitening can be effective in lightening both extrinsic and intrinsic stains, and at Dentistry on the Grove, we will be happy to consult with you to identify the type of staining you have, advise whether whitening is suitable and which of the Boutique Whitening products will be most effective for you. So, now you know why teeth discolour, would you like to book a patient consultation?
