Many people notice a change in the colouration of their teeth with time. There are different factors that can result in stained teeth. Understanding the type and colour of teeth stains can help you in seeking the right treatment.
It’s important to note that stained teeth don’t always present an aesthetic problem. They may be indicative of an underlying health problem and be symptomatic of a larger problem. In many cases, it is possible to prevent your teeth from getting stained.
What Are Stained Teeth?
Tooth staining or discolouration occurs when strongly pigmented chemicals (chromogens) stick to the enamel or deeper layers of the tooth. Substances like tannins, found in teas and coffees, make it easier for chromogens to stick to the enamel. They increase the likelihood of staining.
Depending on the cause of tooth discolouration, you may have yellow, brown, grey, black, green, orange or white stains. Keep in mind that your genetics play a role in determining the colour of your teeth. Many people have naturally whiter and brighter teeth. Also, according to a study published in the British Dental Journal, generally, canine teeth are darker than the central and lateral incisors.
Our teeth have also what’s known as the “metameric effect” – the same colour appears differently depending on the angle, surface, and light source. Therefore, perception of colour can be subjective, which is why if you have stained teeth, you should consult a dentist.
How Are Dental Stains Categorised?
Broadly there are two classifications of stained teeth, which are as follows:
Extrinsic stains result from the absorption of chromogens into the enamel of the teeth as they regularly and frequently come into contact with them. It is on the outside of the surface of the tooth and most commonly results from:
- Tobacco smoking
- Staining foods and beverages
- Excessive exposure to certain minerals (iron, manganese, copper, silver)
Dentin, the layer underneath the enamel, absorbs the chromogens that cause intrinsic stains. However, these stains can also result from changes to the structure of the tooth. In general, dentin is yellower than enamel. It is also more porous and easily absorbs chemical dyes when exposed. Most commonly, intrinsic stains result from the following:
- Hereditary illnesses
What Causes Stained Teeth?
The following are the details of the most common causes of stained teeth. Keep in mind that the colour of staining can vary depending on the root cause of the problem.
Poor Oral Hygiene
If you don’t brush or floss your teeth, plaque will form around the teeth. It has a yellow or brown colour. After 48 hours, the plaque can harden into what’s known as tartar or calculus, which has an even darker shade.
Depending on the type of foods you’re consuming, your plaque might also have an orange colour. Plaque also causes erosion of the enamel, which can lead to the exposure of the dentin, exacerbating the staining.
Tobacco consumption can also result in the yellowing or browning of the teeth. According to a study published in the European Journal of Dentistry, smokers are also more likely to develop dental cavities, which can also change the colour of the teeth. Cavities can have different colours. They can appear as black, dark brown or as white spots.
The kind of foods you eat and the frequency at which you eat them can also impact the colour of your teeth. Some foods can also cause more staining than others. All of the following foods and beverages can cause tooth discolouration:
- Red wine
- Balsamic vinegar
- Soy sauce
- Tomato paste
Some of these foods are also acidic and decrease the production of saliva in the mouth. These two things can further contribute to the problem of staining.
Many illnesses affect the normal development of the internal and external structure of the teeth. It may be a result of the following:
- Metabolic disorders (alkaptonuria, erythropoietic porphyria)
- Chronic liver disease (green stain)
- Nutritional deficiencies (calcium, vitamin D)
- Autoimmune conditions (celiac)
- Dental anomalies (amelogenesis imperfecta, dentinogenesis imperfecta)
- Certain infections during pregnancy (affect the teeth of babies)
Medications & Treatments
Medications and treatments for different illnesses can directly impact the enamel of the tooth and the underlying dentin. For instance, you can end up with stained teeth as a result of long-term tetracycline therapy. It can affect foetuses during their second trimester and children as young as age eight. Even some adults experience discolouration from this. Tetracycline tooth discolouration can also be permanent.
Some other antibiotics, antihistamines (given for allergies), neuroleptics (for managing psychosis) and blood pressure medications can also cause this problem. The antiseptic mouthwash, chlorhexidine, is also known to cause tooth discolouration, although the stains are not permanent. Cancer treatments like radiation and chemotherapy can also result in the browning of the teeth.
There’s such a thing as too much fluoride as that can result in a condition known as fluorosis. When you’re consuming too much fluoride through different sources such as toothpaste, oral rinse, and supplements, you can end up with white spots on your teeth. Fortunately, this condition is reversible.
If you’ve experienced severe trauma or injury to your mouth, it can affect the nerves inside the tooth pulp (centre of the tooth, below the dentin). If the pulp is damaged and the nerves are dying, your teeth will change colour, appearing dark yellow, brown or black.
Tooth discolouration can result from amalgam fillings which can corrode and produce sulfides, staining the colour black. Another cause of stained teeth is an orthodontic treatment performed by an inexperienced dentist. When the forces on the teeth are too strong, the blood supply can be cut off, resulting in tooth death.
How To Prevent Stained Teeth?
Preventing teeth stains will depend on the kind of stains you have in the first place. Some kinds of intrinsic stains cannot be avoided, but you can do the following to prevent extrinsic stains:
- Reduce the consumption of staining foods and eat more crunchy foods as they scrub the teeth and produce more saliva.
- Try using a straw when drinking a staining beverage.
- Quit smoking.
- Rinse your mouth with water after each meal.
- Chew gum after meals as it can stimulate the production of saliva and wipe off the tooth surface.
- Maintain good oral hygiene.
- Get regular dental cleanings.
- Wear a mask in an industrial setting.
How To Get Rid of Stained Teeth
Your dentist may recommend the following treatments depending on the kind of stains you have.
Scaling & Polish
If the teeth are stained as a result of plaque formation, you might need scale and polish treatment. Although if the inflammation has spread deep into the gum pockets, you might also need a root planing procedure, which essentially smooths out the roots of the tooth.
Professional in-office teeth whitening is one of the most effective ways to get rid of extrinsic and even some intrinsic stains. Following the coat of a protective gel on the gums, the dentist applies hydrogen peroxide acid and shines a laser light on it. The results are immediate.
Many people try teeth whitening at home using gels, pens, trays and even using DIY pastes made of baking soda and charcoal. While these may work in some cases, they are likely not to work if the problem is moderate to severe. There are also health risks. The acid in certain teeth whitening products can end up irritating and damaging the gums. It will also take longer for you to see results if any.
If you have minor discolouration, for instance, as a result of craze lines, you can consider composite bonding. The dentist will match the shade of the bonding material with the tooth to hide the staining.
If the problem’s more pervasive and a significant surface area of the tooth is discoloured, you might benefit more from veneers. These are thin laminates which are bonded to the teeth using dental cement. It will also hide the underlying stains.
If the tooth is badly decayed or damaged, a dental crown might be recommended. For this, the dentist will first shave the existing tooth to create space for the dental cap. Keep in mind that a crown covers the entire tooth, unlike veneers.
You should know that our enamel also becomes thinner as a result of ageing, and the dentin becomes darker. So, naturally, teeth become yellower with time. However, it can be exacerbated by illnesses, treatments, dietary habits, trauma and oral habits. The kind of treatment you’ll receive will depend on the type of stain. Extrinsic stains are relatively easier to get rid of with different dental restorations, but keep in mind that it’s not possible to whiten, so you’d have to practice excellent oral hygiene.
Also, if the stained teeth are a result of medications, you should not stop taking medicine or switch it with another without consulting your doctor. If your teeth have changed colour, it could be due to different reasons. That is why you should always consult a dentist before deciding on a treatment.