You Brush Everyday But Teeth Are Still Yellow

Written & Reviewed by Dr David Chen

Diligently brushing your teeth everyday is effective in removing extrinsic stains but not so much for intrinsic stains. So are your teeth yellow due to discoloration from external or internal stains? Depending on your answer, that could very well be the reason for why they’re still yellow despite all of that brushing.

colgate total toothpaste

Extrinsic vs Intrinsic stains

Not all teeth stains are the same because there is a distinct difference between extrinsic and intrinsic stains. According to NYU Scholars, teeth discoloration can either be intrinsic or extrinsic in nature. However, the overall discoloration of the tooth could be from a combination of both as well.

Intrinsic stains are those which affect the internal tissues of the tooth. They are deeply embedded below the surface layer of the enamel. They can even reach as far as the dentin layer of the tooth. In other words, they are enclosed within the internal structure of your tooth.

Human tooth diagram - KDS4444
Credit: KDS4444

Extrinsic stains only affect the outermost layer of the enamel. They are typically a result of a film, pigmentation, calculus, or food which may have adhered to the outer surface of the enamel. This stain is literally covering over the outer surface of your tooth.

Causes of yellow teeth

There are a variety of causes which may stain your teeth and turn them yellow. According to the Journal of Evidence Based Dental Practice, the stains are due to lifestyle habits, dietary habits, and possibly genetics. Together they make up the bulk of the intrinsic and extrinsic stains that you see.

  • Staining foods and drinks
  • Smoking
  • Poor oral hygiene
  • Natural aging process
  • Genetics
  • Medication
  • Dry mouth
  • Trauma
  • Amalgam restorations
  • Tooth decay

Food and drinks

Drinks such as coffee, tea, and red wine are notorious for staining your teeth. Those who consume a lot of it tend to expect to not have white teeth. Aside from drinks, a lot of foods can also cause intense staining such as curries with turmeric in it. That will stain shirts and ladles. Your teeth are no exception!


Heavy smokers who’ve been smoking for a long time usually don’t have the best teeth. Tobacco contains a lot of tar and according to the NHS, it is a sticky brown substance that will stain not only a smoker’s teeth but also their fingers. It will turn it into a yellow-brown color.

Inadequate oral hygiene

Plaque and tartar can acquire a lot of stains from the foods that you eat. If you don’t brush them off, the plaque and tartar can start changing colors. Those who smoke a lot can sometimes end up with a condition called black tartar.


Over time, an individual will start accumulating staining and yellowing of the teeth. That’s just a natural part of life because the vast majority of the foods that we eat do in fact have color in them. The coloring will slowly leech into our enamel over a long period of time.


Those who are less fortunate may be born with thinner enamels. What that means is the dentin layer underneath which is more yellow may show through. This will cause your teeth to look more yellow. Those who have thicker enamel will be more blessed with being able to keep their teeth white more easily.


There are certain medications which can cause terrible staining on your teeth such as tetracycline. That was a very popular medication that was used to control acne but an unintended side effect was making causing intense stains on your teeth. These stains also happen to be intrinsic in nature and not extrinsic, which makes them even harder to remove!

Dry mouth

Individuals who take a lot of medication may end up with a dry mouth. That is a common side effect for a lot of medications. When your mouth dries up, you produce a lot less saliva, which means it will be easier for plaque to form on your teeth. That can certainly make your teeth look more yellow if you have a lot of plaque covering the surfaces of the enamel.


Teeth that have been injured or have sustained trauma can potentially die. A dead tooth will slowly start yellowing or even turn grey when given sufficient time. These teeth should be whitened externally as well as internally in order to change their color.

Amalgam restorations

Amalgam (silver) fillings tend to stain the natural tooth. The black color will slowly leech out over time and cause the surrounding tooth structure to turn black like the amalgam. That doesn’t make it a cavity but it is a cosmetic concern for patients.

Tooth decay

Cavities present in a spectrum of a brown to black color. Untreated tooth decay can cause your teeth to appear less white.

Brushing excels at removing extrinsic stains

Due to the public’s general sentiment of dissatisfaction with tooth color and desire for whiter teeth, toothpaste manufacturer have incorporating “whitening” to their products. According to the Journal of Dentistry, one of the key properties of what makes a whitening toothpaste is it’s abrasiveness.

It is the abrasive property of the toothpaste which gives it the ability to remove extrinsic stains. These stains are removed mechanically via directly scrubbing or brushing the surfaces of the teeth. It is akin to scrubbing a table top and that is what we mean by mechanical removal.

These are all surface or extrinsic stains since they reside on the outermost surface of your tooth. Since you can only brush the outer surface of your teeth, these are the only type of stains that it can remove.

Is a more abrasive toothpaste more effective at extrinsic stain removal?

Contrary to what you may think, a more abrasive toothpaste may not necessarily be more effective at stain removal. According to the Journal of the American Dental Association, dentifrices that contain baking soda is actually very effective at extrinsic stain removal. In fact, it is more effective than a vast majority of its more abrasive competitors which don’t contain baking soda.

Baking soda happens to be very mildly abrasive and is one of the safest toothpastes that you can use. The only toothpaste that is less abrasive than it would be plain water. Everything else on the market is much more aggressive and abrasive than it on your enamel.

Toothpaste RDA chart

That is basically how baking soda whitens your teeth, by mechanically removing extrinsic stains. There are various ways to use it such as making your own solution or you can simply purchase a brand that already uses it such as Arm & Hammer. In fact, that is how all whitening toothpastes work, they whiten via mechanical removal of external stains.

Limitations at removing extrinsic stains

Brushing with a whitening toothpaste may remove and prevent extrinsic stains from yellowing your teeth but there are limitations. If you happen to have a lapse in your oral hygiene routine and forget to brush some nights, you can get tartar (calculus) formation on your teeth.

Prior to tartar developing, it starts off as plaque which is very soft. Plaque you can brush off with gentle motions but if you don’t remove it before going to bed, it will harden into a calcified substance called tartar.

Once the tartar forms you will no longer be able to brush it off despite the abrasive property of a whitening toothpaste. The only way to remove hard tartar is by getting your teeth cleaned professionally by a dentist or hygienist.

When we say it is the only way, we mean it. You can brushing as hard as you want on the tartar but it will never come off and we can guarantee you that. Yes, studies have shown that brushing with a whitening toothpaste is effective at removing extrinsic stains but they do have limitations.

Brushing does not remove intrinsic stains effectively

Despite brushing your teeth everyday with whitening toothpaste your teeth may still be yellow if most of the staining is of intrinsic origins rather than extrinsic. The brushing will mechanically remove the extrinsic ones but it will have little effect on the intrinsic ones.

You can only brush the outermost surface of the teeth because you can’t brush the inside of a tooth. That is physically impossible. According to the Journal of American Dental Association, the second major way to remove stains is via a chemical mechanism by bleaching the tooth with peroxide.

Since most whitening toothpastes only have an abrasive property and nothing else, they don’t usually contain any peroxides. In other words, most of them lack the ability to remove intrinsic stains. That makes them effective for extrinsic stain removal but not intrinsic.

Therefore, if your yellow teeth are due to intrinsic stains, your whitening toothpaste may not do much to change it’s color. You can brush multiple times a day for an entire year but you’ll most likely see very little results.

Exception – toothpastes which do contain peroxide

There are exceptions to the rule because manufacturers have taken notice that patients do want a more effective whitening toothpaste. Due to this, some of them have started incorporating their products with hydrogen peroxide. Yes, you read that right they added peroxide to their toothpaste so that it can have an intrinsic stain removal characteristic.

arm and hammer advanced white toothpaste

Some examples of toothpastes which contain peroxide:

If you use a whitening toothpaste that contains peroxide, you will be able to remove both extrinsic AND intrinsic stains. These are definitely much more effective at whitening your teeth than those without any peroxide.

If your teeth are still yellow despite diligent brushing, you may want to chose a toothpaste that has an intrinsic stain removal property. In other words, look for a product that contains peroxide because all of the best whitening toothpastes have it.

How does hydrogen peroxide remove intrinsic stains?

The intrinsic stain removal process works via a chemical mechanism which is different from the extrinsic process. The only substance that can whiten teeth chemically is hydrogen peroxide or one of its derivatives.

Peroxide diffuses through the tooth and oxidizes all of the organic structures that it encounters. Basically all of the intrinsic stains are embedded within the organic matrices of the tooth.

It is so potent that it can even diffuse its way to the pulp. Yes, it means that it passes through the enamel and dentin. Studies have shown that peroxide were present in the pulp of the tooth after whitening for 15 minutes.

Due to this reason the whitening ingredients in toothpaste are very important. You have to make sure that it has peroxide if you really want them to whiten.

How to get rid of yellow teeth if brushing doesn’t work

If you’re already using whitening toothpaste that has peroxide in it but it isn’t making your teeth less yellow, you may need to try a different whitening method. These other methods can be divided into OTC products and professional ones.

Original SNOW teeth whitening kit

Other the counter whitening products:

  • Teeth whitening pen
  • Whitening strips with or without LED light
  • Whitening trays with or without LED light

Professional products:

  • Customized take home kits
  • In-office treatment
Kor Whitening take home kit

The advantage of these whitening products over brushing your teeth is that they typically come in a higher concentration and offer some type of protection against saliva.

Higher concentration whitening gel

The whitening toothpastes which do have peroxide in them usually have a fairly low concentration of it. It is often so low that it doesn’t even list the percentage. The most potent toothpaste would be the Colgate optic white where it comes in a 5% hydrogen peroxide solution.

The more potent whitening products usually contain a much higher concentration of peroxide than the toothpastes. The most obvious example would be the in-office treatment at the dentist which can go up to around 35% which is far higher than what you can buy OTC.

With that being said, the concentration of peroxide doesn’t affect the ceiling limit of how white your teeth can get. According to a study in Nature, all concentrations can potentially whiten your teeth to the same level, it is just that a more potent one requires less treatment time.

  • More potent will whiten faster and require less treatment time.
  • Less potent will whiten slower and require more treatment time.

If you feel like your product with hydrogen peroxide isn’t whitening your teeth, you may be using a low concentration product and you’re not giving it enough time. If you want to see immediate results, you should use a stronger one instead.

Protects against saliva

An often neglected variable in what affects the efficacy of whitening gels is the ability of your product to prevent saliva contact with your teeth. Your saliva contains a lot of enzymes that can break down the whitening gel. It is able to do this because your body naturally has salivary peroxidases which serves as a defensive mechanism against hydrogen peroxide.

That whitening toothpaste will not be as effective compared to something like a whitening strip or whitening trays because it does not protect the gel from saliva. The strips and trays do act as a barrier which prevents saliva from coming into contact with your teeth.

Kor whitening placing whitening gel
in-office whitening saliva isolation

Reduced saliva contact will allow the peroxide to work for a longer period of time, thus maximizing the treatment time. If you’ve ever had in-office teeth whitening done your dentist has your mouth isolated with cotton rolls and the saliva ejector which suctions up all of the saliva. This is all to prevent the gel from getting broken down by salivary enzymes!

What we’re trying to say is you may want to try a different product which offers some sort of saliva protection. That’ll probably get your teeth whiter since it’ll permit the peroxide to work more effectively.

How to prevent teeth from yellowing

One of the most effective ways to have whiter teeth is to actually prevent them from getting yellow in the first place. If they don’t get yellow, you wouldn’t even need to worry about whitening them. As the saying goes, an ounce of prevention is worth a pound of cure.

How to keep your teeth white:

  • Avoid staining foods. Try your best to minimize the consumption of staining foods or drinks such as coffee, tea, and red wine. Drinking through a straw will help because it prevents the liquid from coming into contact with your enamel.
  • Brush twice a day. Make sure you brush for two minutes at least twice a day. This will get off all of the stains and prevent it from hardening into tartar. It’ll decrease the chances of the stains getting deeply embedded into the tooth structure.
  • Periodically whiten your teeth. Even after undergoing whitening you should still do maintenance sessions at least once a month. This helps to preserve the whiteness of the teeth and prevent it from relapsing.
  • Dental cleaning. You may try your best to keep plaque and tartar away but it still forms sometimes. If it does you will require the help of your dentist to remove these stains.

Is yellow teeth unhealthy?

You may think that yellow teeth are purely cosmetic in nature and while that may be true for most cases, there is one exception to the rule.

If your yellow teeth are due to heavy tartar build up that has been stained yellow then your yellow teeth are unhealthy. The reason is because the cause of your discoloration is due to periodontal disease.

However if your yellow teeth are simply from extrinsic and intrinsic stains then it is probably healthy. Since staining is purely cosmetic in nature, it does not affect the function, integrity, nor health of your teeth.


Brushing your teeth is very effective at removing extrinsic stains and it can help to whiten them. However if your yellow teeth is more than surface deep and you have intrinsic stains, you may need the help of a whitening agent such as hydrogen peroxide.

The reason is because brushing will only mechanically remove surface stains but will do little to remove intrinsic ones. It is literally impossible to brush the inside of your tooth right?

The most likely reason for your teeth to still be yellow even brushing everyday with a whitening toothpaste is that you have intrinsic stains. You should give one of the OTC whitening products a try to see if it can whiten them. If that still doesn’t work, you can always have them professionally whitened. Although that does tend to cost more.


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