All whitening toothpastes will whiten your teeth by mechanically removing extrinsic stains and if they contain peroxide, it can even oxidize intrinsic stains as well. How potent your toothpaste is would depend on the formulation of its ingredients.
According to the American Dental Association (ADA), teeth become discolored and yellow due to the accumulation of extrinsic and intrinsic stains. Therefore in order to make them whiter and less yellow, you must reverse the process by removing all of the accumulated stains. That is essentially what teeth whitening is, possessing the ability to remove both types of staining.
Table of contents:
How to use whitening toothpaste effectively
Best way to use whitening toothpaste:
Floss. Stuck food will prevent toothpaste from contacting enamel.
Rinse. To remove food and wet your mouth.
Apply toothpaste to toothbrush.
Brush for 2 minutes. Brush every surface including the tongue side.
Wait 1 minute before spitting. This increases contact time of toothpaste with teeth.
Rinse thoroughly. So you don't swallow any toothpaste.
The most important thing about whitening products is that they work based on contact time. The longer that the toothpaste is in contact with your teeth, the more effective it'll be.
You can compare your brushing to an in-office whitening session at the dentist. The former is less than two minutes while the latter takes an entire hour. There is a significantly longer contact time when you whiten professionally with your dentist when compared to at home.
How whitening toothpaste removes extrinsic stains
Whitening toothpastes work by utilizing a mild abrasive to mechanically remove extrinsic stains.
In other words, it is a very physical process where surface stains get manually abraded away via brushing. Studies have shown that the abrasiveness of a toothpaste is the main determining factor in how effective it can whiten teeth.
According to a study in the Journal of Dentistry, the abrasive system is one of the key functional ingredients in whitening toothpaste.
The abrasiveness permits it to effectively remove extrinsic stains.
It also helps to prevent further ones from forming.
Despite the abrasiveness it is still gentle enough to not harm dental hard tissue.
Examples of toothpastes which only remove stains on the exterior of the enamel:
Colgate total whitening
Crest 3D white brilliance
Sensodyne extra whitening
Tom's anti-plaque and whitening
hello activated charcoal
Davids sensitive and whitening nano-hydroxyapatite
What are extrinsic stains?
Teeth can be discolored by extrinsic stains and as its name implies, they are located on the exterior of the tooth. These external stains develop a layer that covers over the outermost surface of the tooth enamel.
According to a study in the Compendium of Continuing Education in Dentistry, the extrinsic stains are mainly localized in the pellicle of the tooth. In other words the stains develop as a film or plaque that adheres to the exterior of the enamel.
They form as a reaction between sugars and amino acids.
May also be due to retention of chromophores in the film of plaque.
Basically an extrinsic stain is located on the exterior of the tooth while an intrinsic one is deeply embedded within the interior. That is the major difference between the two types of stains.
Causes of extrinsic stains:
Coffee
Tea
Red wine
Tobacco
Sodas
Curries and turmeric
Plaque and tartar
Anything that can stain your white t-shirt can stain your teeth. In other words, all pigmented beverages and foods have the capability to turn your teeth more yellow.
Meaning of mechanically removing stains
Whitening toothpastes can mechanically remove extrinsic stains when you brush it on teeth. It is the combination of the toothbrushing action along with the abrasives in the toothpaste that allows it to abrade away the stains. This is a mechanical process and not a chemical one because without the brushing motion none of the stains would get removed.
As evidence, look no further than a study about stain removal and whitening using baking soda by the Journal of the American Dental Association. The experiment used baking soda which is a mild abrasive to remove extrinsic stains but it did not possess the ability to chemically remove intrinsic ones. The results were astounding because baking soda was more effective in removing stains and whitening teeth than more abrasive toothpastes.
That just goes to show that teeth can be whitened by brushing them with a toothpaste that contains an abrasive system. Overall, studies have generally shown that brushing with it will whiten the teeth after a single day. However, it seems like there may not be further improvements in color after that time period.
Types of abrasives used by whitening toothpastes
Different brands of whitening toothpastes will use different types of abrasives to whiten teeth. Even within the same brand, different products may utilize a different one as well.
Below is a table showing various toothpastes and the abrasive that they use for whitening. The data was mainly from a study in Acta Odontologica Scandinavica. We added additional information such as common US brands of toothpastes to make it more relevant since we're based there.
Toothpaste | Whitening Abrasive | Relatin Dentin Abrasivity (RDA) |
|---|---|---|
Colgate Total | Hydrated silicon dioxide | 44 |
Oral B, Colgate whitening, Sensodyne | Hydrated silica | 65 |
Opalesence | Silica | 66 |
Tom's | Calcium carbonate, Sodium bicarbonate, hydrated silica | 49 |
Arm & Hammer | Sodium bicarbonate | 8 |
Hello activated charcoal | Activated charcoal | 90.67 |
Pepsodent | Silicon dioxide | 50 |
Clinomyn | Calcium carbonate, Silicon dioxide, Aluminium silicate | 124 |
Apoliva | Silica | 70 |
Acta Original | Natriummetafosfat | 45-60 |
Interestingly, some whitening toothpastes use multiple abrasives. The combination of abrasives can increase its efficacy. After all there are studies which test different abrasives to see if they whitened teeth such as this one on calcium carbonate.
Now you should have a full understanding of how whitening toothpastes whiten teeth. They do so by mechanically abrading extrinsic stains. This also implies that the fluoride in your whitening toothpaste has no effect on making your teeth whiter! It has everything to do with the abrasive system and not the fluoride.
In case you were interested, there is an entire chart of how abrasive toothpastes are:
How whitening toothpaste removes intrinsic stains
Whitening toothpaste can also whiten your teeth by chemically oxidizing deeply embedded intrinsic stains with hydrogen peroxide. A chemical oxidation agent is required because intrinsic stains are NOT surface stains so they cannot be removed mechanically.
According to a study in the Compendium of Continuing Education in Dentistry, in-office bleaching procedures utilize highly concentrated hydrogen peroxide to remove intrinsic stains. OTC products on the other hand used "low levels of hydrogen peroxide".
Therefore with the addition of peroxide to a whitening toothpaste, it gains the ability to oxidize intrinsic stains. In fact, a study by the Journal of Dentistry showed that between two toothpastes with peroxide, the one with a higher concentration whitened teeth more.
In other words if you want white teeth you should use a whitening toothpaste with the highest concentration of hydrogen peroxide that you can find.
Examples of toothpastes which can remove extrinsic AND intrinsic stains:
Colgate optic white pro series
Crest 3D white professional
Arm and Hammer advanced whitening
Supersmile professional whitening
The common ingredient among all of the toothpastes above is that they contain some form of peroxide. The concentration may vary among them but they at least have some of it in it. The best whitening toothpaste will of course have the highest concentration of peroxide.
What are intrinsic stains?
Intrinsic stains are different from extrinsic ones because they are not surface stains. As their name implies, these are stains that are below the surface of the tooth and located within the tooth structure. This makes them insulated from mechanical removal by brushing.
Possible causes of intrinsic stains according to the ADA:
Genetic disorders such as amelogenesis imperfecta
Localized factors such as fluorosis
Aging. Enamel becomes thinner and more translucent which permits the more yellow dentin to show through.
Tetracycline use
Tooth decay
Amalgam restorations
Dead teeth
Using chlorhexidine mouth rinse
Pigmented foods and beverages such as coffee, tea, and red wine.
How hydrogen peroxide oxidizes intrinsic stains
Since intrinsic stains are not on the exterior of the tooth, it makes whitening agents that work via mechanical removal of stains ineffective for it. The only way to get rid of them is by using a chemical agent to oxidize them.
Hydrogen peroxide is able to achieve this by diffusing through the tooth while oxidizing all of the organic matrices that contain intrinsic stains. It is so potent that it can diffuse all the way to the pulp within 15 minutes of application.
What is of interest is that the peroxide only oxidizes the organic component of your tooth while leaving the inorganic matrices intact. The significance of that is the enamel is composed of only 1-2% organic matrices while 98-99% inorganic. The dentin on the other hand has about 10x as much organic components than the enamel. This means that teeth whitening affects more than just the enamel because it also whitens the dentin.
The reason the enamel contains so much inorganic substances is because it is mostly made of hydroxyapatite. That is the primary mineral that gives teeth its hardness. Your bones also contain it as well but still not as much as your teeth. Yes, your enamel is the hardest substance in the human body.
Why whitening toothpaste may not work
People often look for alternative ways to whiten their teeth because they feel like they brush their teeth everyday but they're still yellow. They are not getting the cosmetic results that they're looking for. The reasons for the lack of result is not because the whitening toothpastes don't work but rather they want a much more dramatic result in a short period of time.
Unfortunately there are many factors which influence the whitening efficacy of toothpaste. Some of which are out of your control. Then there is also the fact that the concentration of whitening agents within the toothpaste is fairly low.
Factors which decrease the whitening efficacy of toothpastes
Whitening toothpastes have been proven to whiten teeth but there are quite a few factors which influence its efficacy. The first being the presence of saliva and the second is due to the fact that you only brush for two minutes. These all make it less effective and are probably the reason why you don't see drastic whitening results.
The effect of saliva on whitening
Saliva is the arch nemesis of teeth whitening because it naturally contains salivary peroxidases. These peroxidases are enzymes which break down all kinds of peroxides and that includes the hydrogen peroxide in your whitening toothpaste.
You may be wondering why your body is overflowing with salivary peroxidases but it's not because it is trying to prevent you from having whiter teeth. The bacteria in your mouth actually produce a lot of hydrogen peroxide. The enzymes in your saliva breaks them down to prevent you from getting oxygen toxicity.
In other words it is a protective mechanism to protect you from getting poisoned. Nonetheless, it is due to the presence of salivary peroxidases that you can swallow whitening gel and not die. This is also the reason why the toxicology department of the public health of England says it is safe to use hydrogen peroxide products. It gets rapidly detoxified by the peroxidases before it even reaches your blood.
Unfortunately what this means is that a lot of the peroxide that you are using will start to become deactivated once it comes into contact with saliva. As you know you start salivating a lot when you are brushing your teeth. This phenomenon significantly decreases the efficacy of the whitening toothpaste. Nonetheless, we do have an article with tips on how to stop saliva while bleaching.
Two minutes of whitening is insufficient
Another often forgotten factor is that brushing your teeth for two minutes or rather whitening your teeth for only two minutes is insufficient. That is an incredibly short amount of time to be whitening your teeth. It is simply not enough time for your teeth to get white.
You can compare this to an in-office whitening treatment which lasts a grand total of about one hour. You can also compare it to using the Crest 3D white strips which ask you to whiten for at least 30 minutes.
Basically all of these other whitening treatments require you to whiten your teeth for a much longer period of time. However the whitening toothpaste only requires you to brush with it for a mere two minutes. That is nowhere near enough time for your teeth to whiten which was basically the conclusion that this study came to as well.
Then you also add in the fact that you have saliva present along with a low concentration of hydrogen peroxide. That combination makes the toothpaste less effective than other products.
People are impatient
When it comes to teeth whitening, the vast majority of people tend to be impatient. They want white to see very white teeth and they want to see it fast.
That is an inherent problem for whitening toothpaste because even the most potent ones contain only 4-5% hydrogen peroxide at most. The concentration for the whitening agent will always be lower than a professional take home product or in-office session at the dentist. In fact, that concentration is lower than a lot of the other OTC whitening products such as the whitening strips or trays.
According to a study by the British Dental Journal, the concentration of hydrogen peroxide is irrelevant for the potential of how white teeth can get. Bleach is bleach so even 3% peroxide concentrations can whiten teeth to the same level as 35% ones.
Apparently the only difference is that the higher concentration gel will whiten your teeth faster. In other words a higher concentration product will require less treatment time. A lower concentration product will require you to whiten for a much longer period of time to achieve the same results.
Basically if you want instantly whiten teeth, you should aim to procure the most potent whitening product that you can. Unfortunately these are only available professionally through your dentist and not over the counter.
To summarize, if you are going to use whitening toothpaste as your primary means of getting whiter teeth you will need to be patient. You need to use it for a long period of time before you expect to see dramatic results.
How long does it take to whiten teeth with toothpaste?
Unfortunately there haven't been any long term studies on whitening toothpaste's whitening effects. Most studies did report an immediate improvement in tooth shade from using it after a single day. No studies bothered to test the amount of whitening after say six months of using the product.
Basically you can expect to see "whiter" teeth after brushing with it on the first day. However whether or not you get any further improvements after that is unknown. Therefore, how long it takes to whiten your teeth with toothpaste is still a bit of a mystery.
More effective whitening than toothpaste
There are two major weaknesses of whitening toothpastes which make them less effective than other bleaching products. They come in a low concentration of peroxide and they have no protection against saliva. Therefore other whitening methods which may be more effective should possess these two qualities or at least means to address them.
Overall we would have to say that just about every OTC and professional teeth whitening product that you can think of will most likely work better than it.
Here are some examples of what would be more effective:
Whitening strips
Whitening trays
Professional take home kits
In-office sessions at the dentist
All of these products listed above come in a higher concentration of hydrogen peroxide or a derivative of it. That immediately makes them more effective.
In addition to the potency, they also offer some type of protection against saliva.
The strips act as a barrier to prevent saliva from touching the gel.
The trays wrap around the teeth to try to hold the gel against your teeth.
The professional trays do the best job of protecting your teeth since they are contoured to the shape of your teeth.
The in-office session is the most effective because your dentist has a saliva ejector that suctions up all of the saliva while the bleaching gel is working.
Simply having some sort of protection against saliva, allows the peroxide to work more effectively because it can work longer before it becomes deactivated. Without any protection, the saliva is free to enzymatically degrade the peroxide.
Should you not use whitening toothpaste?
Despite there being more effective teeth whitening products it does not mean you shouldn't use it nor is it bad for you. You still need to brush your teeth to get rid of plaque and to fight cavities so you will always need a toothpaste. If your primary concern is having whiter teeth you should definitely choose a whitening toothpaste over a non-whitening one.
When we say whitening, we recommend using one with hydrogen peroxide because studies have shown that it does make a difference. In fact, the toothpaste with a higher concentration of peroxide will whiten teeth more effectively than the ones with a lower strength. One of the most potent peroxide toothpastes available is the colgate optic white.
It may not give you drastic results but it still fulfills its role. If you use it long term it can possibly decrease the amount of other OTC whitening products that you use. This means it can help you save money since it is the least expensive whitening option!
The Verdict - Does whitening toothpaste work?
Whitening toothpaste definitely does work in whitening your teeth because it can remove both types of stains which discolor your teeth. The extrinsic stains get mechanically removed by the abrasives while the intrinsic ones get chemically oxidized. Basically it utilizes both mechanisms for whitening your teeth.
Despite being an effective tooth whitener, it is not the most effective one if you want to see significant results. The presence of saliva, low concentration of hydrogen peroxide, and the short brushing time make for a less effective combination.
If you're looking for a faster and more drastic result, we recommend that you check out other types of whitening treatments. However that doesn't mean you shouldn't use whitening toothpaste because you still need to use one to prevent the further accumulation of stains. It should still be a part of everyone's whitening armamentarium to fight against yellow teeth.
