Stannous fluoride can stain our teeth because the stannous (tin complex) which is bound to the fluoride can interact with sulfurs which results in staining. However, with recent advances in technology, the newer toothpaste formulations have drastically reduced its staining potential. Nonetheless, the potential staining is still on all toothpaste labels.
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History of stannous fluoride
In the early 1940s, Procter & Gamble started research into developing an anti-cavity toothpaste. The team was led by dentist and biochemist Joseph Muhler and inorganic chemist William Nebergall.
They succeeded in creating a toothpaste with stannous fluoride and consequently applied for a patent (US2876166A) in 1953. The patent met its natural expiration date in 1976 and is now freely usable across the globe.
The toothpaste was named Crest and became the first fluoride toothpaste to gain the ADA seal of acceptance. Prior to this the American Dental Association was against the use of fluoride in toothpastes.
Examples of stannous fluoride toothpastes:
Crest pro health bacteria shield and gum
Colgate total mint gum health
Sensodyne sensitivity and gums
Evidence of stannous fluoride staining your teeth
One of the earliest reports of stannous fluoride staining your teeth was from a 1982 study.
Researchers noted that a yellow-golden type of extrinsic stain formed on the tooth surfaces of experimental rabbits.
The low pH of stannous fluoride denatured the pellicle protein when exposed to sulfhydryl groups.
This led to the formation of stannic sulfides via reactions with the stannous ions.
In case you were wondering why there would be sulfur in our mouths, they're the byproduct of oral bacteria. Volatile sulfur compounds (VLCs) are actually one of the primary sources for bad breath.
In summary, stannous fluoride does not cause direct teeth staining. Although it can adversely interact with the sulfur in our mouths to form stains on our teeth.
Stannous fluoride (SnF2) is actually composed of tin (Sn) and fluoride (F). The metallic tin interacts with sulfur and that is how we get our stains.
Sodium fluoride (NaF) does not contain tin so it does not cause stains.
Sn is required to interact with the sulfur to produce teeth staining.
Stannous fluoride in the FDA database
Further evidence can be found in the FDA database in regards to the uses and effects of stannous fluoride. It is recognized as an anti-cavity agent which is good news. The bad news is that it can produce stains.
For all stannous fluoride treatment rinse, preventive treatment gel, and dentifrice products. "This product may produce surface staining of the teeth. Adequate toothbrushing may prevent these stains which are not harmful or permanent and may be removed by your dentist."
Unfortunately, the potential to stain teeth is a legitimate concern at least according to the FDA. Basically what we're trying to tell you is that, it is not a baseless statement. As further support, Dailymed NIH includes the staining warning on all stannous fluoride toothpastes. With this it should be clear to you about its potential staining capabilities.
products containing stannous fluoride may produce surface staining of the teeth. Adequate toothbrushing may prevent these stains which are not harmful or permanent and may be removed by your dentist.
Is stannous fluoride staining still a valid concern?
Staining from stannous fluoride is still a concern since it is impossible to eliminate it from occurring. However in recent years, toothpaste manufacturers have found ways to reduce the amount of staining caused by stannous fluoride.
According to Tufts, the initial formulation of SnF2 had a metallic taste and gritty feel. They also stained your teeth so dentists usually only used it as a last resort for patients who were at high risk for cavities.
However around 2004, Procter & Gamble patented a proprietary way to formulate a stannous fluoride toothpaste that is more palatable and less staining. Parodontax also made similar claims in that they found a way to make it less staining in 2006. Apparently the new formulation also tastes better as well.
Last but not least, a study in the Journal of the American Dental Association (JADA) verified that the new formulation does reduce stains. The study was titled, "Solving the problem with stannous fluoride".
The new Colgate Total stannous fluoride formulation had reduced stains.
This was compared to older versions of stannous fluoride toothpastes.
Our Critique
However, what we want to point out is that the study states that stains were reduced. This means that it now causes less staining than what it did previously. If they managed to completely eliminate it, they would've said "eliminated" instead of "reduced".
Due to that reason alone, we would say that stannous fluoride staining your teeth is still a possibility. We believe that the reduction in staining is most likely due to the advancement in abrasives within the toothpastes. They help by mechanically abrading stains off the exterior of your tooth and that is essentially how most whitening toothpastes work.
What the toothpaste label says
Toothpaste is toothpaste... but have you read the entire label for some of the stannous fluoride containing toothpastes such as the crest gum detoxify? There is a cautionary warning about teeth staining on it.
The video above shows you with concrete evidence that staining is still a possibility even with their new formulation. We do believe them when they say that they've significantly reduced the amount of staining but the fact that the warning is still present on the label implies that they haven't eliminated it completely.
We presume that long term use of it will probably very mildly stain your teeth but it'll get removed during the dental cleaning. If it was a very noticeable difference, the public would've been complaining about the product but since that has yet to be seen... we're going to say it is probably incredibly mild.
The Verdict - Does stannous fluoride stain teeth?
Stannous fluoride has been proven to effectively fight cavities but it can also potentially stain your teeth. Recent advances in technology have reduced the amount of staining from it but it is most likely still a valid concern.
The reason why we believe that is if you simply look at all of the toothpaste manufacturers and see what fluoride you use. The vast majority of the toothpastes use sodium fluoride while a subset uses stannous fluoride.
If SnF2 was as miraculous as they claim, we believe ALL toothpastes would've switched to it by now. Sodium fluoride would've been retired if that was the case. However reality shows that is not the case. Even the inventor of stannous fluoride toothpaste, Procter & Gamble (Crest) does not use it for all of their toothpastes.
Nonetheless, in our opinion it is still a great preventative product due to its cavity, plaque, sensitivity and gingivitis fighting potential. The only downside is the cosmetic outcome and it seems like the world made a decision via a popular vote to prioritize teeth whitening over fighting cavities.
You can check out our list of the best whitening toothpastes and you may notice that none of them use stannous fluoride.
