What exactly is in my toothpaste?

Perhaps the most popular personal hygiene product in history is toothpaste, or at least some version of it.  Throughout the centuries different substances and combinations have been used, some based on science, some based on personal beliefs, and others based on superstition or just plain quackery.  Modern toothpaste is the result of years of scientific research and measured studies, but is still not without its critics and controversies.  The most common toothpaste brands and formulations all have the same basic types of ingredients, and in this post I attempt to break things down to provide a better analysis of exactly what we’re putting in our mouth every morning and night.

When looking at the ingredient list on a tube of tooth paste you’ll notice one or two active ingredients and a long list of inactive ingredients.  What you won’t see is a nutrition label as is present on all foods.  That’s because the FDA doesn’t consider toothpaste a food, in fact it is in the unusual category of a cosmetic and a drug.  The reason for this is that toothpaste is not meant to be ingested (granted that some will accidentally be swallowed or absorbed through the oral tissues during use).  Fluoride is very helpful in small doses but not so much in large doses, so it is important to emphasize spitting and rinsing afterwards, especially for kids.

The active ingredients are obviously doing the main job of keeping your mouth clean and healthy, but the inactive ingredients are there for a reason too.  It’s kind of like a chocolate chip cookie: the chocolate chips are the main attraction, but the rest of the cookie has its charms.  Anyhow, I’ll also cover the most common inactive ingredients and why they’re in there.

There’s a common misconception about how much toothpaste is really necessary to get the job done.  The advertisers would have you believe you need to squeeze out something that looks like a giant caterpillar.  Here’s the reality: the most you need is a dab no bigger than the size of a pea.  Emphasis on the no bigger than; kids need even less.  I heard a statistic a while ago that 97% of Visine ends up running down the side of your face.  Don’t commit the same crime with your toothpaste; if you see blobs of it in your sink when you’re done brushing, you’re using too much.

I’d like to make an important point at this … uh … point: when it comes to choosing the right toothpaste, you are not alone!  Your dental team is there to help find the best product based on your particular set of needs.  We even have access to products that can’t be purchased over the counter.  Also, if you are having issues such as tooth sensitivity, don’t rely on a toothpaste to mask the symptoms.  If your teeth are sensitive, there’s a reason.  Don’t be the person trying to fix the hole in their tooth with Sensodyne.

A final word before we get started: just about anything that is currently in toothpaste, or ever was in toothpaste, has come under attack from time to time as being useless to harmful to deathly toxic by one group or another (with the possible exception of water, but that’s probably just a matter of time).  I’m not an alarmist, but I will identify any potential controversies as we go through the list and try to provide some perspective.

So without any further ado, I present to you the:

Active Ingredients

Fluorides

I think it’s pretty well known that the main purpose of toothpaste is to give your teeth a good coating of fluoride when you brush.  When it comes to fluoride in toothpaste, the most common form is Sodium Fluoride, or NaF.  It’s effective, cheap, and doesn’t mess with the taste.  Some brands use fluoride in a different form, Stannous Fluoride, or SnF.  Stannous is the chemical name for tin.  Stannous fluoride is actually more effective at delivering the cavity-fighting effects of fluoride to the teeth and it also has been shown to help with sensitivity, but it’s more expensive, can produce mild staining, and can alter the taste.  For people who need a little extra help in keeping cavities in check or sensitivity control, finding a brand with SnF as opposed to NaF may be worth it.  Another less common form of fluoride is Monofluorophosphate, or MFP, and studies show it is equal to NaF in fighting cavities.

Antibacterial

Some brands include another active ingredient called Triclosan.  Triclosan helps control bleeding gums (gingivitis) by killing the bacteria that causes it.  Although effective in this role, there is some controversy as to its use in toothpaste.  The FDA has banned triclosan for use in hand wash products for two reasons: lack of proven efficacy and potential adverse health effects.  It is still allowed in toothpaste, and it is proven to help control gingivitis, but its effect on the rest your body is disputed.  Bottom line, if you don’t have a major issue with bleeding gums you may not notice any real benefit and it may be smart to stick to products without it.  Often included with triclosan is PVM/MA copolymer which simply helps it work better.

Zinc citrate is included in some brands to help control the bacteria that causes bad breath.  This is the same zinc citrate that is included in multivitamins.  Some brands use it alone or in combination with triclosan.  Studies show it works quite well.

Desensitizers

Just about all brands have a line of “sensitivity” toothpastes, with the most common desensitizer being Potassium Nitrate, or KNO3.  Potassium nitrate is useful ingredient in many products, including fertilizer, gunpowder, rocket propellant, and, of course, toothpaste.  It turns out the potassium part does the real work in reducing sensitivity and the nitrate part is just along for the ride.  That’s why you might see other potassium-containing agents such as potassium chloride (KCl) or potassium citrate used instead.  Science is still trying to figure out exactly how potassium works as a desensitizer and it turns out to be effective for some but not all.  Numerous other compounds are used to control sensitivity, usually in the form of something blocking access to the nerve by “clogging up” microscopic channels in the tooth structure, again with moderate and varied success.  In my experience, sensitivity products do work for most people, the key is to find a product or combination thereof that works the best for you.

Inactive Ingredients

Abrasives

Yes, there are abrasives in toothpaste, and yes, they can constitute up to 50% of the volume.  The abrasives help clean the teeth and allow the fluoride to do its job better, but typically are mild enough not to damage the teeth.  The most common abrasive is hydrated silica (or other silicas), followed by the carbonates – Sodium bicarbonate (NaHCO3 or baking soda), calcium carbonate (CaCO3) and magnesium carbonate (MgCO3), alumina and several phosphate complexes.  I’m not going to go into the specifics of each, but I will make some useful generalizations.

The enamel on your teeth is the hardest substance in the body.  Using the Mohs Scale of hardness (from 1 to 10, where 1 is talc and 10 is diamond), tooth enamel ranks a 5, about the same as glass.  Tooth enamel can generally hold up very well to any of the abrasives listed above during normal brushing.  However, the inner part of your teeth, called dentin, is much softer.  Dentin ranks a 2.5 on the Mohs Scale, and based on how the scale works, it means that dentin is about five and a half times softer than enamel.  If dentin gets exposed anywhere in the mouth it is susceptible to wear.  The most common path of exposure is gum recession; the exposed root surface is unprotected dentin and is very vulnerable to wearing away at an accelerated rate.

If you don’t have any gum recession in your mouth, or any areas where the enamel is worn away, abrasives shouldn’t be a concern for you.  For the rest of us, here’s what to look for.  The mildest abrasive on the list is sodium bicarbonate, or baking soda.  It still cleans your teeth effectively and will go gentle on your precious dentin.  Regular toothpastes without any “enhancements” (whitening, tartar control) will have relatively mild abrasives.  Whitening toothpastes will have medium-to-strong abrasives.  Why?  Basically what whitening toothpastes do is remove surface stains from the teeth, and in doing so, the teeth look whiter and shinier without any actual “whitening” taking place.  I’ll discuss whitening more later.  Toothpastes with the strongest abrasives are typically the tartar control varieties.  Tartar, also known as calculus, is the hard stuff that builds up on your teeth and needs to be removed by your hygienist.  Strong abrasives will help wear it down and limit its buildup, but they will also wear down anything that gets in their path, including exposed dentin.

A final note on abrasives:  One very easy way to limit the amount abrasives getting on your teeth is to use a very small amount of toothpaste.  Remember – pea, not caterpillar.

Surfactants/Detergents

These are ingredients to help the toothpaste “foam up” and spread out evenly over the teeth.  The same ingredients are often found in shampoo and some soaps.  The most common, and the most problematic, is Sodium Lauryl Sulfate, or SLS.  For people who tend to get mouth ulcers (aka canker sores) frequently, SLS may be the culprit.  Most manufacturers offer a line without any SLS for this reason.  Another less-common detergent is Cocamidopropyl Betaine which is derived from coconut oil.  I’ve never heard anybody say it causes mouth sores, probably because nobody knows how to pronounce it.

Humectants

A humectant is a substance that helps preserve moisture.  They are added to keep your toothpaste smooth and creamy (good) instead of dry and crumbly (bad).  Glycerin and sorbitol, both common food additives, are the most used.  Some of the abrasives, such as hydrated silica, also contribute to water retention.

Also often used is propylene glycol, a cousin of ethylene glycol which also known as antifreeze.  Propylene glycol is actually used in a similar fashion to de-ice aircraft wings or as an antifreeze in environmentally-sensitive applications such as boat engines.  Before you get too excited and try to sue Procter & Gamble for poisoning your mouth, you should know that you’ve likely been consuming propylene glycol in other products all your life.  The FDA has labeled it “generally recognized as safe” (GRAS) and it is used as an additive in ice cream and other frozen desserts, and in the pharmaceutical industry in making drugs such as Valium and Ativan and certain formulations of artificial tears.

The only real concern with propylene glycol is that some people develop an allergic reaction to it in the form of inflammation or redness, called a contact dermatitis.

Polyethylene glycol, another non-toxic version of ethylene glycol and often abbreviated as PEG-8 or PEG-12, is sometimes used as well.  PEG is normally used in medicine as a laxative.

Thickeners

Thickeners serve a similar role as humectants in determining the texture and viscosity of your toothpaste.  The most common ones are types of cellulose, which is the basic building block of all plants (think: wood).  Carrageenan (made from edible seaweed), carboxymethyl cellulose (CMC, also known as cellulose gum), and xanthan gum (made from the fermentation of sugars) are the most common.  Xanthan gum therefore may be derived from products to which some people may be allergic, such as corn, soy or wheat.  Other “gum” thickeners include guar gum and locust bean gum.

Sweeteners

Many of the above-mentioned ingredients in toothpaste provide some sweetening ability along with their main roles, such as sorbitol and glycerin.  Saccharin used to be commonly used in food as an artificial sweetener before suffering some bad PR and is now largely replaced by aspartame.  Still, it is considered very safe in small doses and is a common sweetener in toothpaste, especially since it’s not meant to be ingested.  A less common one is Potassium Acesulfame.

By far the best sweetener is Xylitol (pronounced zy-li-tol).  Xylitol is a natural sweetener derived from common plant sources.  Unlike artificial sweeteners, which have no calories, xylitol actually has 2.43 calories per gram (sugar has 3.87) but is considered safe for diabetics because its effect on blood sugar is minimal.  The best part of xylitol is that the bacteria in your mouth can’t process it, and it actually inhibits the growth of certain bacteria, providing a one-two punch in the battle against tooth decay.  The reason you don’t see it much in toothpaste is because it’s fairly expensive, but if you can find it it is an excellent choice.

One word of caution: xylitol can be fatal to dogs.  Come to mention it, fluoride is harmful to dogs too.  If you have a dog that will actually let you brush his teeth, they make toothpaste specifically for pets which can be found at most pet stores, in exciting flavors like poultry and bacon.

Whitening agents

As mentioned above, the primary method by which whitening toothpaste makes your teeth appear whiter is removing surface stains.  It accomplishes this through abrasives and other ingredients meant to dissolve common stains from foods and beverages.

The main ingredient in any true whitening product, or “bleaching” product, is hydrogen peroxide (or its more stable cousin, carbamide peroxide).  Toothpaste contains no peroxide (at least the ones I’ve seen) and therefore doesn’t do any true “whitening” of the teeth.

Tartar control agents

Names of tartar control agents take the form of __Sodium __Phosphate, such as pentasodium triphosphate or tetrasodium pyrophosphate.  Sometimes Calcium Phosphate is used instead.  Basically they act like the rock salt in your water softener.  Here’s how it works:  Your saliva contains a lot of minerals like Magnesium (Mg) and Calcium (Ca) that like to build up on your teeth, forming tartar (or calculus as it’s known in some circles).  Tartar makes a perfect home for bacteria, allowing them to set up shop and wreak havoc in your mouth.  Controlling tartar = controlling bacteria.  The __sodium __phosphate will interact with these minerals and prevent them from building up on your teeth, just like your water softener interacts with the minerals in your water and washes them down the drain, making your water “soft.”  Thus you could say that tartar control toothpaste is like “saliva softener.”  It works pretty well, too, if you can get past the taste.

Here’s the rub.  The minerals in your saliva, specifically calcium, play a role in “repairing” teeth in areas where a cavity is getting started.  The decay process starts when acid removes minerals from your tooth enamel, and the calcium in your saliva can bond back on and “heal” the spot.  However, if you’re using tartar control toothpaste, you’re removing calcium from your saliva and limiting your ability to heal those areas.  My recommendation: for patients who are more cavity-prone I usually try to steer them away from tartar control toothpaste.  For the rest of us it’s fine and probably helpful.

Polyethylene

Polyethylene is a fancy name for plastic.  Some manufacturers used to put tiny, colorful plastic beads in the toothpaste to enhance its appearance.  I’m not sure any of them do anymore.  You probably have the following questions:  Q: Do I need plastic beads in my toothpaste?  A: No, they serve absolutely no purpose.  Q: Then why are they in there?  A: To make your toothpaste look pretty.  Q: Does my toothpaste need to look pretty?  A: No, unless you’re using it to decorate a cake.  Q: So I can use toothpaste to decorate a cake?  A: No, toothpaste is not a food (see above).

Coloring Agents

The most common coloring additive is Titanium Dioxide (TiO2).  Although listed as Generally Recognized as Safe (GRAS) by the FDA there has been some controversy as to it possibly being a carcinogen (cancer-causing).  Titanium Dioxide starts off as a white powder and performs two main roles in the food and healthcare industry.  For food products it makes things white and opaque (non- see through) and is often used in frosting, powdered sugar and other candies and sweets.  It turns out that titanium dioxide also reflects the sun’s UV rays quite well so it is included in skin creams and sunscreen.    However we don’t want to be walking around with white, opaque lotion on our skin (I’m just making an assumption here) so they grind the powder into very, very small particles, called nanoparticles.  In this nanoparticle form the titanium dioxide still blocks UV rays but is now transparent (invisible) on the skin.

The nanoparticle form is also the potential cancer-causing form, but only when it’s a powder and inhaled into the lungs.  Bottom line, titanium dioxide is only potentially dangerous (speculation, not proven) in a powder form (which toothpaste isn’t) of nanoparticles (not used in toothpaste).  More research is needed and is currently underway, but at this point I just can’t justify being concerned about it.

If your toothpaste isn’t plain white then it’s probably some shade of blue, in which case the likely other color additive is FD&C Blue No. 1, also known as Brilliant Blue FCF, a very common food colorant.  The only concern ever noted by the FDA regarding its use is the potential for an allergic reaction in people with asthma.

Others

Flavorants: Various natural and synthetic additives, such as mint oil (often listed just as “flavor”).

Preservative: Sodium benzoate  (a common food preservative).

pH neutralizer: Sodium hydroxide (lye).

 

Granted there are likely other ingredients that have made it into a tube of toothpaste from time to time that are not explicitly listed here, but whatever they may be they would fall into one of the above categories.  I hope this article has been informative and provided some clarity in what to look for in a toothpaste.  If you have any questions, I’m certain your dental team will be happy to discuss further!

Patrick McGann, DDS

McGann Family Dental