So, the other week I was in the store pur­chas­ing some tooth­paste. Now tooth­paste, at least in Amer­i­ca, is a great exam­ple of that phe­nom­enon of a huge num­ber of indif­fer­en­ti­at­able choices you often get when shop­ping at a typ­i­cal gro­cery store. There are maybe a dozen brands of tooth­paste and each brand has maybe a dozen prod­ucts all adver­tis­ing slightly dif­fer­ent advan­tages in the realm of tooth care. One tube of tooth­paste offers defense against cav­i­ties while another adver­tises that it will pre­vent plaque build up. Now, never mind the fact that the default expec­ta­tion is that all brands of tooth­paste will help pre­vent cav­i­ties, there is really no way for the casual shop­per to really eval­u­ate the claims of these dif­fer­ent products.1 If one uses one brand of tooth­paste for a year and never gets a cav­i­ty, there is gen­er­ally no way to know if it was that tooth­paste which pre­vent­ed, or if any brand would have done.

Now, I am cog­nizant of this issue and usu­ally just buy the cheap­est tooth­paste available.2 I typ­i­cally assume that most brands of tooth­paste are actu­ally pretty sim­i­lar and that it does­n’t mat­ter which I choose. Any­way, while shop­ping for tooth­paste the other week, the thought occurred to me that this assump­tion was, in fact, an assump­tion and that I could prob­a­bly check whether this was the case. So I took a moment to look at the ingre­di­ents list of a few pop­u­lar brands of tooth­paste.

I noticed right away that they all seemed to have the exact same soli­tary active ingredient: sodium fluoride. “Ah ha!” I though, “I’m more right than I know!” But then I looked again and noticed that there was also an inac­tive ingre­di­ents list and that this list did vary from tooth­paste to tooth­paste. It var­ied sig­nif­i­cant­ly. Now, these are inac­tive ingre­di­ents so it was prob­a­ble that they had no effect on the effi­cacy of the tooth­paste, but you never know until you check. So I went a lit­tle over­board and pho­tographed the ingre­di­ents list of every brand of tooth­paste in the gro­cery store that day and com­piled a list of every ingre­di­ent that I found included in some brand of tooth­paste. I then researched each of these ingre­di­ents to deter­mine what the prob­a­ble usage was. I’ve com­piled the full list as well as there prob­a­ble usages into a list (at­tached to the end of this blog post).

There were actu­ally five active ingredients:

sodium fluoride              tooth-hardener
sodium monofluorophosphate   tooth-hardener
stannous flouride            tooth-hardener
potassium nitrate            anti-sensitivity
triclosan                    antiseptic

No tooth­paste used all five ingre­di­ents at once but some had two. Typ­i­cally one of either sodium fluoride, sodium monofluorophosphate, or stannous flouride was present with, option­al­ly, either potassium nitrate, or triclosan as a sup­ple­ment. Now, if you’ve ever been to the den­tist, you’ve prob­a­bly been through the ‘flu­o­ride mouth­wash’ rit­u­al. If not, per­haps you’ve heard of flu­o­ride being intro­duced to the water sup­ply. Either way, the actual chem­i­cal being used was likely sodium fluoride. If not, it was prob­a­bly either sodium monofluorophosphate or stannous fluoride. Either way, the pur­pose of flu­o­ride, in den­tal care, is to harden teeth by con­vert­ing apatite, a cal­cium com­pound that is one of the main com­po­nents of your teeth to fluorapatite, which is a ver­sion of apatite that is more resis­tant to the acid pro­duced by the microbes that live in your mouth. 3

So, the obvi­ous con­clu­sion is that the main action of most tooth­pastes is just flu­o­ride ther­a­py. You can rinse with flu­o­ride mouth­wash to get the same (ac­tu­ally stronger!) effect. How­ev­er, there is more. Potassium nitrate, also known as salt­peter, is a chem­i­cal com­monly used in the mak­ing of bombs and incen­di­aries. When applied to sen­si­tive teeth, appar­ently it crys­tal­izes over the exposed nerves and helps to pre­vent those nerves from get­ting trig­gered. Potassium nitrate was found in most tooth­pastes adver­tised as being for sen­si­tive teeth. Not all included it though and those that did­n’t used stannous fluoride.

The final active ingre­di­ent is triclosan. This is actu­ally an antibac­te­r­ial and anti­fun­gal chem­i­cal. It’s present in a lot of antibac­te­r­ial soaps. It’s pur­pose in tooth­paste is to pre­vent and fight infec­tions, such a gin­givi­tis.

That’s it for the active ingre­di­ents. There is still the prob­lem of the inac­tive ingre­di­ents. It seems that the major­ity of inac­tive ingre­di­ents are some vari­ety of ‘thick­en­er’, ‘foamer’, or ‘gelling agent’ to give the tooth­paste its typ­i­cal ‘paste’ qual­i­ty. There was a lot of vari­ety in what thick­en­ers were used, but I doubt that they made much of a dif­fer­ence in the qual­ity of the tooth­paste. After that, many of the ingre­di­ents were col­orants, arti­fi­cial sweet­en­ers, or preser­v­a­tives, none of which should have an effect on tooth health either.

So it would seem that I was cor­rect in my first assump­tion that the inac­tive ingre­di­ents did­n’t mat­ter, except that I did across a small list of ingre­di­ents that actu­ally weren’t thick­en­ers, col­orants, or sweet­en­ers. These chem­i­cals were:

calcium peroxide           tooth whitener
cetylpyridinium chloride   antiseptic
cocamidopropyl bedaine     antiseptic
hydrated silica            abrasive
mica                       abrasive
sodium bicarbonate         bleaching agent, antiseptic
sodium hexametaphosphate   anti-staining, tarter prevention
sodium hydroxide           cleaning agent
sodium lauryl sarcosinate  cleaning agent, polishing agent
sodium lauryl sulfate      antiseptic
zinc citrate               anti-plaque
zinc phosphate             dental cement (glue)

So how about that? Active, inac­tive ingre­di­ents. Two of these ingre­di­ents are hydrated silica and mica and are used as abra­sives in attempt to help scrape plaque off teeth. Per­son­al­ly, I thought that that was what the tooth­brush was for, but per­haps this helps. Calcium peroxide is used to whiten teeth with­out actu­ally bleach­ing them. Appar­ently it replen­ishes the cal­cium in the teeth. Other chem­i­cals, such as cetylpyridinium chloride and sodium lau­ryl sulfate are anti­sep­tics just like triclosan that kill microbes and hope­fully pre­vent gin­givi­tis. Some of the chem­i­cals, such as sodium hydroxide are cor­ro­sive clean­ing agents (sodium hydroxide is used in drain clean­er­s!) and seem like they might be overkill for your teeth.

So all that is very inter­est­ing and I now have a much bet­ter appre­ci­a­tion for what goes into tooth­paste and how it’s sup­posed to work. I sup­pose that if I could pick my ideal tooth­paste, it would con­tain stan­nous flu­o­ride, tri­closan, and cal­cium per­ox­ide as my teeth aren’t sen­si­tive and I’d avoid some of the more caus­tic chem­i­cals as I sus­pect they might be counter pro­duc­tive, (though I hon­estly have no idea if they actu­ally are.) In the end though, most tooth­pastes seem to do mostly the same thing with slightly dif­fer­ent ingre­di­ents, but with sig­nif­i­cant vari­eties in for­mu­la­tion. At least now the adver­tise­ments on the pack­ages make a lit­tle more sense to me.

Full Ingredient List



  1. With the exception of anti-sensitivity toothpaste where I imagine a person with sensitive teeth could tell if the toothpaste helped. 
  2. This is Aim brand toothpaste in my local grocery store. 
  3. It appears that sodium monofluorophosphate and stannous fluoride are more effective than sodium fluoride

Last update: 22/10/2015

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