Today’s toothpastes do many things: there are whitening, for sensitive teeth, anti-stains … But all of them share most of the ingredients, as we can read in the small print that should be seen on the box when we buy it. And as required by law, the list must begin with the most abundant ingredient and end with the one with the least proportion. Well, the most abundant – between 30 and 45% – is water : almost half of what we buy in toothpaste we would get for much less money by opening the tap. The second most abundant substance is abrasive, that substance capable of dealing with tooth enamel, the hardest substance we have in the body, more than bones or nails. Here we will find quartz or plaster , the same one that is used to write on the blackboard and whiten the walls. The abrasive particles, as small as the dirt particles in a garden, are responsible for polishing the teeth during brushing as when the rock is ground in a quarry.
The hallmark component of toothpaste is fluorides, which help rebuild (remineralize) tooth enamel , which weakens over time. The first to be used was stannous fluoride because, unlike another compound, sodium fluoride , it did not lose effectiveness with the abrasives that were used at the beginning, essentially calcium phosphate (which is also used in the production of fertilizers, bread baking and cheese making). Fluorides work best in the presence of surfactants or surfactants like sodium lauryl ether sulfate or ammonium lauryl ether sulfate (which are also used as foaming agents at ‘foam parties’), which also help wash away brushing debris.
To the toothpaste they add antifreeze so that it does not dry out
The next substance to be added is for purely cosmetic reasons. We all like our teeth to be very white, right? Well, this is achieved with sodium bicarbonate peroxide . The bicarbonate serves, in addition to being abrasive and antibacterial, to give that feeling of ‘clean mouth’. Since it releases carbon dioxide in the presence of acids, it helps to make more foam; something that is not necessary but, would we buy a toothpaste that makes little foam? That helps to sell. Peroxide (like hydrogen peroxide) is responsible for teeth whitening. Another is titanium oxide , the same material used to make white paint on walls white. With it the yellow of the teeth is covered and they appear with a lustrous white color. Of course it has its drawbacks. As titanium oxide is soluble in water, it is shed from the teeth during the following hours and the white color of the teeth disappears. But all this has already been thought out: nobody goes down the street looking at how white their teeth are every hour, we only do it when we have finished brushing. What’s more, some manufacturers even incorporate optical brighteners , the same ones used in laundry detergents, to ensure that it is whiter than white.
So that the paste does not dry out and is soft, a mixture of glycerin glycol is added – the ingredient most used in car antifreeze – a seaweed and paraffin oil, the fuel for camping lamps.
Now comes the secret compound of toothpaste brands and for which there are real battles: the air freshener . Obviously, because the previous mixture is quite disgusting. And so that such a mixture does not become a paradise for bacteria, formaldehyde, the disinfectant used in laboratories, is added.
