We all wash ourselves teeth with the toothpastebut how many people know what it’s really for? Perhaps not everyone knows what toothpaste contains fluorinewhich forms a protective shield on the tooth enamel. This shield was born from one chemical reaction very precise, which transforms the hydroxyapatite of the enamel in a very compound more resistant to acidsfluorapatite.
But fluoride does not work alone: it is also present in toothpaste surfactantswhich help eliminate food residues, and the sorbitol/xylitol which works both as a humectant, to keep the dough soft, and to give a sweet flavour. Not to forget, then, the importance of toothbrushwhich mechanically removes plaque.
What are teeth made of: Enamel is made up of 97%. hydroxyapatite
Our teeth are covered in an outer layer called enamel, which is the hardest substance in the human body. Enamel is about 97% made from hydroxyapatite – in turn composed mainly of soccer And phosphate – while the remaining 3% is made up of water and proteins.
Now, there’s one key thing to know: lo enamelonce it has formed, it no longer regenerates. This is because the cells that produce it, the ameloblaststhey atrophy the moment the tooth emerges. So the enamel, theoretically, should last a lifetime. The problem is that we put a lot of things in our mouths every day (obviously food first and foremost) which, together with all the bacteria we naturally have in the oral cavity, can chemically attack the enamel.
The bacteria in our mouth: lo Streptococcus mutans
In fact, they live in our mouths hundreds of different species of bacteria. Be careful, it’s very normal, they are part of ours oral microbiota. Among these there is one that interests us in a particular way: lo Streptococcus mutans. This bacterium has a very specific ability: it can transform some simple carbohydrates of food, i.e. sugars such as sucrose and glucose, in acids.
In short: every time we eat something Sweetwe drink a sugary drink or simply eat bread or pasta, we are providing fuel to the bacteria in your mouth, which use it and produce acids.
These acids lower the pH of our mouth and, when the pH becomes too acidic (and therefore drops to pH 5.5 or even pH 5), hydroxyapatite of the enamel literally begins to melt.
In “scientificese” they say that the begins demineralization: the demineralization process is one of the first steps for it development of cariestherefore the holes that form on the teeth because the acids corrode them.
Be careful, however, ours saliva has a role very important to avoid continuous demineralization: in addition to an antimicrobial system to counteract excessive bacterial proliferation, our saliva contains Also calcium and phosphate. Saliva calcium and phosphate tend to spontaneously precipitate back onto the enamelreplacing those lost during demineralization. In this case, therefore, the reverse reaction also occurs, called remineralization.
Therefore both demineralization and remineralization constantly occur in our mouth: if these two reactions are balancedours enamel remains constantHowever, if demineralization prevails, the enamel begins to degrade.
This happens for various reasons, but mainly if we have a diet that is too rich in sugars or acidic foods: if the frequency with which we eat these foods is high and if there are too many bacteria, therefore our oral hygiene conditions are poor, demineralization wins over remineralization.
What is toothpaste used for and what does it contain besides fluoride
Toothpaste, as we were saying, contains fluoride, which serves to protect the enamel. Pure fluorine, however, is a toxic gas: this is why fluoride is present in the form of fluoride in toothpaste fluoridetherefore a fluorine salt. Specifically, the most used compounds are sodium fluoride, sodium monofluorophosphate and rendang fluoride, which have the ability to counteract demineralization.
Fluoride replaces hydroxide ions in hydroxyapatite, first forming fluorinated apatite and then, with another fluoride, forming fluorapatite. This fluorapatite, i.e. enamel with a fluorine shield, resists acid attacks much more than the original hydroxyapatite.
As a result, you will have one nail polish more difficult to dissolve and therefore less chance of tooth decay. Obviously this shield it is not perennialafter a while it goes away and therefore must be reapplied by brushing our teeth again.
Fluoride, however, is not the only ingredient in toothpaste. Among the most common and most present substances, in addition to water, there are for example the sorbitol and sodium lauryl sulfate. Sorbitol/xylitol has several roles, both as a humectant – therefore to keep the toothpaste paste moist – and to give the toothpaste its sweet flavour.
Sodium lauryl sulfate is a surfactant: to be clear, it is used for make foam and for eliminate food residuesespecially the fatty ones and to also reduce the bacterial load. Finally there are preservatives such as sodium benzoatevarious flavors and colorings, but they are not active ingredients.
Obviously the role of the toothbrush should not be forgotten: the mechanical action of the bristles is essential for removing the dental plaque e larger food residues.
