Mad About Science: Toothpaste

By Brenden Bobby
Reader Columnist

Science isn’t just about explosions, lasers and slinging billionaires into space. Sometimes, science is about keeping your mouth healthy and minty fresh.

Mint-flavored tooth care has an extremely long history, though toothpaste as you know it is a relatively recent invention.

There is evidence that goes back to at least the Middle Ages of common workers applying a mixture of ground herbs to their teeth to kill bacteria, improve freshness of their breath and sweep away bits of food caught between their pearly whites. The image of everyone in feudal Europe walking around with a mouth full of rotted out chompers and horse-slaying halitosis is largely a misconception of history — but, by the same token, it’s not something that was entirely false.

“History is written by victors,” is a quote famously attributed to Winston Churchill (though its origins are unknown), and it applies to the subject of tooth care in much the same way as a history of human conflict. Medieval history was mostly recorded by the clergy and aristocracy — this created two snowballing misconceptions that continue today.

The first misconception is that only members of the aristocracy and clergy were literate. Literacy, while considerably lower than it is today, was still a central part of commoners’ everyday lives throughout the medieval period (roughly identified as spanning from the late-400s to late-1400s C.E. 

Commoners needed to be able to read road signs when traveling to trade their goods; they also needed to be able to write down things to remember for later — especially if “later” was a full season away. While not extremely widespread before the invention of Gutenberg’s printing press in 1440, villages and indeed some homes would possess copies of the Bible in English, French, Greek, Italian or Latin. Comprehension of the text was very likely similar to most people who read the Bible today: While the layman may not have total scholarly understanding of the text, they were able to extrapolate and model their daily lives and behaviors around the core values of the book, recite psalms and prayers, and even reference the text.

The misconception of medieval illiteracy being widespread is likely a mixture of things. Paper as we know it, pulped from plant fibers, was an extreme rarity in Europe, where vellum or the skin of a calf or lamb was more typical. Calves and lambs were expensive commodities and out of reach of most people of the time. Commoners also didn’t have the means to preserve texts in the way that the aristocracy or the clergy did, and the likelihood of their own personal writings decaying was considerably higher than someone who devoted their lives to the preservation of knowledge and faith. 

Additionally, the aristocracy, much like the contemporary ultra-elite, likely looked down on the common man or woman and recorded their own perceptions of the layfolk rather than a truly accurate representation of their subjects. Those with the means — the “victors” — managed to preserve their version of people, places and events and, with very little evidence to prove the contrary, those impressions have been taken at face value.

Tooth care, unlike the ephemeral art of the spoken and written word, is much easier to examine on the archaeological record. Here, privilege and wealth worked contrary to the legacy and wellbeing of the elite.

The medieval upper crust dined on a wide range of luxuries, with sugar being chief among them. Sugar, derived from fruits like apples, grapes and plums throughout much of France, is a great source of energy for both humans and the bacteria that live in our mouths. 

(Bonus fact about plums: They’re originally from China, but found their way to Europe during the Middle Ages.) 

Our brains are wired to seek sugar, and we will crave it once we get a taste. Sugar is a great caloric energy source and keeps us energized and our brains working, but the bacteria in our mouths love it just as much and will work quickly to use it as an energy source to create more bacteria. Bacteria are hardly discerning when it comes to consumption, and will begin to break down and devour anything they can to replicate. Left unchecked, they will cause our teeth to decay and create cavities, infecting our flesh and blood to create toothaches or even full-body sepsis.

Medieval commoners, on the other hand, did not share in the luxurious, sugar-laden diet of the nobility. Most common meals were hardy, filled with grains and root vegetables. Remnants of mashed and shredded herbs have also been found stuck between the teeth of medieval layfolk, and it’s believed that they used these concoctions as a form of proto-toothpaste, similar to how we use minty chewing gum today. 

A mix of the herbs’ antibacterial effect, their pleasant smell and mild abrasive effect helped scrub away bacteria before they could cause the kind of damage that nobility regularly experienced.

Toothpaste you might recognize today is an evolution of the medieval chewing herbs. In the 1700s, a form of toothpaste was created using herbs, resinous plants and burnt bread. By the American Civil War, people began mixing this dental paste with soap, and then eventually chalk. 

This chalky substance mixed with the chemical fluoride is the basis for what we use today. These chemicals work with chemicals in the enamel of our teeth to kill bacteria, while the act of brushing abrasively sweeps away the living and the dead bacteria. Mixing in mouthwash, which is often a very light mixture of alcohol, helps kill off any stragglers and slows tooth decay while washing it all away and keeping your breath fresh.

It’s amazing how much history is hidden under our noses — literally.

Stay curious, 7B.