Engines of Our Ingenuity

No. 1455:
DENTISTRY

by John H. Lienhard

Click here for audio of Episode 1455.

Today, we drill teeth. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

My visits to the dentist began in the mid-1930s. Dentistry in that remote age now seems like a brutal and primitive ritual. I was never given any anesthetic. Drills weren't air- or water-cooled. They generated heat, and heat meant terrible pain.

Tooth care is very old. Dental hygiene looms large in the ancient lore of India, where it was said of Buddha that he planted one of his tooth-cleaning sticks, and it grew into a tree.

The Romans did some cavity filling. They used lead. Lead fillings were widely used in 17th-century France. The use of gold foil traces to the ninth-century court of Haroun al-Raschid. It became widespread in 19th-century Europe. The trick was (and, in a few lingering instances, still is) to tamp in layer after layer of clean gold so each layer contact-welds to the one below it.

The foot-treadle-driven dentist's drill was invented in 1870. When drills were given electric power in the late 19th century, they took on more tasks than just drilling cavities -- polishing and shaping teeth, for example. In its early days, the power drill was called a dental engine. It also turns out that the rubber dam, which suddenly sprouted in so many dentists' offices after WW-II, was invented way back during the Civil War.

Anesthesia was a 19th-century invention. Its use spread after Queen Victoria accepted ether during childbirth. But Civil War surgeons still used it only occasionally. The pain-killers most used in dentistry before my lifetime were laughing gas for extractions and cocaine for drilling teeth.

Root canal surgery came into general use after WW-II. So I was surprised to find a long discussion of it in my 1911 Encyclopaedia Britannica. It was called devitalization of the pulp. But even if the process was known, we really recognized only one cure for a toothache when I was young. That was extraction. The article also suggests that crowns are best made from the healthy teeth of another living person. Failing that, bone, ivory, or the tooth of an ox will do.

America's first dental school was set up in 1840. By 1878, the number of dental students in America had grown to seven hundred, and we were living in a new age of dentistry. Thirty years later, seven thousand people were studying the field. So that brutal era of my childhood, with all its interminable unrelenting pain, was a world in ferment. It'd be twenty years before we could go to the dentist without expecting to do some serious suffering, but change was afoot. Many of today's procedures were known, and we were finally figuring out how to use them effectively.

I think about that as I doze in the dentist's chair, vaguely conscious of the muted hum of the drill. Criticize modern technology if that's your inclination. But please don't do it on a day that I'm visiting the dentist.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)


I obtained material for this episode from the 1911 and 1989 Encyclopaedia Britannica editions. As a matter of interest, the 1911 article is longer, and it says more about the history of dentistry than the 1989 edition.



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The Engines of Our Ingenuity is Copyright © 1988-1999 by John H. Lienhard.