False Teeth: Hippo Ivory, Porcelain and a Patent Murder

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Welcome to Origins. In this program we explore the technological and scientific roots of the modern world. Let's begin.

On Easter Sunday morning in 1879, a dentist named Samuel Chalfant walked into a hotel room in San Francisco to settle a business dispute. The man waiting for him was Josiah Bacon, treasurer of the company that held the patent on rubber denture plates. Chalfant drew a pistol, and Bacon died from a single shot to the abdomen. Chalfant said the gun went off by accident. A jury convicted him of second-degree murder, and he was sent to San Quentin.

It's a strange thing to kill a man over. To see how false teeth came to matter that much, it helps to look at what people have been willing to put in their mouths.

The oldest well-known replacements come from the Etruscans, in what is now central Italy, starting in the seventh century BCE. Twenty-one of their appliances are known. Each is a band of very pure gold, wrapped around healthy teeth to hold a replacement riveted in place. The replacements were usually bone, ivory, or a recycled human tooth, sometimes the wearer's own. They were too delicate for serious chewing. The scholars Marshall Becker and Jean Turfa note that every one appears to have been made for a woman, and they argue that many of the missing teeth were pulled on purpose, perhaps to mark mourning, coming of age or status. Whatever the reason for the gap, the first false teeth seem to have been mostly about how a smile looked.

Jump ahead more than two thousand years. As sugar became cheaper in eighteenth-century Europe and its colonies, more people lost their teeth, and replacing them became a trade. A denture-maker carved a base from ivory, often hippopotamus, and fitted it with teeth. Dentists of the day called human teeth "at all times preferable where they can be had." They came from the poor, who sold them, and from the dead.

George Washington had a tooth pulled in 1756, at the age of twenty-four, for five shillings. He kept some of the teeth he lost after that in a desk drawer at Mount Vernon, hoping they could be set into new dentures. By his inauguration in 1789, he had one working tooth left. Over the years his dentures combined human teeth, cow and horse teeth, hippopotamus and walrus ivory, lead and gold, with springs that pushed the upper and lower plates apart against his gums. In 1797 he complained to his dentist, John Greenwood, that a new set made "both upper, and under lip to bulge out, as if swelled." The famous wooden teeth never existed. Stained ivory may be where that legend came from.

There is a harder entry in the Mount Vernon account books. In May of 1784, while Washington was away, his plantation manager paid six pounds and two shillings to enslaved people for nine teeth, on account of a French dentist named Jean-Pierre Le Mayeur, who was advertising tooth transplants in Alexandria and buying teeth. Their names weren't recorded, and neither was whether they had any real choice. Whether any of those teeth ended up in Washington's own mouth is unknown. The entry still shows how the market worked: the teeth flowed from people with the least power toward people with the most.

Ivory had another problem, and a man near Paris felt it every day. Alexis Duchâteau was an apothecary in Saint-Germain-en-Laye, and he wore dentures of ivory and natural teeth. They deteriorated, and they smelled. In 1774 he asked a Paris porcelain maker named Guerhard to fire him a set from porcelain. The French dentist Pierre Fauchard had suggested the idea back in 1728, but no one had made it work. Guerhard's set had defects, and Duchâteau wasn't satisfied.

Duchâteau turned to a young dentist, Nicolas Dubois de Chémant, who bought the rights and kept going. In 1786 he took wax models of dentures to the royal porcelain works at Sèvres. Hard porcelain failed him. A softer paste, tinted with colors he mixed himself, succeeded. He called it incorruptible mineral paste, meaning it would never rot. One Sèvres workshop chief later testified that in forty-six years at the factory, he had never seen anyone make teeth out of porcelain except Dubois de Chémant.

In September 1791, with the Revolution well underway, Louis the Sixteenth granted him a patent. Within months a group of Paris dentists sued to strip it from him, and old Duchâteau joined them, arguing that the discovery had been his and that the so-called mineral paste was ordinary soft porcelain. Dubois de Chémant also patented his teeth in Britain, where he bought much of his porcelain from Wedgwood.

Those early porcelain dentures were fired as a single piece, teeth and gums together. In 1808, an Italian dentist working in Paris, Giuseppangelo Fonzi, published a method for making porcelain teeth one at a time, each with a platinum hook baked into it, so it could be fixed to a base and replaced on its own.

Porcelain took decades to win, and human teeth stayed in demand. After the Battle of Waterloo in 1815, so many teeth were pulled from the dead that the market was flooded, and dentures made with human teeth came to be called Waterloo teeth.

That left the base. The best bases were gold or silver, and a full set could cost seventy-five to a hundred and fifty dollars, far beyond most people. Then came vulcanized rubber. Charles Goodyear had found in 1839 that sulfur and heat make rubber stable, and his brother Nelson worked out a hard version. A dentist could press soft rubber onto a plaster cast of a patient's gums, set porcelain teeth into it, and cook the whole thing under pressure for an hour or two. The plate came out hard and fitted to that one mouth. A full set could now cost about thirty dollars.

A patent on rubber denture bases, filed in 1852 by a dentist named John Cummings and granted in 1864, ended up with the Goodyear Dental Vulcanite Company, run by Josiah Bacon. Bacon charged dentists an annual license of thirty-five to fifty dollars and a royalty on every set. He hired agents to catch unlicensed dentists, sent a woman in posing as a patient, and set up a front company selling cheap rubber to find out who was using it. The campaign ran for thirteen years, and it ended in that hotel room.

The patents expired in 1881, and any dentist could use the rubber without paying for a license. In the twentieth century acrylic plastic replaced the rubber, but the method held: a cast of the gums, a molded base and a row of manufactured teeth.

Across that whole line, each era built a mouth from whatever it could get: gold for Etruscan women, ivory from hippos, teeth from the poor, the enslaved and the dead, porcelain from a royal factory, rubber from a patent fight. The modern denture is cheap, ordinary and made from nobody's teeth. That took about two and a half thousand years.

That's our show for today. Thanks for listening to Origins.