And because our ancestors weren’t dumb, they came up with solutions. And now we’ve found the oldest example of one of these solutions: fillings. The newly discovered fillings were placed 13,000 years ago and were made of tar, along with some minor additives.
Their Teeth Have a Lot to Say
Archaeology provides us many testaments to the durability of human teeth. Because our teeth are the most highly mineralized tissues in our body, they are often the last remnants of long-dead humans. In fact, there are some long-gone human species that are known only by their teeth.
And that’s the case in this find: two incisors are all that remain from these prehistoric people. But that doesn’t mean we don’t know much about them: their teeth have a lot to say (even if their mouth is long gone).
The teeth were discovered at a site near Lucca in Italy, and they knew that people in this region had been drilling teeth since about 1000 years earlier. That discovery was equally revolutionary–it pushed back the history of dentistry by about 5000 years.
And now we know that these dentists weren’t just drilling out decay: they were restoring teeth, too. These newly discovered teeth had remnants of tar (bitumen) around the drilled holes. Dating showed that the tar was placed at the time the tooth was drilled. The tar also included traces of animal hair and plant fibers. These were also placed at the time of the filling, and not a remnant of later meals eaten after the filling was placed.
This new filling is about 6500 years older than the previous oldest example of a filling. That filling was made of beeswax, although the tooth had not been drilled before the filling was placed.
With their limited access to materials, we see ancient dentists making the same compromises that people made with metal amalgam fillings. The benefits of tar as a filling material are obvious: it’s malleable, creates a seal, and resists dissolution by saliva. In many respects, it’s a better filling choice than beeswax, which would probably have needed to be replenished regularly.
Tar does have some drawbacks as a filling material, though. It would have to be melted to be applied to the tooth, which typically happens around 120° F, which might be a little hard on teeth in the absence of anesthesia. (Although, considering the tooth was just drilled out with a stone bow drill, the patient might be passed out already.) This may not actually be that much worse than metal amalgam fillings, which had to be pressed in firmly to make sure they fill the cavity.
And tar is basically the same cosmetically as an oxidized metal amalgam filling, which turns black.
And then there’s the taste that probably lingers in your mouth. People may have gotten used to it, the way many people get used to the metallic taste of amalgam. Or maybe that’s why this particular practice died out: the Egyptians didn’t practice this kind of filling, although they did perform other kinds.
Today, of course, we have much better technologies for dental fillings. Composite fillings are a quick, durable, inexpensive, and healthy filling option. And ceramic fillings are even more attractive and durable. And neither of them tastes like tar!