Monday, July 18, 2022

Nature’s Dental Plan

The vast majority of people have no dental coverage, or at best have a less-than-stellar plan which only pays if you use their provider in the Outer Hebrides who works on alternate Tuesdays in April, although you’re still on the hook for a $5,000 deductible. Given a few recent discoveries, however, it looks like insurers could give us perfect teeth and yet save piles of money in the long run by taking cues from nature.

With a single up-front procedure, we could get self-replacing or unbreakable teeth like those found in certain animals. Of course, this would require the use of a gene-editing tool such as “Clustered Regularly Interspaced Short Palindromic Repeats,” or CRISPR. The acronym is fitting: one of its first miracles was an apple that stays crisper even if sliced and left out for ages. Nature’s answer to the Twinkie, I suppose.

Having shark teeth might be great. We’d have a never-ending supply of new choppers ready to move forward whenever we broke an old one biting a killer whale or opening a beer bottle. I imagine they’d be a hot item for punk rockers. Shark teeth ought to be a handy persuasion tool as well – just grin at your boss and watch how fast they approve your raise. Dating would suffer a bit, as we couldn’t smile on our profile pics, and there’d be awkward moments at meals when an old tooth falls onto your plate or stays behind in your pizza slice after a bite.

Metal is another option. After all, the villain “Jaws” in The Spy Who Loved Me film had steel teeth, and when thrown to his presumed death into a shark tank by James Bond, “Jaws” bit the shark, killing it. Sort of a riff on the rock-paper-scissors theme, where endless sharp teeth are deadly, but metal is more so. Nature has endowed a number of invertebrate species with teeth made of zinc, iron or copper. With a little gene editing we’d have a choice of materials in addition to a self-sharpening, virtually indestructible mouth. Metal heads first came to my attention in leafcutter ants, who pass their time snipping leaves into lace doilies or other inspired shapes. The ants then hike their leaf scissor-art to their underground nests and inoculate it with a fungus upon which the whole colony feeds.

Researchers long knew that leafcutter ants could shred foliage as well as human flesh with apparent ease, and that ant jaws stayed razor-sharp throughout their lives. How they kept their chops tip-top was a mystery for a long time because the working edge of an ant’s jaw is too fine to see with an electron microscope. Dr. Robert Schofield, a biophysicist at the University of Oregon, was able to crack the case using cutting-edge technology, you might say.

In 2021 he enlisted Pacific Northwest National Laboratory’s atom-probe tomography to reveal that ant teeth are made of protein fused to individual zinc atoms to form a nanoscale blade. Mechanical loads are evenly and perfectly distributed along the jaw. Bristle worms, found throughout the world’s oceans, have a different take on dentistry. There are about 10,000 species of these annelids, which originated some 500 million years ago and are mostly in the 10-cm size range. Like all segmented worms, their primary distinguishing feature is “creepiness.”

But last year, Professor Christian Hellmich and others at the Vienna University of Technology found that bristle worms’ jaws, typically infused with iron, though sometimes with magnesium or zinc, are unbreakable. But Hellmich says the fact there are metal atoms in the bristle worm jaw does not explain its freakish strength. Turns out the baby worms ooze a protein-metal flux while still in their cribs or wherever they sleep. This goo hardens into a bullet-proof (probably) amalgam that will deform under pressure, but flex back to its original shape.

Hellmich expects that studying bristle worm teeth will lead to high-strength materials being made “… more efficiently and environmentally friendly than we manage today.” An April, 2022 article in the journal Matter describes another oral overachiever: the bloodworm. Reaching 36 cm long, these residents of intertidal zones are both blood-colored and bloodthirsty, using their fangs of copper to impale prey. As article co-author Herbert Waite, a biochemist at University of California-Santa Barbara, put it, “These are very disagreeable worms…ill-tempered and easily provoked.”

A grumpy predator is bad enough, but this one keeps its head tucked inside its body until it’s ready to pounce, whereupon its jaws shoot out like the creature from the film Alien to bite its victim. Oh, and it’s venomous as well. Its gross-factor may be off the charts, but it gets high marks for mechanical engineering, too. Given their five-year lifespan and their inability to grow new teeth, bloodworms need durable dentures.

This is the first instance where melanin, which we know as a human skin pigment, has been documented as a structural material. Early in life, bloodworms make a slurry of proteins and melanin, which they infuse with copper scavenged from marine sediments. The result is a scimitar-shaped tusk that would have made any Bronze Age metalworker jealous. According to Waite, bloodworms could be a blueprint for “…how to make and engineer better consumer materials.”

Personally, I’d go for the bloodworm-teeth gene edits, as long as it doesn’t make my head retract in between meals. One thing about CRISPR editing is that changes to your genome are heritable. If you sign up for shark teeth, your kids will get them too. But maybe that’s better than having them go without dental coverage their whole lives.

Paul Hetzler is a former Cornell Extension educator. He takes excellent care of his tooth.

Photos at top: Bloodworm tooth photos by Herbert Waite.

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Paul Hetzler has been an ISA Certified Arborist since 1996. His work has appeared in the medical journal The Lancet, as well as Highlights for Children Magazine.You can read more of his work at or by picking up a copy of his book Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World

3 Responses

  1. Martie says:

    Hi, Paul –
    I love all your articles – and this one was especially sharp.
    I wonder if you could write about the effects of spongy moth caterpillar damage to the living things under all those defoliated trees. I see many re-foliating, but it’s still sunnier in the woods than usual. What effects do all those changes have on ferns, wildflowers, mushrooms, acorn and beechnut production, and all the critters that depend on that plant and fungal life?
    – Martie

  2. Charlie Stehlin says:

    “The vast majority of people have no dental coverage”

    That’s because teeth problems are as common as trash alongside our roadways. If they weren’t there’d be better coverage. Why would insurance companies be willing to cover expenses which they know will undermine their profits?

  3. Rita Davis says:

    This turned out to be pretty stupid.

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