This is Scientific American's 60 Second Science.

I'm Christopher Intagiyata.

Of all the stuff you can buy on eBay, here's a new one, human teeth.

I think I probably averaged maybe $5 a tooth.

Kelly Keenan, a biochemist at Stockton University in New Jersey.

She chased down the chompers to investigate what saliva, a liquid mixture at the pH and with salts you'd find in regular spit.

Treatments complete, she extracted proteins from the teeth,

and found that the more rounds of whitening the teeth experienced,

the fewer proteins she could recover recover because hydrogen peroxide in the whitening

strips was snipping chemical bonds.

The bigger picture is that hydrogen peroxide can penetrate the enamel and dentin and it can cause your proteins to break down and smaller pieces are removed from those proteins.

She and her undergraduate students presented on that research at the 2019 experimental biology meeting in Orlando.

Now, this is just a preliminary study, and the pulp of your teeth can replenish proteins in the dentin,

though not the enamel, so it's unclear whether these effects would cause permanent damage in real

living teeth.

One thing's for sure though. Supplies of teeth for experiments seem to be plentiful.

I think I bought a set of 15 and the person's like, let me know if you need more. And this person

also claimed that the teeth were from his mouth, which you don't have any more to go.

That's true.

Thanks for listening. For Scientific's 60 Second Science, I'm Christopher

and Deliata.