Drill bits have to be replaced after showing signs of dullness. However, this doesn’t seem to be the case for teeth. Since they’ve been breaking down food and tearing packages since the dawn of time (and staying relatively intact for generations), how do they last so long? A group of researchers at the George Washington University in 2009 managed to crack the mystery open.
A closer look at the enamel, which is no less brittle than glass, revealed small cracks called enamel tufts. While appearing as a potential invasion point for tooth decay, the cracks actually help distribute the stress of chewing and gnashing across the entire tooth. Don’t worry; tufts are normal in teeth.
In other words, the enamel may crack like glass but it’s less likely to shatter under a biting force of up to 700 Newtons. That’s like more than 70 times the force exerted by the Earth’s gravity. It is believed that there are thousands of these micro-cracks in a single tooth alone, allowing the tooth to resist crushing forces.
Additionally, a basket-weave structure prevents the cracks from eventually splitting the tooth apart. Coupled with the body’s ability to mend itself, these cracks are kept from growing to the extent of permanent damage.
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