A University of Western Australia study reveals for the first time the secret to the success of sheep teeth, which have to chew for a lifetime on the tiny glass crystals found in grass: they’re not as strong or hard as human teeth.

That’s right, when it comes to the demanding conditions under which sheep eat, strength is actually a weakness.

Success through Failure

Although we have long known the basic anatomy of sheep teeth, little investigation has been made into how these teeth are able to hold up under the demanding condition of constantly chewing on glass. The glass crystals, technically known as phytoliths (“plant stone”), were incorporated by plants to protect them from overconsumption by herbivore, make for significant wear on the teeth of all plant-eating animals.

Sheep and similar ruminants counteract this by having teeth that are actually designed to break, so when it happens they don’t look for a sheep dentist to restore their crown. Part of the crown of the sheep tooth breaks off, exposing the dentin in the middle of the tooth, and creating sharp edges on either side of the tooth that can cut through the grass. The dentin underneath is even less strong, and is designed to slowly wear away, resulting in the tooth being worn down. This wear slowly grinds away the tooth, which continues to emerge from the jawbone as the sheep ages.

Strength vs. Toughness

To understand the properties of sheep teeth that make them successful, researchers at UWA tested the strength and hardness of sheep teeth and compared them to human teeth. They found out that the enamel is 30% weaker than human teeth and 9% softer.

However, the weakness is actually an asset to sheep. Strong materials tend to be brittle, making them more likely to fracture, and less likely to stand up under the strains of the constant wear from the crystals in grass. Although the fracture and wear of teeth is anticipated and essential to the development of sheep teeth, the teeth still have to hold up long enough for the sheep to mature and reproduce, something it is able to do with its weaker teeth.

If You Break a Tooth

Unlike sheep teeth, human teeth are not designed to break and continue to function. If you experience a broken tooth–or lose a tooth–it’s important to see a dentist right away to prevent further damage.

For help with a chipped, cracked, or damaged tooth, please contact My Hills Dentist in the Baulkham Hills area of Sydney today.