Hard food protects the teeth

Too little wear and tear could be the main cause of widespread cervical defects

Collision detection (red) between the lower right prewooth teeth, the first molar and the upper right prewave teeth © Senckenberg
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Not too hard, but too soft food harms our teeth. Because the lack of wear leads to more tensions in the teeth and a higher load on the enamel. This, in turn, increases the risk of flaking enamel on the neck of the tooth, as German researchers have discovered, and explains why such cases accumulate. So: eating more carrots helps.

Our teeth are important and expensive. Today, aesthetic aspects are often in the foreground. A healthy dentition should have brilliant white tooth crowns and if possible no tooth wear. The evolutionary history of our teeth, however, teaches us something else. A natural tooth wear as an inevitable consequence of the food shredding and the habitat has accompanied the evolution of humans since time immemorial. Today, however, our teeth barely have anything to do: Our food - from burgers to fruit yoghurt - is usually soft and barely chewed; raw foods are rarely eaten by many of us.

But that seems to have consequences, as researchers now noted. "In our industrialized societies, we find a significant increase in cervical defects on the teeth, " explains Ottmar Kullmer from the Senckenberg Research Institute. He and his colleagues have therefore investigated in more detail whether this accumulation could be related to our altered eating and chewing habits.

Denture in 3D model

For their study, the researchers first determined the exact tooth-to-tooth contacts in human dentition using software developed by the Senckenberg Research Institute. Depending on where the teeth touch while biting, this also changes the distribution of stress in their interior. With this data, they fed a model. "The individual tooth contacts served as realistic as possible a computer simulation of the load distribution during biting, " explains Stefano Benazzi from the Max Planck Institute for Evolutionary Anthropology.

To compare the consequences of more or less wear on the teeth, they artificially abrade two of the premolars in one of their simulation runs, mimicking natural wear. This enabled the researchers to calculate how the load pattern changes with the continuous abrasion of tooth substance. display

More tension on non-worn teeth

The result: in the more worn teeth, the load is distributed much better over the entire crown, tensile stresses are significantly reduced. In the case of the non-worn teeth, on the other hand, significantly higher tensions occurred, especially in the cervical area. According to the researchers, this could explain why so many cases of blistered tooth enamel occur in this area today - people eat too little hard food.

"Evolution seems to have found a very successful compromise solution between material loss and the longest possible function preservation, " says Benazzi. But modern society counteracts this biological adaptation.

(Max Planck Society, 25.04.2013 - NPO)