Image: ShutterstockAs the hardest substance in the human body, enamel covers the crown of a tooth, protecting the sensitive dentine beneath. Each day, teeth are subjected to the chomping and chewing of food substances, from soft bananas to hard candy. According to Live Science, the “basket-weave-like microstructure” of enamel is behind a tooth’s durability.  

However, enamel isn’t capable of regenerating. Once eroded, it’s gone.

In a proof-of-concept study, ETH Zurich scientists used magnetically guided materials to develop a biomimetic tooth as durable as the real deal. The material’s structure is based on the principles behind teeth and seashell construction.

“The profile of hardness and toughness obtained from the artificial tooth corresponds exactly with that of a natural tooth,” said André Studart, a professor of complex materials at ETZ Zurich.

Using a technique called magnetically assisted slip casting (MASC), the researchers created a plaster mold, and poured in a suspension containing aluminum oxide platelets. Pores in the mold absorb liquid from the suspension, causing the materials to harden. During the process, a magnetic field is applied to create a layer-like structure in the material. Once solid, the platelets maintain orientation. Through the magnetic manipulation, each layer can have different properties, thus allowing researchers the ability to replicate the natural tooth layers.

Using a human wisdom tooth as a model, the researchers created a fake tooth. Two suspensions were created, one with aluminum oxide platelets and glass nanoparticles and one with just aluminum oxide platelets. The suspension containing the glass nanoparticles was aligned vertically to replicate enamel, while the suspension with only aluminum oxide platelets was aligned horizontally to replicate dentine. Afterwards, the tooth was sintered to densify and harden the material. Remaining pores were filled with a synthetic monomer.  

Though successful, “the appearance of the material has to be significantly improved before it can be used for dental prostheses,” said Studart.

The researchers have patented one part of the MASC process, the magnetization and orientation of the ceramic platelets.


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