Engineered dental coating found harder than tooth enamel

Scientists in Russia and Egypt have engineered a synthetic dental coating said to exceed the hardness of natural tooth enamel.

Supported by a grant from the Russian Science Foundation, the joint research team comprised of scientists from the Research and Education Center “Nanomaterials and Nanotechnologies” of Ural Federal University, Voronezh State University, Voronezh State Medical University, Al-Azhar University, and the National Research Center (Egypt).

Emulating the microstructure of tooth enamel

By tweaking the composition of hydroxyapatite, a naturally occurring material for mineralizing bones and teeth, the scientists were able to emulate the microstructure of natural enamel in a new type of dental coating. In so doing, they claim to have developed a breakthrough material that offers superior strength.

This is no easy feat, considering that the tooth enamel is the hardest tissue in the human body. According to the researchers, this improved composition of the material could have far-reaching applications in materials science and regenerative medicine.

The researchers administered complex of amino acids – that aids in the natural repair of bone and muscle structures – on the hydroxyapatite. After doping, these acids, including lysine and arginine, result in a mineralized layer with properties that resemble the main component of natural enamel. By applying the material to healthy teeth, the researchers observed its ability to bind to real dental tissue.

Biomimetic mineralized layer

Using chemical imaging, field emission electron and atomic force microscopy, the scientists investigated the properties of the new material. They found a mineralized layer (between 300 – 500 nanometers) thick forming a nanocrystal structure in line with that of apatite crystals in natural enamel.

Measured on the nanoscale, they found the new coating exhibited even greater hardness than natural enamel.

“We have created a biomimetic mineralized layer whose nanocrystals replicate the ordering of apatite nanocrystals of tooth enamel,” said study author Pavel Seredin.

“We also found out that the designed layer of hydroxyapatite has increased nanohardness that exceeds that of native enamel.”

New material also reduces teeth sensitivity

Published in Results in Engineering, the experimental results of the study revealed that the new coating can also be used to reduce teeth sensitivity in cases involving enamel abrasion, or following erosion or improper diet. 

The team hopes to explore new applications for the material such as applying the material to larger defects, including cracks and fractures.