Scientists in Canada and China have developed a hardy material using human bile acids, which they hope can be used to fill dental cavities.

Dental cavities are presently plugged using either mercury or plastic, which raises worries they could be potentially toxic.

In an article in ACS Applied Materials & Interfaces, the researchers described how they harvested bile acids and converted them into a hard, durable plastic that appear to resist cracking better than other materials that are now in use.

Bile acids are natural substances produced by the liver and are stored in the gallbladder to help digest fats.

"The new material appears stronger and longer lasting as well, with the potential for reducing painful filling cracks and emergency visits to the dentist," wrote the scientists, led by Julian Zhu at China's Shanxi University's department of chemistry.