The end of fillings could be on the horizon after scientists found a way to successfully grow back tooth enamel. Although many laboratories have attempted to recreate the outer protective layer of teeth, the complex structure of overlapping microscopic rods has proved elusive.

Tooth enamel is the hardest tissue in the human body but it cannot repair itself when damaged, leaving people exposed to cavities and eventually needing fillings or a tooth extraction.

Now scientists at the Zhejiang University School of Medicine in Hangzhou, China, have found that mixing calcium and phosphate ions - both minerals which are found in enamel - with the chemical called triethylamine in an alcohol solution causes enamel to grow with the same structure as in teeth.

When the mixture was applied to whole human teeth, it repaired the enamel layer to a thickness of around 2.7 micrometres and achieved the same structure and orientation of natural enamel within 48 hours.

Writing in the journal Science Advances, Changyu Shao said: “Although a range of materials, such as composite resins, ceramics, and amalgam, have been developed for the restoration of tooth enamel, they have failed to achieve permanent repair because of the imperfect combination between these foreign materials and the native enamel.