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.
“However, the layer newly regrown by remineralization can be integrated into native enamel such that the repair would be permanent, and this process may be developed as an effective cure for enamel erosion in clinical practice.
“We believe this will be developed as a promising enamel repair material for dental applications in the future.”
Currently there is nothing to be done to repair damaged teeth apart from fillings or crowns and many scientists are looking for ways to grow back teeth.
In 2017 King’s College London discovered that the drug Tideglusib stimulates the stem cells contained in the pulp of teeth so that they generate new dentine – the mineralised material under the enamel.
Teeth already have the capability of regenerating dentine if the pulp inside the tooth becomes exposed through a trauma or infection, but can only naturally make a very thin layer, and not enough to fill the deep cavities caused by tooth decay.
Scientists showed it is possible to soak a small biodegradable sponge with the drug and insert it into a cavity, where it triggers the growth of dentin and repairs the damage within six weeks.
Earlier this month scientists at the University of Plymouth discovered a new group of stem cells which form skeletal tissue and contribute to the making dentin. They also showed that a gene called Dlk1 sparks the stem cells into action, so they can mend damage such as decay, crumbling or cracked teeth.
Commenting on the new Chinese research Professor Damien Walmsley, Scientific Advisor for the British Dental Association, said: “This is exciting but it’s still a very long way off. “A lot of other things need to come together before we can successfully grow back a tooth.
“I think we’ll eventually get there in ten, 15, 20 years.”