Enamel is the hardest substance in your body. It’s a crystalline fortress protecting your teeth. But it has a fatal flaw: it cannot regenerate. The cells that build it vanish after the tooth is formed. Once it’s gone, it’s gone forever.

Or is it?

A team of researchers has developed a new technology that allows them to regrow human enamel, layer by layer. It’s not a cavity filler or anything like that. It’s a substance that “tricks” the tooth into rebuilding itself.

Enamel Problems

Microscopic images showing the enamel regrowing. Image from the research.

Half the people on the globe suffer from enamel problems. If left untreated, this can lead to cavities and tooth loss. We’ve gotten a lot better at patching these problems, but we can still only patch things up. The research team, led by Dr. Alvaro Mata at the University of Nottingham, wanted to see if we can actually fix enamel.

So, they looked at how enamel is first formed in the human body.

Enamel begins to form in humans during fetal development for baby teeth and continues after birth, until somewhere around age 7 or 8. During this process, enamel formation is tightly linked to a specific protein called amelogenin.

The enamel consists of a mineral called apatite, but it’s the amelogenin protein that controls the growth and organization of this mineral. Amelogenin separates the growing crystals and guides their ordered alignment; it is then largely removed, leaving behind mature enamel. Researchers can’t create amelogenin, but what if they could control something that triggers a similar response?

That’s exactly what they aimed for here. They engineered a new material based on elastin-like recombinamers (ELRs). Like amelogenin, these ELR molecules are disordered. The researchers hypothesized that they could force them to self-assemble into an ordered matrix that would mimic the natural one.

It worked.

A Scaffold For Enamel

The combination of calcium and drying acted as a trigger, causing the floppy ELR molecules to snap into organized, B-rich “ELR fibrils”. Simply put, the researchers created a synthetic matrix that imitated the structural and functional characteristics of the natural enamel-developing matrix. They made a scaffold on which the enamel could regrow.

So, they put it to the test. First, they tried it on extracted human teeth subjected to brutal erosion, with their enamel stripped away. They applied a thin coating of their new ELR solution and let it dry, forming the biomimetic matrix. This application takes just 3 to 4 minutes.

Then, they submerged the teeth in a mineralizing solution saturated with the building blocks of enamel: calcium, phosphate, and fluoride. What happened next is the heart of the discovery. The matrix didn’t just grow a random crust of mineral. It triggered epitaxial growth. This is a critical term. It means the new crystals grew directly from the old, damaged crystals of the tooth, like a new brick being laid perfectly on top of the last one.

The new growth was an exact, crystallographic continuation of the native tooth structure. Even in the experiment where the enamel had been completely destroyed, the mixture started regrowing enamel.

They then subjected this new enamel to a large number of tests. They wanted to see if it could withstand the same type of problems faced by natural enamel; it did. It fared every bit as well, and in some cases, even better. Notably, this new mineral turned out to be more chemically resilient when exposed to acid environments (like a soda).

So, When Can We Regrow Our Enamel?

There is, of course, one big caveat to all of this. The experiments were on *extracted *teeth. Our mouths are not sterile laboratory dishes. Our teeth are teeming with bacteria, constantly flushed with enzymes, and subject to the daily mechanical insults of chewing and grinding, not to mention all the saliva.

Researchers did replicate the experiment, using artificial saliva and human saliva instead of the mineralized solution. It worked just as well, which is extremely promising. But even so, this environment doesn’t fully recreate the complexity of our mouths. Moving to real teeth is a big hurdle, but it’s one that researchers are already approach.

Clinical trials are planned for early next year. Within only a few months, real people will get this treatment and, if everything goes according to plan, will regrow their enamel..

For the first time, we have a shot at truly healing a tooth. The era of “drill and fill” may finally be coming to an end.

The study was published in Nature.