Tel Aviv Scientists Could Make Root Canals History

New nano-filling prevents the secondary tooth decay that takes place beneath cavities; could reach trial stage in a year or two

Dentist attends to a patient at his clinic in Managua, Nicaragua, March 27, 2019.
Oswaldo Rivas/Reuters

Sorry, sadists: You may want to find a more dependable profession now that Tel Aviv University has invented fillings that prevent tooth decay from recurring. The study was published in ACS Applied Materials and Interfaces.

It is true that clinical trials of the nanostructure on humans aren’t even on the horizon yet, Dr. Lihi Adler-Abramovich tells Haaretz. But assuming the safety tests pan out and a corporate ally comes on board, theoretically their breakthrough invention could reach human trials in a year or two, she says.

Tooth decay has been a problem since teeth began to evolve. Caries were even identified in a flat-headed omnivorous lizard named labidosaurus hamatus that lived 275 million years ago and must have been in horrible pain.

But the scourge of modern cavities resulted from two things: Around 12,000 years ago, humans transited from a hunting-gathering lifestyle to farming; and, more recently, we began to live longer.

Archaeological research into Neolithic communities around the world has found that the transition didn’t increase our disease burden, but changed it. Cavities weren’t unknown before, but they became much more common — and the discovery of sugar helped not at all. Then the discovery of modern medicine extended our lifespans by decades.

So, chewing on wheat and candy, cavities have become among the most widespread bacterial conditions in the world. Then, as those of us beyond our teen years have discovered, we develop more cavities beneath the fillings. That is called “secondary tooth decay.”

Secondary decay can ruin dental restoration. It affects an estimated 100 million patients a year at an estimated cost of over $30 billion, the Tel Aviv team says.

So Adler-Abramovich and the team set out to invent a filling that would prevent secondary tooth decay and that didn’t have toxic effects like certain old-school metal fillings.

The result was a brand new composite material that is intrinsically antibacterial.

Which means what?

Testing treated extracted human teeth for bacteria repellent.
Lee Schnaider

Bacteria love our fillings, Adler-Abramovich explains. They adhere to them and, over time, that composite material of which our fillings are composed shrinks. Bacteria love those cracks and crannies, and thus we develop yet more rot around and underneath our cavities.

But their new material contains “antibacterial nano-assemblies” and bacteria do not cleave to it, she tells Haaretz. They hate it.

So the material is not antibiotic in the sense that it kills germs (which couldn’t last long). It repels bacteria, and theoretically that attribute could last forever. Longer than you will, anyway, for all our augmented lifespans. They have checked its deterrent property over months, and its still works.

All this work has been done in extracted teeth in the lab, nary a mouse model in sight. That day will come, though: Before human trials can begin, animal studies will be necessary, Adler-Abramovich says.

She adds that the newly invented resin-based material is aesthetically pleasing — nobody wants weird-looking teeth — and it’s also nicely rigid, as teeth are supposed to be.

Technically speaking, the Tel Aviv scientists discovered that self-assembling building blocks of Fmoc-pentafluoro-L-phenylalanine has potent antibacterial activity. Now you know. They then incorporated the blocks of the Fmoc into fillings. Adler-Abramovich adds that it should be affordable — and the sky’s the limit. They are also looking at other applications, including wound dressings and tissue scaffolds.

Research for the study was led by Adler-Abramovich and TAU doctoral student Lee Schnaider, in collaboration with Prof. Ehud Gazit, Prof. Rafi Pilo, Prof. Tamar Brosh, Dr. Rachel Sarig and colleagues from TAU’s Maurice and Gabriela Goldschleger School of Dental Medicine and George S. Wise Faculty of Life Sciences.