Forget what you've been told since childhood about the permanence of your adult teeth. New research is raising hopes that beams from low-power lasers could one day prompt your damaged teeth to regrow.
Targeted light is already a commonly used therapy. It can be used to kill tumor cells, reduce pain and inflammation, and promote wound healing. It can even help regenerate damaged mammalian hearts, skin, lungs, and nerves. Photobiomodulation, as such healing procedures are called, is thought to work by acting on stem cells.
Some dentists already use lasers to remove decayed parts of teeth. And new findings, described last week in Science Translational Medicine, suggest that less powerful dental laser treatments could one day activate dental stem cells, helping your teeth recover following a dentist visit.
"The field of light therapy has been around since the '60s, but it has been plagued by inefficacy, because very low doses do not have any effect while higher doses are detrimental."
Researchers bored holes in the molars of poor lab rats, then stuffed the wounds with fillings. One of the cavity-like wounds in each rat was fired at with a low-powered laser; the other was left alone and monitored as a control. Within 12 weeks, the scientists discovered that the laser-treated wounds were growing dentin—the protective layer of tooth that sits between the pulp and the enamel.
The treatments were far from perfect. Instead of nice dentin bridges, pulp stones formed. But the researchers think the bridge could be mastered by tweaking the laser's focus, which would be an easier task when using larger animals. I.e., us.
The scientists performed lab tube-style experiments using tooth tissue harvested from humans and other animals to conclude that such light treatments activate a growth factor complex that's called transforming growth factor–β1. TGF-β1, as the complex is handily known, was already known to help trigger stem cells into regenerating healthy tissue.
The results raise hopes that the shiver-inducing whinny of dentists' drills could one day be abandoned for the gentler pulse of laser-fired lights, with improved treatment results. Such treatments would require "different types of lasers," says National Institutes of Health investigator and author Praveen R Arany, "used with different protocols but with the same purpose"—to restore and regenerate tooth structure.
So when might a trip to the dentist result in the Wolverine-like recovery of our pearly whites? Arany believes the therapy is "well poised for clinical translation," particularly since such laser devices are already in use. He also notes that the regulatory barriers for their approval are lower than is the case for drugs.
But he's not ready to say when your dentist could start swapping out drills for lasers sets.
"The field of light therapy has been around since the '60s, but it has been plagued by inefficacy, because very low doses do not have any effect while higher doses are detrimental," Arany says. "While this work outlines one precise molecular mechanism in a given context, the precise therapeutic window needs to be carefully worked out. Safety must be established before light therapy can become mainstream standard of care."