Teeth don't grow back, as your dentist might like to remind you while revving up the drill for a root canal. But scientists have now found a way to regenerate dentin, the hard stuff in the middle of the tooth, right in the mouth. It's surprisingly simple too — all it takes is a blast of laser.
In a study published today in Science Translational Medicine, a Harvard-led team lays out how a low-power laser can trigger stem cells in the tooth to form dentin. Currently, damaged dentin is replaced with synthetic material, like when you get a filling or a root canal.
The current study builds on years of anecdotal reports about low-power laser stimulating skin or hair growth. (Yes, at the same time high-power lasers do the opposite.) Something about laser light stimulates certain biological pathways in cells. Scientists have now figured what that something is when it comes to dentin. A blast of laser induces reactive oxygen species, which are chemically active molecules that then activate a growth factor to stimulate dentin growth.
Although studies have regenerated parts of a tooth from stem cells in a petri dish before, the laser procedure can happen right in the month. This study's authors got it to work in tiny rodent teeth, and now they're continuing onto human clinical trials in hope it could someday replace some current dental procedures. I don't know if the thought of even low-power lasers makes the dentist less terrifying, but I'd take it over a root canal. [Science Translational Medicine]
Picture: scaffold seeded with stem cells differentiating into cells that form dentin. This is a false colour scanning electron microscope image. Arany PR et al.