英伦广角 激光可帮助啮齿类动物受损的牙齿再次生长（在线收听）

Ouch! About a quarter of all school-age kids will break or otherwise damage a tooth. Adults have their share of cracked chompers too.

But what if fixing a busted bicuspid was as easy as zapping it with a laser? Preliminary work with young rats has moved dentistry a small step in that direction. A new study finds that shining a low-power laser on damaged rat teeth activates molecular growth factors already present in the tissue. These growth factors cue stem cells to generate dentin, the bone-like substance that teeth are mostly made of.

Researchers also found that when mice were missing those growth factors, or when the factors were blocked from working, the stem cells would not regenerate dentin when exposed to laser light. That finding confirms the important role these signaling pathways play in dental development. The study, led by David Mooney at Harvard’s Wyss Institute, is in the journal Science Translational Medicine. [Praveen R. Arany et al, Photoactivation of Endogenous Latent Transforming Growth Factor–β1 Directs Dental Stem Cell Differentiation for Regeneration]

Could a light-based treatment for cavities and chipped teeth eventually be in the offing for people? The researchers plan to investigate that possibility for human teeth, both baby and adult. But until then, chew carefully. And don’t lead with your chin.