The bones around mouse teeth like this one were rejuvenated by anti-ageing drugs STEVE GSCHMEISSNER / SCIENCE PHOTO LIBRARY

A transplant drug with anti‑ageing properties has been shown to rejuvenate the oral health of old mice. The drug, called rapamycin, regenerated the bone in which teeth are embedded, restored the mouth microbiome to a youthful state and reduced inflammation.

It is the first time any treatment has been shown to rejuvenate oral health, says team leader Matt Kaeberlein at the University of Washington in Seattle. “We could actually see spots where new bone was growing around the teeth.”

Two-thirds …