The end of dental fillings?

Scientists say they have invented a special gel that will allow dentists to repair decaying teeth without the need for fillings, reports TheGuardian.com. The enamel that coats our teeth is the hardest tissue in the human body, but this complex material can’t repair itself when damaged. Dentists use many different materials to fill cavities—including resin, metal alloys, amalgam, and ceramics— but none sticks perfectly to enamel and so they often come loose. To crack this problem, researchers in China used a gel containing calcium and phosphate—enamel’s building blocks—to encourage teeth to self-repair. In trials, the gel was applied to human teeth that were then placed in a fluid that mimics conditions inside the mouth. Within 48 hours, the gel had created a 2.7-micrometer layer of a substance matching the structure, strength, and wear-resistance of natural enamel. While that’s only a tiny fraction of the depth needed to tackle cavities, the process could be repeated to build up the repair layer. “After intensive discussion with dentists,” says co-author Zhaoming Liu, from Zhejiang University, “we believe this new method can be widely used in future.” a potentially habitable planet outside our solar system. Exoplanet K2-18b is about eight times the mass of Earth and orbits a red dwarf star in the Leo constellation, some 110 light-years from our planet.

Using data collected by the Hubble Space Telescope on how starlight passes through the exoplanet’s atmosphere, researchers found clear signs of water vapor, along with hydrogen and helium. The discovery is important because K2-18b sits in its star’s so-called habitable zone and has the right temperature for liquid water to exist on the planet’s surface. “Finding water in a potentially habitable world other than Earth is incredibly exciting,” study author Angelos Tsiaras, from University College London, tells CNN.com. “It brings us closer to answering the fundamental question: Is the Earth unique?” The exoplanet is too distant to explore by probe. But the next generation of space telescopes, set to launch in the 2020s, might be able to identify gases in the exoplanet’s atmosphere that could be produced only by living organisms.

were 48 percent less likely to suffer a heart attack, stroke, or heart failure than those who never snooze in the daytime. Napping longer or more often didn’t deliver any additional health benefits. The study was only observational and so couldn’t prove cause and effect, and the researchers say it’s still unclear exactly how napping might influence heart health. “Our best guess,” lead author Nadine Häusler tells NBCNews.com, “is that a daytime nap just releases stress from insufficient sleep.”