Have you had your daily dose of nanoparticles? Millions of Japanese citizens get theirs in the form of toothpaste--toothpaste that not only protects teeth, but actually repairs them. According to a report at Nanowerk:

Scientists have learned to synthesize hydroxyapatite, a key component of tooth enamel, as nanosized crystals. When nano-hydroxyapatite is used in toothpaste, it forms a protective film on tooth enamel, and even restores the surface in damaged areas.

Japan's Sangi Company, Ltd., has sold more than 50 million tubes. Availability of similar products that claim to actually repair cavities is just around the corner. (photo Sangi Company)