When a dentist says the word "cavity" a lot of people sweat thinking about painful injections and relentless drilling. But scientists in Britain have developed a new procedure dubbed EAER, or "Electrically Assisted Enhanced Remineralisation," that can repair a slightly decayed tooth before a deep cavity forms. The supposedly painless procedure involves cleaning (not drilling) the tooth of any signs of mild decay, then flushing it with minerals and stimulating it with an electric pulse. This pushes the minerals into the deepest part of the lesion and speeds up a naturally occurring process called "remineralization". This is where minerals in your saliva and some foods enter the tooth enamel and make it stronger.