Don't care for the dentist's drill? It may not be long before your dentist puts away the drill. A tooth develops decay when minerals leach out through a microscopic defect, undermining the enamel and possibly leading to a physical cavity. At the moment dentists drill out the decay and fill the tooth with amalgam or composite resin. The new technique uses a tiny

to speed up the re-entry of calcium and phosphate minerals into the tooth to repair a defect — that's the way nature would do it, but more slowly. The technique doesn't need a drill or an injection and the tiny electric current can't even be felt by the patient. And presumably your face isn't numb for hours afterwards either.

GOAL: In 2014 the World Cup football matches should include some very clear decisions about whether or not the ball has crossed the goal line. In the stadium 14 high-speed cameras operating at up to 500 frames a second capture the position of the ball in 3D. Each goal has 7 cameras trained on it at all times: two at the halfway line, two more between halfway and the goal line and another camera behind the goal. A fibre-optic cable carries live data from the cameras to an image processing computer that monitors the movements of every object on the pitch, filtering out players and the referee. The ref wears a watch that vibrates when the ball crosses the goal line. The GoalControl-4D system should make the ref's job a great deal easier and make it harder for fans and players to argue with the decisions.


OPEN AND SHUT: In a hurry at the supermarket? Had to wait while the automatic doors get around to recognising that you want to pass through? You're not alone. Now researchers have worked out how to make such automatic doors a lot smarter. Their solution comes in the form of a 3D time-of-flight laser scanner to feed data to algorithms that can detect people, track their motion, and make educated guesses about whether or not they're aiming for the door. The sensor is designed to function in direct sunlight, total darkness and points in between. The software estimates when you'll arrive at the door, and times things so that the door will have just finished opening as you get there. Parents of toddlers beware.

EASY AS ONE TWO: When people are prescribed opioids it can be too easy to accidentally overdose, especially if they're using other prescription medicines too. In case of an overdose an injection of naloxone hydrochloride can save their life. But such injections are tricky to administer and probably require a trip to a medical centre or hospital. Evzio is a handheld device that can be prescribed alongside the opioid and that anyone can use to deliver the lifesaving injection, following either written or verbal instructions. A user removes a safety guard then presses the gadget against the thigh for 5 seconds. The Evzio delivers the injection and also advises calling for qualified medical help. Almost anyone should be able to remove a safety guard and press.

KNOCK, KNOCK: Tap, tap, tap: using your smartphone means lots of tapping, pinching and swiping with a fingertip to get things done. Qeexo's FingerSense technology though may change that, as it can tell the difference between a fingertip, a knuckle, a fingernail, and a stylus. That means you could set up one action to be triggered by a fingertip, say typing text, and another to work when you tap with your knuckle, for example selecting and copying text. The system uses the device's accelerometer to to pick up on the vibration patterns different parts of the hand produce when they come in contact with a touchscreen. That would have interesting possibilities for passwords too.

Miraz Jordan,