Scientists may have found a better way for your dentist to look for cavities. It involves passing an electric current through a tooth and all the way down your arm.

Don’t worry, it won’t hurt.

In fact, by detecting the earliest stages of decay, the technique could spare you the hassle of drilling and fillings, says researcher Christopher Longbottom.

It hasn’t been tried on patients yet, but it was 100 percent accurate in detecting decay in 26 extracted teeth, Longbottom and colleagues reported in the February issue of the journal Nature Medicine.

The goal of the technique is to detect tiny pores inside the tooth that are created by the very earliest stages of decay. A dentist can then take steps like applying fluoride or a sealant.

The device detects pores by passing a current through the tooth and comparing the input frequency with the output frequency.

To use the device on patients, a dentist would slip an electrode between teeth or put it on the biting surfaces. The tiny current would go into the tooth and down the arm to an electrode in the hand, then back to the device.