Narrator: This is Science Today. Dentists can reduce radiation exposure from x-rays by using what's called rectangular collimation. UCLA School of Dentistry professor, Stuart White says it's an instrument patients can easily recognize.

White: The dental assistant will line up the x-ray beam right against this little device outside your mouth and then the x-rays can only come through the little rectangular hole in the face shield of this device holding this film. So, one way or another, you the patient will see a rectangle, in the shape of the tube pointing at you or in the device holding the film in your mouth.

Narrator: White says many dentists are also using digital x-rays, which feature a sensor device the size of a postage stamp.

Taylor: It goes in the patient's mouth and it uses about one quarter of the exposure of conventional film and so many dentists are moving towards digital imaging. You'll see a computer monitor and a picture of your teeth will appear right away.

Narrator: For Science Today, I'm Larissa Branin.