What is it?

Dental handpiece is a dental instrument, either air driven or electrically driven, that holds various disks, cups, or burs, used to prepare a tooth to receive a restoration or to contour, clean, or polish a tooth or restoration. "Handpiece" and "engine" are more generic and euphemistic terms for generic dental tools.

What is it used for?

Usually to remove decay and shape tooth structure prior to the insertion of a filling or crown.