A handpiece is the name dentists call their dental drill. An electric handpiece is really a hybrid between a conventional air driven handpiece and an all electric powered driven handpiece with which you may be familiar. One aspect of dental procedures that patients particularly do not like is the pulsating high pitched sound of the dental drill. An air driven handpiece will rotate a burr (dental drill bit) at approxiamtely 40,000 rpm. When the burr touches the tooth, the resulting friction will cause the drill to stall slightly. As the dentist moves the burr around the tooth to prepare it for a restoration, the burr is removed from the surface of the tooth allowing the air pressure to build up and the burr to return to its original speed of 40,000 rpm. The result is a high then low then high then low pitch sound. Other than the bothersome character of the sound, the varying speeds result in inconsistent forces on the tooth creating “hot spots” which may damage the fragile nerve at the center the tooth.
Electric handpieces also use compressed air to rotate the burr at 40,000 rpm but have a supplementary electric motor to keep the burr spinning at high speed. Since the electric motor also contributes to the torque of the burr, not as much air pressure is required to get and to keep the burr rotating at a constant high speed. Maintaining the high speed of the burr reduces friction between the burr and tooth surface as the tooth structure is cut rather than ground away. The result is a quiet, precise and efficient tooth preparation with a minimal negative effect on the dental nerve. The more precisely a tooth can be prepared, the better the fit of your new restoration (crown, veneer, or filling). As an added bonus, tooth preparation time is much quicker.