It’s hard to imagine dentistry without the ubiquitous “drill,” whose high-pitched whine has the reputation of making patients squirm. And these days, there are more choices than ever in dental handpieces. But for removal of decayed tooth structure or old restorations, crown preps, finishing and polishing, or even tackling endodontic work, it’s tough to beat a high-speed handpiece.
High-speed dental handpieces are either air-driven or electrically powered. Although electric units have long been popular in Europe, more economical air-driven handpieces are more traditional among American clinicians. But that appears to be changing as more practitioners in the U.S. experience the benefits of going electric. 1Choi C, Driscoll CF, Romberg E. Comparison of cutting efficiencies between electric and air-turbine dental handpieces. J Prosthet Dent. 2010;103:101–107.
Speed vs. Torque Dental Handpieces
Reaching speeds as high as 420,000 rpm, high-speed air-turbine dental handpieces may outrun electrics, which generally top out at 200,000 rpm, but they lack the torque of the latter, and have been known to stall under load. In fact, their speed may drop as much as 40% or more once their burs hit a surface.2Kurtzman G. Electric handpieces: an overview of current technology. Available at: http://www.endoexperience.com/documents/ElectricHandpieceSummary-Kurtzman2007.pdf Accessed November 13, 2018.
Most air-driven dental handpieces only deliver up to 30 watts of power while electric units offer up to 60 watts, which can cut through the toughest jobs nonstop. In fact, they have been found to surpass air-turbine handpieces in cutting efficiency when tested on a variety of materials, including machinable glass ceramic and amalgam.3Choi C, Driscoll CF, Romberg E. Comparison of cutting efficiencies between electric and air-turbine dental handpieces. J Prosthet Dent. 2010;103:101–107.
Air-driven handpieces are lighter and more compact than the electric handpieces. But electrics are much quieter, and, thanks to that higher torque, they are said to inflict less upper-body fatigue and generate less heat.4 Kurtzman G. Handpieces: the drill on high speeds. Available at: http://www.endoexperience.com/filecabinet/Endo%20Related%20Restorative%20Dentistry/handpeice%20comparison%20kurtzman%20product%20advances%2010-05.pdf. Accessed November 13, 2018.
Nonetheless, because high-speed handpieces can generate enough heat to damage pulp, they are furnished with integrated cooling systems.5 Kurtzman G. Handpieces: the drill on high speeds. Available at: http://www.endoexperience.com/filecabinet/Endo%20Related%20Restorative%20Dentistry/handpeice%20comparison%20kurtzman%20product%20advances%2010-05.pdf. Accessed November 13, 2018. This comes in the form of a spray or cooling mist, emitted from air/water ports.
All that spraying, however, may make patients feel they are about to drown, and also increase the risk they will swallow debris. A comprehensive isolation system can be a clinician’s best friend in these situations. Isolite, for instance, offers a soft, flexible mouthpiece, which cordons off the field of operation, catching any errant materials, while it protects adjacent tooth structure and retracts oral tissues. Meanwhile, its suction feature offers continuous evacuation. In addition, the Isolite 3 also provides illumination, further upping the odds for restoration success.
Cleaning, Maintenance and Sterilization Protocols
But to ensure success, high-speed dental handpieces require regular maintenance, including cleaning, lubrication and sterilization between patients. In fact, according to guidelines published by the U.S. Centers for Disease Control and Prevention (CDC) all handpieces that can be removed from air and waterlines must be cleaned and heat sterilized.
But following a recent request from the American Dental Association (ADA) for clarification regarding cordless devices, or those not attached to air or waterlines, the CDC now advises dental practitioners to follow current U.S. Food and Drug Administration (FDA) policies, using FDA-approved handpieces and following validated manufacturer’s reprocessing instructions, even when that doesn’t include heat sterilization.6Burger D. ADA, CDC work together to clarify handpiece infection control recommendations. Available at: https://www.ada.org/en/publications/ada-news/2018-archive/february/ada-persuades-cdc-to-revise-handpiece-infection-control-recommendations. Accessed November 13, 2018.
More information is available at: https://www.cdc.gov/oralhealth/infectioncontrol/index.html.
High-speed dental handpieces are among the bread and butter technologies of modern dentistry. And innovations are ongoing — including designs featuring the smallest heads possible for visual enhancement, 360-degree swivel capability to help cut down on hand fatigue, and mechanisms that keep burs secure while also expediting bur changing. Many of those who have switched to electric units have never looked back. And as price tags for these handpieces drop, more dentists in the U.S. may find their enhanced precision, efficiency and patient-pleasing abilities irresistible.