July 1, 2014
by Gary Radz, DDS
Manual and pedal handpieces of various types have existed for centuries. The 1940s development of low-speed electric belt-driven handpieces generated significantly increased dental treatment efficiency and accuracy.1 In the late 1950s, high-speed dental handpieces quickly replaced belt-driven handpieces, and revolutionized cavity preparation and dental procedures.1 The high–speed air turbine handpiece has been the primary instrument for most dental cutting procedures over the past 50 years.2 As advances continue, high-speed handpieces remain the ideal dental preparation tool in the foreseeable future.1
Further developments in recent decades have improved handpiece efficiency, comfort, and accuracy. Smaller handpiece head sizes improve patient and operator comfort. Smaller head sizes facilitate handpiece maneuverability in tighter spaces, with less patient jaw fatigue and greater operative area visibility. Technological progress has provided in-handpieces fiberoptic illumination that brightens the preparation field from less than one centimeter away, vastly improving visibility.
Handpieces constitute an essential part of dental practice equipment, integral tools for many treatments that clinicians and dental team members perform.3 Since handpieces are used so frequently, their efficiency and accuracy can greatly affect practice overhead. Outdated, worn, or malfunctioning handpieces are not only inconvenient, but can negatively affect production, efficiency, and procedure accuracy. Although today’s handpieces differ significantly from those of 20 years ago, the latest developments in design and features provide clinicians and dental professionals with efficient, easy-to-use, and precise tools for use in a variety of situations.
Several types of handpieces are available today. With adequate torque, air-driven handpieces impel burs rapidly to efficiently remove enamel, dentin, and filling materials as well as effectively polish restorations. Manufactured with a wide range of innovative design features, air turbine handpieces are suitable for a variety of clinical procedures.2 A very convenient option is the swivel attachments that allow the handpiece to freely rotate on the hose, increasing operator hand and arm comfort, and decreasing fatigue at the end of the day. Fiberoptic handpieces improve visual access, reduce operator stress and optical fatigue, and frequently result in better dentistry for the patient.
One recent study, evaluating six different handpiece models, determined that all could be expected to last through approximately 500 clinical uses/sterilizations, the equivalent of approximately one year of clinical use.4 Since the average handpiece functions effectively for only one year before refurbishing or replacement, it is important for clinician to determine which handpieces can better withstand repeated heat sterilization without an operative performance loss.4 The selection of an appropriate handpiece with acceptable longevity is essential to operator and patient comfort, productivity, accuracy, and proper treatment.
HANDPIECE PURCHASE CONSIDERATIONS
Handpieces come in many brands, with differing characteristics from multiple manufacturers. They may be indicated for universal or specific use. Low-speed handpieces are typically used intra-orally for removing soft decay, cavity preparation, and polishing and finishing restorations. Extra-orally, low-speed handpieces trim, contour, and polish temporary crowns, removable partials, dentures, and orthodontic appliances. High-speed handpieces are used for decay removal, crown preparation, removal of old/faulty restorations, preparation of the outline and retention grooves for new restorations, and finishing and polishing restorations. Additional handpiece categories include ultrasonic, laser, and air-abrasion.
Six key considerations encompass the most important factors for determining the ideal handpiece for purchase. Handpiece torque power represents the rate of doing work, or how long it takes the handpiece to remove a set amount of tooth material. Bur rotation concentricity ascertains the precision manufacturing of the bur head. The noise volume of the handpiece during operation is important for patient comfort (and incidentally, for avoiding hearing damage to the practitioner). Warranty length is an excellent indication of the manufacturer’s confidence in the product. The inevitable turbine repair cost (likely to be incurred soon after the warranty period, and every six months thereafter) must also contribute to purchase decision-making. Last, but not least, the initial cost represents the investment that the practice must make in each handpiece.
There are numerous handpieces available from Kavo, W&H, WOlf, Star and many excellent manufacturers. The author has been using the WOlf Black Label high speed from Dental Savings Club (Montréal, Québec). I find that it offers superior quality and optimal ergonomics. It has maximum cutting power and a very quiet working motor. Its very high manufacturing standard provides a very tight bur concentricity that enables precision preparation with either the medium or the mini head size. Ideal for crown preparations, the handpiece demonstrates excellent cutting ability while offering improved efficiency, durability, and affordability.
The WOlf Black Label provides 21 watts of torque power, for maximum cutting power. With a bur concentricity of 0.02mm, the WOlf Black Label is extremely precise and accurate. The handpiece contributes to a quiet working environment, producing only 60 decibels of sound while in use. Unlike most handpieces on the market, WOlf Black Label handpieces offer a two-year warranty at a very competitively low price (the typical price for handpiece repair). Furthermore, any future turbine repairs are extremely affordable.
An old PFM crown (Fig. 1) with recurrent decay is to be replaced with a new zirconium crown (LumiZir, DenMat). WOlf Black Label’s excellent torque allows a rapid cut through the metal substructure and removal of the old crown. A coarse-grit Kut diamond bur creates the new margin in a single circular pass. The Wolf’s excellent illumination provides superlative visualization of the preparation field.
A new eMax (Ivoclar) crown is to be placed on a lower first molar (Fig. 2). The WOlf Black Label’s precision concentricity allows for the development of an ideally smooth margin.
Minimal preparation porcelain veneers require a careful tactile touch to allow for the required minimal reduction as well as a precision-placed gingival margin. The textured casing of the WOlf Black Label handpiece offers the dentist improved proprioception and an excellent grip on the handpiece as it cuts (Fig. 3).
A fine grit diamond makes minor occlusal adjustments on a newly placed crown (Fig. 4). The ability to adjust to the needed RPM’s and its low noise level help to make the Wolf Black Label handpiece the workhorse of any operatory.
Handpieces provide dental professionals with a universal and necessary tool to complete accurate and efficient treatment. The development of high-speed handpieces increased functionality, precision, and ergonomics, benefiting patients and operators. When selecting an appropriate handpiece for a dental practice, ideal torque power, bur concentricity, noise, warranty length, price, and price of repair all contribute to selecting the right tool. Although a variety of handpieces are available, the WOlf Black Label represents an ideal tool for cost-effective, efficient, and precise dentistry. OH
Dr. Gary M Radz maintains a private practice in Denver, CO. He is on faculty at the University of Colorado School of Dental Medicine. Dr. Radz lectures internationally on esthetic dentistry and dental sleep medicine, and has published hundreds of articles related to these subjects. He is an active member of the American Academy of Cosmetic Dentistry and the Canadian Academy of Esthetic Dentistry as well as having served as the director of Sleep Studies at the Rocky Mountain Dental Institute.
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1. Schulein TM. The era of high speed development in dentistry. J Hist Dent. 2002;50(3):131-7.
2. Dyson JE, Darvell BW. The development of the dental high-speed air turbine handpiece. Part 1. Aust Dent J. 1993;38(1):49-58.
3. Norkiewicz DS, Sundberg MA, Druckman RF, et al. Maintenance and repair of high-speed dental handpieces. Gen Dent. 2001;49(6):636-41.
4. Leonard DL, Charlton DG. Performance of high-speed dental handpieces subjected to simulated clinical use and sterilization. J Am Dent Assoc. 1999;130(9):1301-11.