When it comes to buying dental handpieces, you want each practitioner at your practice to have the tools they need to perform at their best so your patients get the best possible outcome.
Understanding the anatomy of a dental handpiece will help you better understand what you’re looking for in a handpiece. To that end, the following article discusses in detail about the various parts and components of a dental handpiece, as well as how they each serve their purpose.
1. Dental Handpiece Body
The body, neck, and head form the largest and most important part of a dental handpiece. Cheap, less durable handpieces usually have a body made of an inexpensive metal such as brass. Stainless steel is a lighter and more durable body option than brass, offering greater protection against damage caused by autoclaving. Titanium is even lighter than stainless steel, but titanium is also more expensive; stainless steel offers the same functionality at a lower cost.
The body delivers air and water to the handpiece head, which includes:
- Drive air (which rotates the turbine)
- Coolant water
- Chip air (this atomizes water spray)
After passing through the turbine, drive air is exhausted through the handpiece’s hollow body and down the tubing.
New sterilizer designs stave off internal corrosive buildup that closes off the handpiece exhaust ports by applying fresh distilled water for every steam cycle.
Some models come with multi-port water spray that evenly distributes water throughout the work area.
2. Dental Handpiece Turbine
Handpiece turbines operate at free and active speeds.
The maximum rpm with no load is classified as free speed. Conversely, the active speed is the rpm to which the turbine decreases during engagement with the tooth.
Often, a high-speed handpiece’s active speed is between 300,000 and 450,000 RPM, allowing for streamlined teeth cutting. It also leaves a clean, smoothed-out margin that mitigates trauma to the impacted tissues and structures. Slow speed handpieces run between 5,000 and 40,000 RPM.
The torque and power measure a handpiece’s ability to remove tooth structure. Power is measured in watts of energy, while torque is expressed in oz/inch.
Older generation handpieces could only generate 10 to 13 watts of power, paling when compared to their newer counterparts' 15 to 18 watts. Another potential advantage of new models is smaller head sizes.
With more power comes less physical demand as a practitioner, reducing strain and fatigue on your hands and wrist. This perk provides long-term ergonomic benefits that extend practitioners’ careers.
3. Dental Handpiece Bur
Burs are fixed or interchangeable tools attached to the handpiece that are used for cutting, grinding, and removing hard and soft tissue in the oral cavity. Dental burs are typically made from tungsten carbide or diamond. The component that securely holds the bur for polishing or cutting is called the chuck.
Turbine life can be impacted by the cutting instrument or bur. Overusing dull burs can cause you to place more lateral force against the tooth structure. As a result, the side load on bearings increases, generating too much friction during handpiece operation.
4. High Speed Handpiece Coupler
A coupler connects a high speed handpiece to its tubing. Couplers have been standardized by the International Organization for Standardization (ISO) based on the dimensions and placement of the coupler’s holes and exhaust ports.
Sable Industries offers two fiber optic high speed handpiece models that fit onto Kavo MultiFLEX couplers and two non-optical high speed handpiece models that fit onto Sable 4-hole couplers. Sable model Kavo MultiFLEX couplers (4, 5 & 6 hole), NSK style couplers (4 & 6 hole), and Sable couplers for our non-optic high speeds (2 & 4 hole). All 6 hole couplers come in both LED or Halogen bulb variations (Kavo and NSK styles).
Anatomy of a Handpiece and its Impact on the Buying Process
Head Size and Angle
Head size and cutting power typically contrast, leading to a natural balancing act between the two.
Smaller head sizes contribute to enhanced access and visibility in the posterior region.
Alternatively, larger head sizes utilize a bigger turbine impeller with greater inertial mass levels. This feature leads to increased power output. With more power comes less time spent on tooth preparation.
You also must weigh head angulation.
Typically, handpiece heads have been angled 22.5 degrees backward to keep the instrument in a practitioner’s line of sight. The pitfall here is limited access to posterior teeth. The handpiece will contact the maxillary arch, too, causing patient discomfort.
However, the head angles on newer designs improve access to posterior teeth while providing increased patient comfort.
Long-term hearing loss is a real and present risk for dental professionals using high-speed handpieces throughout their careers.
Beyond that, when handpieces are too loud, it’s detrimental to your bedside manner, causing discomfort for patients and triggering their anxiety.
Newer handpiece models operate with reduced sound levels, operating anywhere between 58 and 71 decibels.
Ergonomic Body Design
Carpal tunnel syndrome and other related musculoskeletal diseases can result from holding awkward, heavy handpieces for extended periods.
Fortunately, handpieces are constructed with drastically different lengths, weights, and balances, meaning models exist for practitioners of all sizes. Find the best feel and fit for your hand by “test-driving” ergonomic handpieces at your practice. Don’t demo a handpiece at a tradeshow because it can’t adequately emulate your work environment.
Wider, flared body shapes at the handpiece’s rear are currently trending. This design offsets the need for pinching force when gripping the instrument, limiting wrist and hand fatigue.
Water spray–used as a coolant–is a feature found in all high-speed handpieces.
The cutting-edge technology these days is a multiport spray from the face of the handpiece. This innovation results in evenly distributed coolant water across the tooth’s surface. It also prevents any blocking of water spray during cutting on the distal tooth surface.
Fiber optics dictate your visibility when using a handpiece.
Cellular optics are now being used in handpiece construction. Instead of being made from a collection of optic fibers, cellular optics are made of one solid glass rod.
LED light bulbs are the latest innovation in fiber optics, generating a whiter, brighter light.
Fully rotating swivels can be added to connect delivery tubing to the handpiece. This feature decreases tubing torque, preventing long-term wear and tear.