The Ultimate Guide to Dental Handpieces
Dental handpieces are an essential part of any dentist’s armoury and used daily for various procedures.
Our guide to dental handpieces aims to provide a detailed breakdown of the different types of handpieces, their primary uses and key functionality to help you make an informed purchasing decision.
What are the different types of dental handpiece?
High speed turbines
High speed turbines are one-piece units, meaning they are an entire system with an inbuilt motor. They can be connected directly onto the appropriate dental unit hose/tubing provided they are compatible.
These handpieces are slightly curved in appearance, with a head that can fit a variety of dental burs. More information on burs can be found in our Ultimate Guide to Dental Burs.
What exactly is a dental turbine and how does it work? Put simply, air pressure from the handpiece’s in-built air turbine is what drives the rotational motion of the bur for cutting or polishing. This is activated by the dentist stepping on the dental foot pedal.
Inside the head of the handpiece are lubricated ball-bearings which hold a friction-grip burr firmly and centrally, allowing the shank of the burr to rotate smoothly along a central axis with minimal friction.
High speed handpieces can reach speeds of up to 450,000 repetitions per minute (rpm).
The two small holes at the top of the handpiece head are where the air and water spray out from. The water coolant feature is used to prevent the tooth from overheating.
What is a high speed dental handpiece used for?
- Removing decay
- Removing old fillings
- Preparing the outline and retention grooves for a new restoration
- Finishing or polishing a new restoration
- Crown or bridge preparation
Low speed handpieces
Unlike single-unit high speed turbines, low speed handpieces are made up of more than one component.
The motor that drives a low-speed handpiece can be either air or electric driven.
Within the handpiece is internal gearings which allow the friction grip burr to rotate at a constant speed independent of torque.
As low speed handpieces are operated at lower rpms and remove tooth structure much slower, they do not require the addition of water spray, however some attachments do include this feature.
Average speeds of a slow speed handpiece range from 10,000 to 40,000rpm. Rotation speed is determined by the motor operating it. Electric motors will typically rotate a bur at around twice the speed of an air motor.
Contra angle handpieces, which are curved in design, are typically used intraorally (inside the mouth). Straight handpieces are used more for extraoral (outside the mouth) procedures.
What is a low speed handpiece used for?
Contra angles handpieces
- Removal of decay
- Finishing or refining of cavity preparation
- Finishing and polishing of restorations
- Adjusting crowns, bridges and dentures
- Trimming and contouring of temporary crowns
- Trimming and relining of removable dentures
- Trimming and contouring of orthodontic appliances
- Used during polishing procedures to hold prophy cups or brushes
- Prophy angles can be stainless steel metal or disposable plastic
Contra angles and straight angles can both be used as electric handpieces when connected to an electric driven motor.
Electric handpieces are typically heavier and more expensive compared to air driven handpieces.
However, they have several advantages and are generally considered superior in most departments, including power, control and torque.
Torque is the overall efficiency and cutting power of the handpiece. Though air driven turbines can reach up to double the speed of an electric handpiece, they lose about 40% of overall speed when cutting begins.
Electric handpieces on the other hand can maintain a constant speed and lose no power during operation.
Torque settings can also be adjusted with electric handpieces to suit various procedures, including endodontic treatment.
As they do not rely on air, speed increasing handpieces with electric motors also produce less aerosol than air turbines which is beneficial for infection control. Find out how here.
Endo handpieces are designed specifically for root canal shaping prior to cleaning and filling. They are built for high precision control and to minimise the chances of file breakage.
Most modern endo handpieces are compatible with all popular NiTi file systems and come in a range of different speeds for either electric or air motors.
Surgical handpieces or implant handpieces
Surgical handpieces are designed specifically for oral and maxillofacial surgery and implantology. They are built to be particularly robust with high quality stainless steel.
These are available as contra angles or straight handpieces, with or without fibre optics.
Gear ratios explained
A handpiece’s gear ratio indicates its speed capabilities and what procedures the handpiece is most suitable to perform.
A gear ratio of 1:5 offers higher speed and can be used for heavier duty procedures, such as cavity preparations and crown cutting.
A handpiece with a 1:1 ratio is low speed and will rotate a bur at a maximum of 40,000rpm (electric) or 20,000rpm (air driven). These handpieces have the same rpm as the motor.
Low speed handpieces are more suitable for lighter jobs such as refining a preparation, removing caries or adjusting ceramics.
Handpieces with a speed decreasing ratio of 4:1 will rotate four times slower than the driving motor.
Gear ratios are easily identifiable by their universal colour code (pictured). A red ring around the handpiece indicates speed increasing, a green ring indicates speed reducing and a blue ring indicates no change in speed.
To ensure your new high speed handpiece is compatible with your current chair tubing, couplings are available for most handpieces on the market, including BA, Bien Air, KaVo, Dentsply, NSK, Roeko and W&H.
The two most common types of handpiece couplers are the “Borden” coupler and the “Midwest” coupler.
Borden couplers have two or three distinctive holes which provide the connection between handpiece and hose. The larger hole is for air intake used to drive the turbine and the small hole is for water.
A Borden connection has no air exhaust and the air blows directly out the handpiece.
The Midwest style can have as little as two holes but usually has four or five. One of the larger holes is used for air entering the handpiece while the other is the air exhaust.
The other holes on a Midwest coupler are for water spray and fibre optics.
New style couplers with 6 pins are also available to connect with handpieces that utilize a six-pin connection.
What else to look out for
This is the ability of the dental bur to spin tightly on its axis. The better the concentricity the less likely the bur is to wobble.
Electric handpieces are considered to have greater concentricity compared to air driven handpieces as the turbine is more likely to experience concentricity-compromising wear and tear.
Emitted from the handpiece head, in-built fibre optic lighting can be used to illuminate the cutting surface and assist with intra-operative vision. Further detail on fibre optics can be found here.
W&H fibre optic handpieces offer “daylight quality light” in some of/all their handpieces which is superior to other manufacturers.
Handpieces are notoriously noisy pieces of equipment and their frequent use can contribute to hearing difficulties among dentists.
To protect against this, handpieces should ideally produce as low a decibel (dB) rating as possible without compromising performance.
Air driven turbines generally produce more noise than electric handpieces.
Patients may find quieter handpieces easier to tolerate, however some dentists use the sound created by the handpiece as a guide, so it’s important to weigh up these factors
Handpiece head size has a big impact on visibility for the dentist. Mini head sizes (9.8 x 8.5mm) are preferred for posterior procedures which require a greater deal of visibility and access.
Large heads (14.5 x 13mm) produce more torque and cutting power which speeds up procedures.
Standard sized head sizes (11.9 x 10.2mm) are considered a middle ground that can offer the partial strengths of both with no glaring weakness.
One of the most basic decisions a dentist must make when choosing a handpiece is what type of chucking mechanism to use (i.e. how is the bur retained and changed?)
Autochucks are by far the more popular choice as they do not require the use of any other tools to open or close the chuck. Located on the back of the handpiece head, autochucks can release a bur or lock it into place using either a push-button or lever system.
Manual chucks are considered somewhat outdated and involve the use of a small wrench to secure and loosen the bur.
Handpieces may have either ceramic or stainless steel bearings in their turbines. Ceramic bearings are considered more durable than steel.
Whatever material is used, it is crucial to keep bearings in the best condition by cleaning and lubricating them often in accordance with the manufacturer’s instructions.
Handpieces have come on leaps and bounds in recent years in terms of how they feel in a dentist’s hands.
The lighter the handpiece, the more comfortable it should feel to use. Modern handpieces are designed to be lightweight and perfectly balanced - ideal for using for extended periods of time without causing strain.
Leading handpiece manufacturers include BA International, W&H and NSK.
Ensure you always buy your handpieces from a reputable dental supplier such as Kent Express. Don’t be tempted to buy cheap copies online, for example from well-known auction websites – you have no idea where the product is manufactured, quality is often an issue, and cheap copy handpieces often do not meet European safety standards.
Ensure your handpiece holds the CE mark and look for manufacturer guarantees. Ensure the manufacturer can offer technical support post-purchase if required.
The country of manufacture is also important: Germany, Austria, Switzerland and Japan are known to produce excellent quality handpieces.
Most handpieces are now suitable for washer disinfectors and autoclaves and will last several years if manufacturer maintenance guidelines are followed.
Innovative reprocessing devices such as the W&H Assistina TWIN (pictured) are designed to make maintaining handpieces quicker and easier.
If you’re wondering how do you oil a handpiece or at what stage to do it, follow our brief 8-step manual maintenance guide below.
- 1 - Remove any inserted rotary instrument from head and disconnect handpiece from coupling or motor. Wipe external surface with a paper towel or tissue.
- 2 - Rinse the external body of the instrument under procedural water and clean with a brush for approximately 20 seconds.
- 3 - Wipe down the external body of the handpiece with an appropriate disinfection wipe.
- 4 - Check manufacturer guidelines to see if handpiece is suitable for washer disinfector (not all are). If so, proceed following manufacturer instructions.
- 5 - Holding the can upright, insert lubrication nozzle into the connection end of the handpiece and spray for roughly 2 seconds. Do the same for the chuck at the head of the handpiece. Always use a trusted lubrication solution, such as BA Ultimate Oil, W&H Handpiece Oil (MD-400) or NSK Pana Spray.
- 6 - Run handpiece until the fluid is clear of debris or excessive oil. Check this using a tissue or paper towel.
- 7 - Bag handpiece in an appropriately sized sterilization pouch.
- 8 - Sterilize handpiece in an autoclave according to the manufacturer guidelines and dry completely once finished.
However well you maintain your dental handpiece, there’s bound to come a time when it needs repairing. Always consider repairing your handpiece first before purchasing a brand new one.
Signs that your handpiece may need repairing include if it is emitting excessive vibrations, if it is not rotating as fast as it should or it’s making unusual noises.
If these issues occur, it is worth having your handpiece checked over as the inner mechanisms might need a professional repair.
Visit our Handpiece and Equipment repairs page for more information.
For additional help finding the right dental handpiece, motor, coupling or maintenance kit, speak to Jack our handpiece specialist on 01634 878759.