Advantages of air and electric driven handpieces
The handpiece is one of the most commonly used dental instrument in practice today. With many applications in endodontics, general dentistry, and implantology, having a comfortable handpiece that works well is essential. In many countries the high speed, air-driven turbine is the most popular option, because the system is much cheaper than an electric handpiece and it is easy to service. However, the electrical handpiece is rapidly gaining popularity and is used beside a turbine more frequently in Europe and Asia.
Despite both of these tools being good options, and better than the old belt-driven handpieces, there are advantages of each system. When comparing air-driven to electrical handpieces, two important factors to consider are the speed, expressed as revolutions per minute, and torque, expressed as watts and a measure of the instrument’s power.
What advantages bring electric handpiece for you? Here’s a breakdown on the different options and how to decide on the best type of handpiece for different preparations.
Air Driven Handpieces
Air-driven dental hand pieces operate using air energy to create a cutting or rotary motion. This technology has been around for decades and is well-proven and easy to service. As a result, manufacturers have had the time to improve the dependability and strength of their product and even lower their costs to reduce the price.
In fact, there are several advantages to using an air-driven instrument. Air-driven high speed handpieces, mainly called turbines, are still a bit smaller in head height, lighter in weight, and easier to handle than their electrical counterparts. This translates to improved accessibility, reduced user fatigue and in some cases, a more comfortable user experience, especially in busy offices where the hand piece is used frequently. Many dentists also report that they can feel what they are doing more easily when using an air-driven handpiece, because there is a speed reduction and a change of the frequency, so the dentist “hear” the contact of the bur to the tooth. This results in a more sensitive work process.
Air driven high speed handpieces tend to have a higher speed, but a lower torque, especially as compared to an electrical piece. However, when a bur comes into contact with the tooth, resistance builds up and slows down the bur to 150.000 – 300.000 rpm. The harder the load of the bur is, the slower the bur spins. In the last 10 years, the power of the turbines increased significantly so that the standard turbines have nowadays a power of over 20 Watt, where a load of 3 N to the tooth will be no problem. Under the recommended standard load of max. 2 N the turbine has a higher milling efficiency, due to the higher speed. Only at a very high load, e.g. when preparing crowns, the milling efficiency of the motor driven high speed is higher.
Finally, air-driven high speed handpieces are less likely to become damaged during sterilization procedures, and if they do, repairs are less costly than a high speed motor driven handpiece. The overall investment is much lower – no electronic and no motor is necessary.
There are several disadvantages to using the traditional air-driven low speed handpiece. One major issue is the noise and vibrating sensation of the air motor. Many dentists work very hard to make their office a relaxing and nonstressful experience, especially with the level of anxiety that many patients feel when having dental treatment. However, air-driven low speed handpieces make a distinctive whirring noise that can disrupt the relaxing environment and be jarring to patients.
Many people feel a bit uncertain about starting with an electrical handpiece. Their air-driven instrument works just fine and the cost of upgrading seems too steep. The learning curve may seem intimidating, as it involves not just learning the mechanical act of operating a new tool, but also getting a feel for how it handles.
Electrical handpieces utilize an electric motor to create the rotation and cutting motion of the burs. This creates an instrument that tends to be a little heavier and can increase user fatigue, especially when used for long periods of time. In the hands of an inexperienced practitioner, there may be a slightly higher risk for placing increased pressure on the tooth during cutting, because there is no “sound-feedback” like at an air driven instrument.
Electric high speed handpieces run at max. 200.000 rpm and are a bit slower than their air-driven high speed counterparts. Electric ones provide a consistent torque that does not decrease with resistance and higher load. It also tends to produce a smoother and more precise cutting edge, due to the stable speed.
The big advantage of the motor driven electrical handpieces is the possibility to define a fix and constant speed, and allows a high flexibility in preparations. The constant speed of the electric motor can set between 100 and 40.000 rpm, the speed of an air motor is mainly limited between 5.000 – 20.000 rpm. Some electric systems allows to control the torque at low speed and do additional ENDO preparations.
The head diameter is a little bit smaller, so that the sight angle is better which results in a better sight to the preparation area.
Patients also tend to prefer electric handpieces because they are quieter and don't produce the same vibratory sensation. For patients with dental anxiety, this is a big deal and can help patients stay compliant with their treatment. In addition, patient satisfaction translates to positive reviews online and increased patient retention.
The difference in noise is mainly in the higher frequency of the idle speed of an air-driven high speed turbine and in a higher sound, which is since the introduction of the Silence Technology only 1.5 times higher than at a motor driven high speed. The difference in the low speed section is much higher. The air motor has a significant noise while the electric motor is nearly noiseless.
The slow down time is at the electrical high speed system better, then at a standard turbine. In the last years there were also improvements done, so that the run down time at some special products is about 1.5 times higher than at electrical high speed systems.
Overall electric motor system are nowadays equipped with LED light, which will give you a further advantage.
Making the Decision
Making the decision to start working with an electrical one is not a small one, but it is will allow to get the advantages of two systems.
The cost to start can be considerable, especially when you have several work stations. Therefore it is a good alternative to upgrade an existing unit with a device that can easily get attached to the dental unit – ELECTROmatic with the KL703 LED motor from KaVo. It involves changing workflow and learning a new system.
However, a 2010 study published in the Journal of Prosthetic Dentistry did find that electrical handpieces are more efficient cutters, especially with the metal alloys commonly used in dental procedures. Coupled with widespread popularity of the electrical instruments elsewhere, it may warrant investigating whether it’s a viable option for you and your practice.