Dental Electric Motors| The 2021 ultimate purchasing guide

Electric motors reach an idle speed of up to 40,000rpm. This corresponds to a bur speed of 200,000rpm for 1:5 contra-angle handpieces. The maximum power is over 60 W and delivers a constant torque of approx.3 Ncm². This means that electrically powered contra-angle handpieces are not slowed or stopped when the bur cuts through different tooth structures or prosthetic materials. They continue cutting at a virtually constant speed regardless of the load. Compared to high-speed handpieces, burs are much more stable with contra-angle handpieces. Burs in a contra-angle handpiece vibrate much less than with turbines. Improved stabilization means greater precision, faster work, and less heating of the tooth substance during preparation.

It is at this point obvious that dental electric motors are not only easier to install but are also more efficient in use. They make work in dental practice faster and easier. The bigger cost of an electrical handpiece pays back in working speed, efficiency, less tooth heating, improved precision, and greater cutting power.

The currently available range of straight and contra-angle handpieces includes the right instrument for every requirement. Most manufacturers offer products suitable for a wide range of applications and also products for highly specialized clinical applications. See Wikipedia`s  definition for high-speed handpieces

Contra-angle handpieces are available in various ratios, like

increasing contra-angle or 1:1 contra-angle.

Dental electric motors vs air-driven

The advantages of a high-speed handpiece are its simple and robust structure, the lower purchase price, and also the lighter weight. However, over the years the detrimental effect on the operator’s hearing due to the high-frequency sounds emitted by the turbine has become a significant problem. Electric handpieces, in contrast, are quieter and cause less hearing damage than turbines. When the quantity of tooth substance removed per unit of time is considered, it is clear that electric motors with water cooling are superior to the high-speed handpiece for grinding.

With the continuing development of motors in recent years, manufacturers have clearly acknowledged that the ergonomics of the weight and size of dental handpieces play a decisive role in purchasing decisions. The most recent production of dental electric motors adopts Titanium, due to the extremely lightweight that handpieces and contra-angles made with this material can achieve. The reduction in weight and size is very obvious compared to instruments manufactured in steel or copper and is easy to see weights reduced by up to 30%.

The increased torque and cutting power delivered make some clinicians go through a slight learning curve when adopting the combination of a micromotor and speed-increasing contra-angle. However, the benefits including improved productivity, greater precision, and less physical and mental fatigue are all worth this small inconvenience

Setting the speed on Dental High-Speed Handpiece is generally not possible and the high-frequency operating noise is sometimes unpleasant for many users and patients. In addition, the speed is far above the required operating speed which leads to increased heating of the teeth and more wear to the rotary instrument.
In contrast, high-speed contra-angle handpiece 1:5 can be adjusted within a speed range of approximately 10.000 to 200.000 rpm. Therefore, dentists use the Increasing Contra-Angles for work that would demand a dental turbine and an additional contra-angle handpiece with an air motor.

Considering the quantity of tooth substance removed per unit of time, it is clear that a speed-increasing handpiece with water cooling is superior to turbines for grinding.

Useful tips that will make your handpiece last longer

No matter the high-speed handpiece brand you are going to buy, here are a few recommendations that every practice owner should follow, in order to ensure the maximum durability of any handpiece:

How often should you oil the handpiece?

You should oil your high-speed handpieces and contra-angle every single time you autoclave them. This procedure is now universal, as every manufacturer has guidelines to spray the oil, run out the excess buildup, and then begin the autoclave proceedings.

Where does the oil go?

A four-hole or four-line high-speed handpiece has an exhaust which is usually the biggest hole on the handpiece. Here, you don’t want back pressure building up on the handpiece which will slow the handpiece down. Instead, the smaller of the two large holes (the “drive” hole) drives the turbine where the air is going under pressure. This is where you want the oil to go.

Why should you run out of excess oil?

Running out the excess oil into high-speed handpieces and contra-angle handpieces is important for several reasons. First, it allows the oil to not “bake” into the bearings, which would cause the handpiece to become sluggish. Secondly, it allows the oil to not spray into the patient’s mouth. Finally, it allows the oil to not contaminate the operating field. In this way, flushing stations are a good option to use after lubrication in the sterilization area.

Does it matter what type of oil I use?

It is important to use only one brand of oil for the contra-angle handpiece’s lubrication. However, if you do not have strict warranty coverage to follow, the type of oil you use does not matter, as long as you consistently and routinely lubricate your handpieces.

Chemical Wipedown

In general, manufacturers don`t recommend the use of chemical wipes of any kind with your high-speed handpieces, as this process is redundant, harmful, and useless. There’s no reason to wipe the handpiece with a disinfectant (where you are just going to introduce chemicals into the head and bearings) when you’re going to kill everything through sterilization. Handpieces should be brushed under running water only to remove external bioburden before sterilization.

What causes failure in high-speed handpieces?

• Bearings (specifically the bearing cage) will generally fail first, mostly because of: Debris, excessive air pressure, excessive temperatures during sterilization, and use of a bur that is not fully seated.
• Running handpieces without burs could cause damage to the spindle/chuck assemblies.
• Irregular lubrication. We recommend lubricating the chuck at least once a week to keep it clean and functioning well. Debris can clog the chuck and interfere with holding the bur.
• The use of correct burs is crucial. One of the most common failures in dental turbines is the use of incorrect burs with less than 1,59 mm in diameter. Unfortunately, there are many thinner and softer burs on the market coming from low-cost productions and in turn available at attractive prices. If burs are too narrow, the chuck cannot hold them well. During the rotation of 300.000 revolutions per minute or more, incorrect burs will sooner or later start to deviate and consequently cause the failure of the chuck mechanism.