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Slow speed motors, attachments, and heads are absolutely used every day in the office as they are extremely versatile in their uses. As for this post, I am going to stick to the handpieces that are used for pretty much everything other than RDH and polishing. Although all of the handpieces here can be used for polishing with the right attachments; I am going to review them on their uses when it comes to removal of caries, cavity preparation, performing prophylaxis, and other endodontic and implant procedures.

I have been repairing dental handpieces for nearly the past decade, and about 30% of all of my repairs pertain to Low Speed Motors and low speed attachments When broken down, what you think was one handpiece was actually three, just put together. The motor, which connects to the airline is the most important part. It’s function creates torque, speed, and movement that carries on to the rest of the handpiece. What you are usually looking for with the motor is torque. Anything can create speed, but what good is that if it stops spinning as soon as you touch a tooth? Torque allows you to keep the speed even when you are cutting.

Next we have the Angle; also known as a Contra Angle, or a Motor-to-Angle. This attaches your motor to your head in which you insert your burs. The angle is usually a 1:1 ratio so it spins just as fast as the motor, and has just as much torque. There are some options for endodontic work that feature 4:1, 8:1, 16:1 and 31:1 ratios that allow some serious torque. All of the contra angles are interchangeable if bought for the correct motor. This allows you to customize your low speed equipment to get exactly what you are looking for. When it comes to Angle’s, get something that spins freely and doesn’t vibrate the you-know-what out of your hands, as this is the part that you are holding.

Finally, We have the Low Speed Head. This is where you insert the bur, in which you have a couple of options. First of, the one that has been around the longest is a swing latch. This allows you to open a latch to insert and remove your bur. Secondly, is the newer and very reliable push button, which works very similarly to a high speed handpiece push button back cap, just with a low speed bur. Lastly, we have a friction grip head, which works exactly the same as a high speed handpiece push button back cap, but allows you to use a high speed handpiece bur in your operations; be cautious, if you are using any real torque, this type of head will slip bur’s very easily. When it comes to heads, pick out something that you find easy to remove a bur out of. There are a lot of cheap options out there; just know that you definitely get what you pay for. If you are looking for something reliable, long lasting, and doesn’t allow the bur to move when you are putting pressure on the tooth, get a head with bearings, not bushings.

In the following post, I will break down the motors first, followed by the angles, and finish up with the heads.

 

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NSK-

NSK has a long lasting, reliable, and consistent low speed motor.  NSK motors have been duplicated ever since they were made by aftermarket companies. If you are buying something aftermarket, the engineering is likely based off of an NSK model. NSK motors operate using a vane motor. Vane motors are one of the most reliable, long lasting motors that you can use in these types of handpieces. They are simple to repair, create great speed, and generate a very consistent torque band. One thing to note about NSK Motors is that they operate at roughly 20k RPM’s and you are unable to change that to 5k, more torque driven RPM. If you are hoping to get less speed, and more torque, you will need to do that with the contra.

NSK Contra angles are straight forward; They have one single drive shaft, 2 bearings, and 1 upper gear. This allows them to have a smooth, long lasting operational life with little to no issues. As noted above, the motor has one speed, so in order to get more torque, you need to equip a contra angle with something other than a 1:1 ratio. There are several options for this, but I wouldn’t recommend anything over a 4:1 if you are putting in on the NSK 20K Pneumatic motor.

Finally, the tried and true NSK heads. NSK has a variety of options for everything you need. Most of their heads come with bearings rather than bushings. This allows them to be repaired rather than replaced, as well as giving them a longer lasting operational life. These heads have 12-teeth, which matched to NSK angles, as well as Star Angles. Just like the rest of the NSK low speed handpieces, aftermarket heads are usually nearly identical to the NSK name brand.

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Star-

Much like the NSK motor, Star handpieces also use a vane motor. They create plenty of torque and speed, while remaining reliable for long periods of time. Although their motors have the same operating principles, their is nothing else similar between the Star and NSK handpieces. Star offers to options when it comes to the attachment of their motors. They offer a quick disconnect version, as well as a standard 4-hole screw fixed back end. Star Motors also feature either a 20k option, or a much strong 5k version. They give themselves plenty of versatility, which allows you to get exactly what you are looking for when searching for a handpiece. Star handpieces are designed completely different than other brands, so when using star motors, you have to use their attachments as well; you can not mix and match with other brands.

Star Contra angles are technically called “Motor-to-Angles“. The attachments themselves are actually straight, and the angle is connected to the head. They feature 2 gears and 2 large bearings, making them long lasting and reliable. Their Star Straight nosecones are some of the most popular that I see and can be used by hygienists in the office for polishing. They develop their products using stainless steel so you do not have to worry much about corrosion, damage, dents, or anything of the sort.

As mentioned in the last paragraph, the star heads actually feature the angle, and the attachments are straight. It features three separate parts; You screw the head (1) onto the angle (2) , and you screw the angle (2) onto the attachment (3). This angle part is just a connecting piece to get the head and the attachment connected. Star heads are actually exactly the same as the NSK’s so you can mix and match. If you buy a name brand Star head, you can get stainless steel or titanium. Other than that, their design is the same as the NSK’s.  If you skipped the NSK breakdown above, go ahead and read that above; it tells you everything you need to know about the heads.

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Midwest- 

There isn’t really anything bad to say about Midwest motors. They have many different options, and they feature some of the oldest and most reliable handpieces around. The midwest shorty has is by far the oldest low speed motor that we will write about here. It has a completely different design than the previously mentioned vane motors. It actually works similar to a high speed handpiece turbine. It has a spindle and a chuck that spins and operates 2 drive rings that in turn spin the drive shaft. They even have an option to shift from 20k to 5k in some of the models; which gives you a handpiece that does everything you need. However, they are much bigger and heavier than other models of handpieces. Midwest knows that as well, which is why the developed their ‘Rhino‘ series. The rhino also features a vane motor, spins at 5k rpm’s, and is the most reliable motor I work on. Midwest is one of the worlds most known brand for a reason, and it isn’t because their handpieces aren’t reliable.

Midwest attachments are the same as their motors; long lasting, reliable, and hard working. Developed slightly different than other brands, you are unable to mix and match. Their contra angle features 1 bearing, and 1 gear; it is simple and efficient. Their outer shells are durable and are very hard to dent and scratch. Over time, the coating will begin to break down and turn black, but we are talking about decades. Their Midwest Straight nosecones are just as reliable. They feature lock and unlock chuck to make it easy to insert and remove burs.

Midwest heads have 14 teeth on the lower end, therefore, they only fit on midwest attachments. Other than the 14 tooth attachment point, they handpieces are designed just like all other models. 2 Bearings, and one main geared spindle which is spun with the drive shaft from the contra angle.

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KaVo- 

Like many other things, KaVo thinks outside the box and creates all kinds of different options. They created the INTRAflex which is a low speed motor and attachment in one, which is shown in the picture. Although the Kavo intraflex is revolutionary, it has a very small internal vane motor, and it can become very finicky over time and tends to be a bit less reliable than other models. Their standard low speed motor models are the most reliable around. The feature a vane motor that never needs attention, with sealed bearings that really never fail. Out of all my years of repairing handpieces, I rarely ever see the KaVo low speed motors. They all spin at 20K rpm’s and create plenty of torque for drilling. Their exterior shells are durable and stain resistant.

The Kavo attachments are a bit heavier than other brands, but they are beefed for a reason. They never dent and are really hard shelled. They have a ton of different options when it comes to attachments, so you can get exactly what you need. The attachment internal bearings break slightly more in comparison, but they are easily repaired. Just like most of the other brands, you have to use KaVo attachments when using a KaVo motor, as other brands are slightly different.

The Kavo Push Button heads are completely different than all other manufacturers. They insert into the contra angles and are held in place within the angle using a little retaining ball. The contra’s usually feature a rotating angle that allows you to insert and remove the low speed head. The bearings are slightly larger than other models, so the head itself is slightly larger. They are able to handle whatever amount of torque you put them under, and are a little more reliable than most other low speed heads.

Rankings-

  1. Midwest- You really can’t beat the reliability that you get when using midwest low speeds. Their motors are the most reliable, and longest lasting. They create more torque than you likely need, and they do it with the perfect amount of speed. Their contra angles are extremely durable, and handle anything that you hold them up to. Their gears rarely break, and the bearings take a long time to wear out. The heads are able to handle the torque created by the motors and are easily repaired when they do break.
  2. KaVo- As mentioned, KaVo creates the longest lasting low speed motor I have seen. They rarely ever break and if they do, they are easily fixed. The only reason that they are not in P1, is because I am not a huge fan of the contra angles. The contra angles are a bit heavier than others, and they don’t make up for it with reliability. As KaVo normally does, they like to engineer things slightly different. With so many models, you do get exactly what you want. Their heads are the best out there. Other than being slightly larger, they are way more reliable, and much longer lasting.
  3. Star- It is really hard for me to be putting star in 3rd place. Their motors are long lasting, their contra angles are some of the best, and their heads fit the standard that other brands use as well. They do everything right, but they do not exceed anything. Just as the saying goes, ” Jack of all trades, master of none”, that perfectly fits what is being detailed here. Their motors work well and give you several different options, their contra angles feature great bearings, but the gears fail often, and the low speed heads work just well enough for you to love them.
  4. NSK- I usually say that you have to do something right for people to copy you, and that is mostly true. However, the reason NSK is being copied by so many aftermarket brands is because it is the cheapest to make. It is a very simple design, and performs as such. Their motors are nothing exceptional, but still get the job done. The contra angles have a cheap shell, but are designed with a mixture of Star and Midwest. Their low speed heads are just as good as any of the other 3 (other than KaVo). They work well, but they are not exceptional.

This was a fun one to put together! It was slightly challenging as all low speed motors are so similar, and work great in their own right. No matter what you end up with, I can almost guarantee that you will be happy. There isn’t one brand that puts out a terrible product, so you can rest assured that you have something that works well. All of the brands use the same engineering with their motors, with slight changes, so it is hard for the differences to be dramatic. Contra angles are always reliable as they are simply designed, and do everything you need them to. The most common low speed repairs I do are the heads; they spin the fastest and receive the most abuse. They are, however, easy and cheap to repair. I hope you enjoyed reading! If you are looking to purchase new handpieces, or want to repair your current handpieces, feel free to contact me any time!