We’ve been using the piezon ultrasonic scaler by EMS since 2014 which was when Dr Chen was still in dental school! The exact model is the EMS Piezon 250 and it was provided to us during school. We didn’t have an option to choose a different brand so that’s what we’ve used.

Even after opening our own dental practice, we’ve continued to use this piece of dental equipment. The reasons were, we were familiar with it and we already had it so didn’t need to spend money to purchase additional supplies.
Since we’ve been using it from back in 2014, we’ve come to learn a thing or two about how to troubleshoot it when problems occur. Yes, parts break and malfunction but that is the normal course of life for all types of equipment.
The lesson that we’ve learned is to not panic because you can figure out what is wrong and how to fix it. The most important thing is to first identify the problem and then provide a solution.
This article will go over all of the problems which we’ve experienced with the piezon ultrasonic scaler and what we did to fix it.
Piezon unit not turning on
Sometimes the unit doesn’t turn on which may make you panic. Normally when you twist the top of it, it will light up telling you that the power is on. If it doesn’t light up even when you step on the peddle, it means there is something wrong with the power.
How to fix it
- Check all of the cords that are attached to the unit.
- Unplug and replug all of them.
- Check the power cord that is connected to the electrical outlet
- Check the electrical breaker box to make sure a switch didn’t flip.
Most commonly when it doesn’t turn on, it is usually because one of the wires are loose. This is why you need to unplug and replug all of them to make sure that they’re secured.
Another reason is also if the break switch flips in the electrical box. Sometimes you could have too many electronics or appliances plugged in and the switch just flips!
Low or no water coming out of the handpiece
You may be in the middle of a dental cleaning and you’ll notice that very little water or no water is coming out. You try to adjust the water spray knob to its highest setting but there is little change in water quantity. This means that there is an issue with something in the water line.
How to fix it

- Open the peristaltic pump quick-clip cover, which is located in the back of the unit.
- Step on the pedal and watch to make sure the peristaltic pump is rotating.
- If it is not rotating, disconnect the pump and then squeeze the two rubber cords.
- Re-install the pump and step on the pedal again to see if it is working.
- If it is working then you’ve solved the problem.

We just want you to be aware that from our experience, even if you fix the pump with this method, it is an indication that it is nearing the end of its lifespan. The peristaltic pump will usually function for a couple more weeks before needing a replacement.
We usually order a spare part once we notice this so that when it does stop working completely, you can simply swap out the part.

The photo above shows the peristaltic pump that is clogged. You can see the top cord which has a black line going through it which is mineral build up that is blocking the water from coming out.
Alternative solution
Once in a blue moon, the water issue may not be from the pump. It could be coming from the handpiece hose. You would have to swap out the hoses on different units to determine if it is coming from the hose.
If it is then you’d need to replace the entire hose. There is no intermediary solution for a non-functioning hose. Whenever the water is not coming out due to the hose, the problem is the calcium build up within the hose that is blocking the water. It is impossible to clean inside of the hose so replacement is the only option.
The piezon ultrasonic scaler is not vibrating
During the cleaning you’re stepping on the pedal but the ultrasonic scaler is not vibrating and not removing any plaque! You even try turning up the power all the way to the max but it is still not vibrating.
If the unit is on but its simply not vibrating, it could be one of two things:
- The LED handpiece went bad.
- The scaling tips went bad.

This is currently the most common problem that we have to deal with for the EMS piezon units.
How to fix it
- Try on a different scaling tip to see if it vibrates (preferrably a new one so that you know it works).
- If it vibrates with a different tip then the problem is the scaling tip.
- If it does not vibrate even with multiple tips, then it is probably the LED handpiece.

Depending on which one it is you should replace the part that is broken. After many years we’ve finally identified why this happen. It is because the scaling tips get screwed into the handpiece. Since you have to keep screwing on and screwing off the tips, the threads from either the handpiece or the scaling tips get worn out.

Worn threads means that they won’t attach properly and it’ll be loose. That will cause the entire ultrasonic scaler to NOT vibrate.
In our experience, usually about the one year mark is when the threads on all of these parts start to wear out. You should keep a log of when you bought each item and see how long they last.

Dropped the entire unit on the floor
The EMS piezon 250 unit is a tabletop piece of equipment that is marketed as “plug and play”. It does not need to be connected to a water line since it comes with its own bottle of water supply. The only downside is that it requires an outlet to plug into.
What all of this means is that there are a lot of wires and cords everywhere. It is quite easy for a staff member to trip over a cord and knock the machine over.
Personally we’ve had an instance where our doctor pulled on the cord too hard and the entire EMS unit came tumbling to the ground. It ended up with a crack in the unit and it wouldn’t turn on at all.
How to fix it
We called the technician to see if they could fix it and they recommended to send it in to them so that they can take a look at it. We shipped it out to them but got a call back a week later saying it was non-repairable.
The only solution was to replace the entire unit. Unfortunately this is one of those “issues” which just need a complete replacement. It is also one of the most costly options since you’re not replacing a single part.
The importance of knowing all of this
It would be prudent for you to know how the pizeon ultrasonic scaler works and how to fix it when malfunctions occur. It is an indispensable piece of equipment for dental cleanings and deep teeth cleanings.
It is the workhorse for removing plaque and tartar. It makes the lives of dentists and hygienists a lot easier because the scaler is electric powered. It is more effective and efficient than you ever could be with hand scalers. It is a must if you want to save yourself from hand arthritis from a long career in dentisty!
Last but not least, you really don’t want this unit being non-operational because then you wouldn’t be able to do any of the cleanings. If you wait for a technician or ship it out for repair those are a lot of days of missed work opportunities. On the other hand if you can repair it yourself, you would be operational and back in business the same day.