As noted in a recent article in Infection Control Today, “Ultrasonic cleaning has proven to be highly beneficial in today’s medical system. Small and complex medical equipment, such as endoscopes and dental instruments, cannot be cleaned efficiently using traditional methods. Ultrasonic cleaning, due to its use of small but powerful jets, can reach small crevices that are usually inaccessible by other methods.”

Ultrasonic dental cleaners are used to thoroughly remove contaminants before instruments are sterilized or disinfected*. Their use can minimize or eliminate the risk of injury that can occur when manually cleaning sharp instruments such as scalers and explorers.

This post explains how ultrasonic dental instrument cleaners help meet CDC and American Dental Association guidelines to clean reusable dental instruments and equipment.

The Science Behind Ultrasonic Cleaning Dental Instruments: Cavitation

The heart of an ultrasonic dental instrument cleaner is a process called cavitation. The equipment consists of a tank, a cleaning solution, a generator, and transducers.

The generator converts electrical energy into high-frequency sound waves, typically 20,000 cycles per second (20 kHz) and above, which the transducers then convert into mechanical vibrations. These vibrations travel through the cleaning solution, creating millions of microscopic vacuum bubbles.

When the bubbles contact dental instruments immersed in the cleaning solution they implode with tremendous force. These implosions, though microscopic, act like tiny scrubbers, blasting loose and carrying away debris, blood, tissue, and other contaminants from the surfaces of the instruments.

This method is incredibly effective because the bubbles are small enough to reach into the most intricate crevices, hinges, and grooves of dental tools—areas where manual scrubbing would be ineffective or even impossible.

For more details on this process see How Ultrasonic Cleaners Work.

Ultrasonic Dental Instrument Cleaners:  What to Look For

Whether you are responsible for a dental clinic or dental lab, consider:

• Capacity: How many dental instruments you are cleaning in a single cycle (without crowding)
• Functionality: How much control and versatility you expect from the cleaning process

As to capacity, instruments are cleaned in baskets placed inside the ultrasonic tank. Basket dimensions are always smaller than tank dimensions, so review the vendor’s specifications for both to ensure proper fit and efficiency.

As to functionality, different models offer varying levels of programmability and performance. For example, the Elmasonic E Plus Series combines useful core features with capacities ranging from  0.25 to 7.5 gallons.

Key features of the Elmasonic E Plus Series include:

• Powerful 37 kHz ultrasonic cavitation cleans quickly and thoroughly
• Eco sweep mode for uniform and gentle cleaning action
• Dynamic mode for degassing and to remove tough contaminants
• Set cleaning time and temperature with the intuitive control panel
• LED indicates when set temperature is reached
• 1 to 30 minute or continuous operation lets you “set and forget”
• 6-hour auto shutoff to avoid potential damage
• 2-year warranty

Other Applications for Dental Ultrasonic Cleaners

Ultrasonic dental cleaners are also used for

• cleaning molds
• removing plaster and cement used in fashioning bridgework
• cleaning implant hybrid prosthesis and similar restorative procedures  

Other Options for Cleaning Dental Instruments 

If your practice has additional requirements for your dental clinic or lab, Elma Ultrasonic offers additional options.  These include the Elmasonic Select and Elmasonic P series, offering expanded operating parameters and a range of cleaning solution capacities.  

How to Operate an Ultrasonic Dental Instrument Cleaner

Preparation Steps

• Until instruments are ready to be cleaned keep them immersed in either a germicidal or enzymatic presoak such as PreZyme.   Do not let instruments dry out before ultrasonic cleaning.
• Use an ultrasonic cleaning solution formulated for cleaning dental instruments.   While one might think a disinfectant solution is ideal for such applications in fact a disinfectant can make contaminants such as proteins harder to remove.
• Instead employ a detergent or enzyme solution for these applications.  An example is MedClean C7 medical and surgical instrument cleaner diluted to 1 to 3 ounces per gallon of DI water.  
• Fill the tank half full of water, add the correct amount of MedClean C7 for a full tank, add water to the fill line and activate the ultrasonic power (in Degas mode if available) to remove cavitation-inhibiting trapped air.

Cleaning Cycle

• Place the dental instruments, without crowding, in a mesh basket and suspend it by its handles into the ultrasonic cleaning solution so that the instruments are fully immersed.  
• Cleaning time (typically 7 to 10 minutes depending on the size of the load) and the temperature are set using the intuitive control panel and the unit turned on.  Note that solution temperatures should be kept below 42°C (107⁰F). Otherwise, particles could “bake” on the instruments and cannot be removed by sterilization. 

Post-Cleaning Steps

• When the ultrasonic cleaning cycle is completed, rinse the instruments in water to remove solution residue and then move to the disinfecting or sterilizing steps to complete the process.  As an interim step Barrier Milk can be used to lubricate hinges and prevent corrosion.

Important Cleaning Note

The ultrasonic cleaning solution should be changed at least once a day and the tank thoroughly cleaned and allowed to dry before being refilled with fresh solution. 

The Indispensable Tool for Cleaning Dental Instruments

An ultrasonic dental instrument cleaner is an indispensable tool in modern dental practices.

By leveraging the power of high-frequency sound waves, it provides a safe, efficient, and highly effective method for cleaning dental instruments. This critical step not only protects the health of dental professionals by reducing the risk of sharps injuries but also plays a vital role in ensuring patient safety by preparing instruments for complete sterilization.

Understanding the science behind cavitation and adhering to a strict cleaning protocol are fundamental for any dental office committed to providing the highest standard of care and infection control.

Need more Information on an Ultrasonic Dental Cleaner?

Contact Tovatech, the authorized U.S. reseller of Elma Ultrasonic Cleaners, for answers to your questions on ultrasonic cleaning equipment and cleaning solutions.

*CDC Guidelines for infection protection practices in dental settings state “Cleaning to remove debris and organic contamination from instruments should always occur before disinfection or sterilization.  If blood, saliva, and other contamination are not removed, these materials can shield microorganisms and potentially compromise the disinfection or sterilization process.”

Ultrasonic frequency is defined as sound waves above the range of hearing, nominally 20,000 cycles per second, or 20 kilohertz (KHz). The kHz designation – thousand cycles per second – derives from Heinrich Hertz (1857-1894), who discovered radio waves or radio frequency.

Ultrasonic frequency (or frequencies) is a key criterion when purchasing an ultrasonic cleaner for parts cleaning or for related sonicator bath applications.

Popular ultrasonic cleaner frequencies range from 35 kHz to 45 kHz with exceptions at both ends.

Ultrasonic Cleaning and Ultrasonic Frequency

The correct ultrasonic frequency yields superior results in terms of efficiency, thoroughness, and in certain cases avoiding damage to parts being cleaned.

Moreover, there are projects where more than one ultrasonic frequency is recommended, or when you are cleaning a variety of products calling for different ultrasonic frequencies.

Which leads into an explanation of how ultrasonic cleaners work. If you are familiar with this, feel free to skip to What Ultrasonic Frequency Should I Use?

A Brief on How Ultrasonic Cleaners Work

Understanding how ultrasonic cleaning works calls for an understanding of equipment components. At the basic, however, these units consist of: 

• Tanks to hold the cleaning solution. Tanks should be of stainless steel; their volume depends on the size of objects being cleaned.
• Ultrasonic transducers that create the cavitation (as explained below) are bonded to the bottom and/or sides of the tank.  Immersible transducers are also used.
• A generator to power the transducers
• Controls that range from a simple on-off switch to sophisticated microprocessors that govern cleaning time, sweep, pulse, degassing, temperature, ultrasonic frequency, ultrasonic power, auto safety shutoffs and other refinements. 

Ultrasonic cleaning equipment ranges from small tabletop units to huge, multi-gallon industrial cleaners.  The capacity of the cleaners has little or no bearing on the features they can offer.  Desired feature decisions are up to you, the purchaser, with help from experts at Tovatech: Elma’s exclusive master distributor in North America.

A good place to start is reviewing our post on parts cleaner specification tips and taking the time to view our learning center video on how ultrasonic cleaners work.

Another good source of info are the answers to ultrasonic cleaner frequently asked questions.

At the end of this post we offer points to consider beyond ultrasonic frequency when purchasing your ultrasonic cleaner.

The Role of Transducers in Ultrasonic Frequency

As noted above, ultrasonic transducers create the ultrasonic energy that creates cavitation that does the cleaning or sonicator bath activity.

There are two basic types of transducers: piezoelectric (a.k.a. electrostrictive) or magnetostrictive, but their function is the same. 

The ultrasonic cleaner generator provides electric current to the transducers, causing them to  vibrate at ultrasonic frequencies that in turn cause the bottom (and sides as the case can also be) of the tank to vibrate, sending sound waves through the ultrasonic cleaning solution.

This vibration forms the microscopic vacuum bubbles that implode, (not explode) on contact with items in the ultrasonic cleaner tank. This releases powerful jets of the cleaning solution that quickly and safely strip contaminants from all immersed surfaces.

The process is called ultrasonic cavitation. Ultrasonic frequency governs the cavitation bubble size, which directly affects the cleaning process.   

What Ultrasonic Frequency Should I Use?

In a sentence, the lower the ultrasonic frequency the larger the bubbles and the more vigorous the cleaning action – although the relative size of bubbles is not observable by the naked eye.

A low frequency such as 25 kHz produces (relatively) large cavitation bubbles that implode vigorously and therefore are favored for cleaning heavily soiled parts such as fabricated and cast metals or parts with coarse contaminants such as polishing pastes. 

The vast majority of cleaning operations can be performed with equipment operating at 37 to 45 kHz range. 

Complex and delicate surfaces should be cleaned at higher frequencies such as 80 kHz. The relatively smaller high-frequency bubbles release less energy upon implosion and are more numerous than those created at lower frequencies.  This means they clean more gently and are able to penetrate difficult-to-reach surfaces such as cracks, crevices and blind holes.

Higher frequencies are also recommended to avoid damaging highly polished surfaces of soft metals such as aluminum and silver.

Dual-frequency ultrasonic cleaners are a good choice if you clean a variety of products with differing characteristics.   

Matching Ultrasonic Cleaner Equipment to Ultrasonic Frequency

Here’s a representative guide to help you select Elmasonic ultrasonic cleaners delivering the right ultrasonic frequency for your cleaning tasks.  Please check the links for added details including multi-frequency options.

Points to Consider Beyond Ultrasonic Frequency

Ultrasonic “Noise”

While “ultrasonic” is defined as sound above the hearing range, ultrasonic cleaners, especially those operating a low frequencies, are not silent.

The noise emanates from vibrations in tank walls and products being cleaned, and relates to the ultrasonic frequency being used. For example, there is a significant difference in noise generation between a cleaner operating at 25 kHz and one operating at 80 kHz. 

You can reduce the impact of noise with hearing protectors and by options including sound deadening lids and noise protection boxes. 

Ultrasonic Cleaning Chemicals 

Cleaning solution chemistry is as important as ultrasonic frequency when it comes to getting the best results from your ultrasonic cleaner.

A good tutorial is our post on cleaning solutions for ultrasonic cleaning tasks.  It notes that most commonly used ultrasonic cleaning solutions fall into three categories: alkaline, acidic and neutral.  These are listed in ultrasonic cleaning chemistries.

These cleaning formulas are usually supplied as concentrates.  This means a little goes a long way.  When formulated with non-toxic biodegradable ingredients disposal concerns are eased.  Manufacturers provide dilution and cleaning temperature recommendations.

Because most ultrasonic cleaning solutions are water based there may be a concern about rusting when cleaning ferrous parts.  Rust inhibitors such as elma KS can be added to address this. 

Ultrasonic Cleaner Capacity

When purchasing an ultrasonic cleaner consider the size of the parts you are cleaning.

Most parts are placed in cleaning baskets, the dimensions of which are less than tank dimensions.

You’ll want to specify an ultrasonic cleaner tank size based on the corresponding basket size that will accommodate the parts to be cleaned.

Added to that, parts to be cleaned must be totally immersed in the cleaning solution. 

Because of this you must consider what is called the working depth of the cleaning solution. 

This is defined as the distance from the inside bottom surface of the basket to the surface of the liquid in a filled tank. 

If the working depth of the equipment you are considering is not provided or unclear from the specs, ask the manufacturer. 

Rather than go into more detail here, please check our post on selecting ultrasonic cleaner size.

In Conclusion

We hope this post is helpful when it comes to choosing the correct ultrasonic frequency for your cleaning challenges. You’ll find additional important information by viewing our informational video in our ultrasonic cleaning learning center. 

When it comes to selecting the right unit and ultrasonic frequency and other important specification details for your tasks please contact the experts at Tovatech: Elma’s exclusive master distributor in North America.

Spray guns are indispensable tools across numerous industries, from automotive refinishing and manufacturing to artistic applications. However, the very materials they apply – paints, coatings, adhesives – can become their biggest enemy when residues dry and clog critical components. A poorly maintained spray gun leads to uneven spray patterns, reduced efficiency, and ultimately, compromised results. While traditional cleaning methods often involve manual scrubbing and harsh solvents, a more advanced and effective solution exists: using an ultrasonic cleaner. This guide will delve into how ultrasonic technology can revolutionize your process to clean spray guns, ensuring optimal performance and extending the lifespan of your valuable equipment.

Investments in multifunctional ultrasonic cleaner accessories quickly pay for themselves by extending the versatility of your ultrasonic cleaner.  Examples include

• For Ultrasonic Cleaning
  • confidently complete challenging cleaning tasks
  • use diverse cleaning chemicals in a single cleaning cycle

• In the Research Lab
  • increase sample prep cycle throughput
  • accommodate multiple sample prep projects in a single run

An Intro to Multifunctional Ultrasonic Cleaner Accessories

Ultrasonic Cleaner Accessories in the Shop

A cleaning basket is a cleaning basket, right?  And as a professional, you know that it is not good practice to overload a cleaning basket or allow contact between parts being cleaned.

Imagine the basket of your benchtop ultrasonic cleaner as a condo or an apartment house with diverse occupants.

Consider a Modular Basket System allowing you to subdivide a simple ultrasonic cleaning basket into several compartments or levels…

Cross-contamination is a constant concern in all laboratory practices and can be addressed by strict operating procedures to assure equipment is thoroughly clean before use. Thorough fine mesh lab sieve cleaning used in analytical, science and testing laboratories can be crucial in meeting GLP standards.

Lab sieves, because of their design, present special cleaning challenges to assure residues from prior screenings are completely removed from fine mesh screens.

Manually scrubbing the sieves is not a sure-fire means to clean them. A time-consuming operation in itself, the chief area of concern is potential contamination of subsequent products being processed because 100% of the particles may not be removed. Moreover, manually scrubbing fine mesh lab sieves can damage them.

Tovatech offers two options for ultrasonic sieve cleaning

One is the SRH 4/200 designed to be used in conjunction with a standard Elma ultrasonic cleaner with a size 300 tank, and the other is one of the uniquely designed Easy 50R or Easy 350R ultrasonic cleaners from Elma. These two cleaners can also be used for cleaning small instruments and for sample prep.

The Elma SRH 4/200 Cleans Up to 4 Fine Mesh Lab Sieves

Safely cleaning fine mesh sieves is achieved with Elma’s cleverly designed stainless steel SRH 4/200 sieve rotation holder. It is electrically powered and easily fits onto a 300 size Elmasonic ultrasonic cleaner, such as the heater-equipped EP300H or Select 300 ultrasonic cleaners.

Up to four 200 mm (8 inch) diameter lab equipment sieves from various manufacturers are placed into the unit much as plates are loaded into a dishwasher, and held in place by rollers. Once the sieves are clamped into the holder ultrasonic energy is applied while the sieves rotate into and out of the ultrasonic cleaning bath.

Ultrasonic cavitation produced by the EP300H or Select 300 generator-powered transducers creates billions of minute bubbles that implode vigorously against the screen mesh to quickly but safely dislodge trapped particles.