MPUS ultrasonic cleaning solution

In the recent past, there has been lots of interest in implementing the use of instrument washer/disinfectors in orthodontic offices. The convenience of using a dishwasher-type device for cleaning instruments has become more attractive for offices wishing to clear up counter space and not re-cycle cleaning fluids. The Dentronix repair department has received numerous inquiries regarding the compatibility of various washer units with dry heat sterilization and inserted-type orthodontic pliers.

The sterilization aspect isn’t nearly as important as the chemical exposure to instruments in the process. Remember that these types of cleaners and solutions were originally developed for medical instrument sterilization in large central hospital sterilization facilities. These instruments could be potentially contaminated with a significant amount of bio-burden.

This technology was transferred to the dental office in the late 1990s, still being used on basically non-hinged stainless-steel instruments.

Orthodontic instruments present special challenges, as they are particularly susceptible to chemical corrosion. Because of their multi-metals construction (often featuring non-stainless materials) and hinged joints, care must be taken in the selection of cleaning agents. Aluminum sterilizer racks and their protective anodized coatings are attacked by alkalines; tungsten carbides are attacked by even mildly acidic solutions; and the silver content in the bond that attaches the tips to the stainless pliers can create a virtual battery and cause electrolytic corrosion to tips in an acidic environment.

When Dentronix’s MPUS ultrasonic cleaning solution was originally developed in the late 1980s as a companion product to dry heat sterilization, the correct chemical balance to afford efficient cleaning and instrument protection was a primary goal.

The learning curve with acidic and alkaline disinfectants used at that time gave us a knowledge base on what to avoid. The MPUS solution was formulated to be as chemically neutral as possible. A non-ionic base with a neutral pH was selected as well as integrating phosphate-free surfactants. Because this was a “no-rinse” solution, enzymatic agents were left out to avoid the potential of chemical reactions with the dry-heat sterilization process and offensive odors during evaporation.

A powerful rust inhibitor was also included to protect instruments through the entire cleaning and sterilization process. Dentronix still manufactures and sells an updated version of this formula.

Conversely, many cleaning solutions for washer/disinfectors are not specifically designed to overcome the challenges of processing orthodontic pliers. They have been formulated to remove blood and organic debris by the sole action of pressurized, sprayed water rather than a more complex method such as ultrasonic cleaning. Without other means, these solutions must be more aggressive to be effective.

A very popular European solution uses an alkaline cleaning agent so powerful that it requires an acid rinse as a neutralizer. This can be a “double whammy” to the materials used in your ortho pliers and sterilizing racks. Alkaline detergents are available for disinfector washers with pH as high as 13. Typical formulations run between 11-12 pH. These solutions are very effective at removing organic debris; however, the level of organic debris on typical orthodontic pliers is arguably minimal.

Without question, cleaning is the most important phase of the disinfecting/ sterilization process as it reduces biological material on the instruments that can act as a barrier to the sterilization process. The reality is that in the day-to-day practice of orthodontics, the biological material most often encountered on instruments and pliers is saliva — a substance not requiring particularly aggressive cleaning agents.

The bottom line in assessing any cleaning protocol is not so much the equipment selected but the chemistry associated with it. Get MSDS sheets, check the ingredients in the formula, and ask your peers about the experiences they have had with a specific product. When in doubt, call the manufacturer of your instruments for advice before you commit to a chemical cleaning agent that could potentially damage your instrument inventory.

The cleaning and sterilization process puts enough stress on your pliers and instruments under ideal conditions without introducing damaging chemicals that weren’t designed for your protocol.