Automated instrument washing


More about HYDRIM automated instrument washers from SciCan

How automated washers in dental practices improve the sterilization process

As primary health care providers, dentists are on the front line of infection control and must employ the most thorough and efficient methods available when reprocessing dental instruments. That’s why it is important that the profession as a whole continue to recognize areas that are evolving regarding patient safety and infection control.

In this context, the use of automated instrument washers is growing worldwide as regulatory authorities and dentists endorse and adopt what has come to be understood as the most effective and consistent means of cleaning instruments before sterilization.

Cleaning is the important first step in the sterilization chain. Removing the bioburden from instruments at the start must be done effectively to ensure proper sterilization. “If visible debris, whether inorganic or organic matter, is not removed, it will interfere with microbial inactivation and can compromise the disinfection or sterilization process.1 There are several methods of instrument cleaning currently in use throughout dental practices.

The hazards of manual cleaning

In this method, debris is removed from an instrument by scrubbing it manually with detergent and water. Reserved for specialized instruments, handscrubbing is increasingly less used throughout dental practices because it exposes staff to the hazards of skin punctures and can affect the productivity of the practice as it takes time away from patient care.

The limitations of ultrasonic cleaning

Ultrasonic cleaning, which removes debris by a process called cavitation where waves of acoustic energy propagated in an aqueous solution disrupt the bonds that hold particulate matter to instrument surfaces2 is also used, but its effectiveness compared to automated washing has long been under question3,4.

While manufacturers recommend changing the ultrasonic cleaning solution daily, one study found that the solution could become contaminated with debris after each successive load of instruments is cleaned5. What is more, ultrasonic cleaning requires subsequent rinsing before sterilization, adding steps to sterilization efficiency.

The challenge inherent in both these methods is its effect on human resources. As Mark Tholen writes in an article on deriving efficiencies in dental offices for Dental Economics, “Decontaminating, washing, rinsing, and drying instruments are extremely labor intensive and dramatically reduce the throughput speed of instrumentation through sterilization. Even the use of an ultrasonic cleaner does not materially enhance instrument processing speed or reduce labor.”6

He points to the automated washer as the single greatest labor-saving device in a dental office, concluding that, “when [a washer is] used in combination with cassettes, approximately one hour of labor can be saved for every nine procedural set-ups that are processed through sterilization.”

Delivering consistent, validated cleaning results

A growing body of evidence-based information is recognizing the superior effectiveness of automated washers over ultrasonic cleaning. A 2011 study published in the British Dental Journal sought to assess the level of residual protein on dental instruments cleaned in a general practice by 1) handscrubbing; 2) handscrubbing and ultrasonic cleaning; and 3) automated washing processes7. Of all the processes assessed, the use of an automated washer was the one that most reduced the variability in the cleaning.

Consistent repeatable cycles are a key advantage to using automated washers because this offers the user control. It ensures every set of instruments receives the same validated cleaning process, and cycle data is recorded to provide accurately detailed and consistent documentation that establishes an accountability baseline for instrument cleaning.

Chemical solutions that clean and protect

Automated washers are designed to operate many cycles a day to enable the efficient reprocessing of a dental practice’s limited number of instruments and most use a specialized cleaning solution that helps not only lift contaminants from instrument surfaces, but also protect the instrument from corrosion.

Hydrim, SciCan’s collection of instrument washers, uses an advanced cleaning solution called HIP Ultra.

The HIP Ultra cleaning solution is a proprietary blend of surfactants (surface acting agents), which are substances that reduce the surface tension of the water and increase its ability to lift debris from instruments. A precise amount of cleaning solution is dispensed automatically as demanded by the selected program, and the load is cleaned and rinsed using fresh water with every cycle. In contrast, ultrasonic cleaners use the same water for a day or more.

The future is automated

The powerful cleaning action of an automated washer, its ability to deliver elevated operating temperatures and its use of a sophisticated cleaning solution has made it a key starting point for sterilization in dental offices across North America. And for more than a decade, Hydrim washers have been a trusted cleaning resource as much in North America as around the world, recognized for its speed and effectiveness.

In fact, an Indiana University study commissioned to quantify Hydrim effectiveness found protein removal rates as high as 99.9%8.

Using a SciCan Hydrim L110w, a team of researchers processed a series of contaminated instruments (using dried sheep blood as a medium and coating the working ends and hinges of instruments and allowing these to dry for one hour at room temperature.)

After processing the various loads using regular and heavy duty cycles, researchers found that none of the processed instruments had any remaining visible blood or blood detectable by the Hemastix assay the study was using. In effect, and in all cases, at least 99.4% of all of the contaminating protein was removed from all instruments in every test run conducted (for some loads removal was as high as 99.9%).

Properly managing the infection control aspect of a dental practice yields not only predictable outcomes, it ensures greater productivity and increases patient care time, which creates a higher level of trust between the patient and dentist.

10 tips on getting the best cleaning results from your automated washer


  1. Remove all cement, composite material and amalgam from instruments at chairside prior to processing.
  2. Disassemble instruments if possible.
  3. When placing instruments in a basket, do not overlap. Each instrument must be kept separately.
  4. All instruments must be placed in the washer in such a way to allow proper rinsing of all surfaces. Any surface that is shielded from water and detergent will not be cleaned.
  5. Hinged instruments should be placed in a wide open position in an appropriate rack or in baskets. Closed hinged instruments cannot be cleaned.
  6. Place suction tubes in the rack for vertical instruments and ensure that water can flow unrestricted in and out of the tubes. Do not place suction tubes horizontally in a basket or in a cassette. For instruments containing lumens, such as dental handpieces, only the external surfaces are cleaned.
  7. Place trays and other concave shaped items at an angle to ensure water can run off surfaces easily.
  8. Check that the washer spray arms are free of any blockage and can rotate freely and that the mesh filters in the chamber drain are free from debris.
  9. For best cleaning results, instruments should be processed as soon as possible. If immediate cleaning is not possible, process the instruments using a Rinse and Hold program immediately after use on the patient.
  10. Do not put dental burs in your washer. They are made of carbide, which is susceptible to rusting. This can cause staining on other instruments in the load. Also, a loose dental bur in a washer can cause damage to the unit.


1U.S. Centers for Disease Control guidelines for dentistry. (

2U.S. Centers for Disease Control, Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 ( )

3Miller, C.H. et al., Cleaning dental instruments: Measuring the effectiveness of an instrument washer/disinfector. Am J Dent, 2000 Feb; 13(1): 39-43.

4Baxter, R.L. et al., Quantitative analysis of residual protein contamination on reprocessed surgical instruments. J Hosp Infect., 2006 Aug; 63(4):439-444.

5Burkhart, N.W. and Crawford, J., Critical steps in instrument cleaning: removing debris after sonification. J Am Dent Assoc. 1997 Apr;128(4):456-63.

6Tholen, Mark, 10 Ideas to Increase Production and Decrease Expenses in Sterilization. (

7Vassey,M. et al., A quantitative assessment of residual protein levels on dental instruments reprocessed by manual, ultrasonic and automated cleaning methods. British Dental Journal, 2011.

8Miller, Chris H., Cleaning Dental and Medical Instruments in the SciCan L110w Instrument Washer. White Paper Report prepared by Infection Control Research and Services of Indiana University School of Dentistry , February, 2007.