The cleaning of reusable dental instruments prior to heat sterilization is a crucial, yet sometimes misunderstood, infection control procedure. If biological contamination is not removed by proper cleaning, the remaining bioburden can interfere with the lethality of the sterilization cycle. Cleaning should be performed as soon as possible, in a designated area, using the appropriate personal protective equipment.
Be sure to clean instruments according to the manufacturer's instructions for use, paying attention to detergent type and dilution, water quality, and temperature. Be sure to use approved cleaning solutions as household products not intended for use with instruments can cause damage and or limit cleaning effectiveness. If cleaning cannot be performed immediately, pre-soaking the instruments in a neutral pH detergent or enzymatic cleaner will prevent drying of the bio-burden in dental materials to make the cleaning easier and less time consuming. There are manual and mechanical methods of cleaning. Considerations in selecting cleaning methods and equipment include their effectiveness, their compatibility with the items to be cleaned, and the occupational health and exposure risks they pose.
Because instruments cleaned with automated cleaning equipment do not need to be pre-soaked or scrubbed, the use of automated equipment can increase productivity, improve cleaning effectiveness, and decrease worker exposure to blood and bodily fluids. Thus using automated equipment can be more efficient and safer than manually cleaning contaminated instruments. If manual cleaning is indicated, heavy duty utility gloves must be worn along with using a long handled brush to avoid a sharps injury.
Scrubbing single instruments submerged in a sink halfway filled with water will decrease spatter. Remember, if it's not clean, it can't be sterilized. The vast majority of dental offices use an ultrasonic cleaner, which generates sound waves, causing bubbles to develop within the solution.
The cleaning action occurs when energy causes the bubbles to implode, producing a continuous shock wave of cavitation on the surface of the instruments. It is critical to follow the manufacturer's instructions for use. Water is not an ultrasonic cleaning solution. Enzymatic or detergent solutions designed for ultrasonics not only provide the ability to disrupt the bioburden, but are also compatible with the instruments to reduce corrosion and extend the life of the instrument.
Ultrasonic solutions must be discarded or replaced at least daily. Never should an ultrasonic tank be topped off with added solution. A maximum of two layers of instruments should be placed in the basket and must be covered fully by solution. Once the instruments have been placed in the basket or closed cassettes on a tray, the lid must be closed before activating the unit to ensure no splatters or aerosol exposures.
Do not add additional instruments to the basket once a cycle has begun. Ultrasonic units should be tested periodically for proper function using the aluminum foil test following the manufacturer's recommendations. Once the cleaning cycle is complete, use the handles to lift the basket and rinse thoroughly under running water to remove any loose debris and cleaning solution. This rinsing prevents instrument spotting, staining and pitting.
Instruments should be visually inspected in a good light source for any residual materials and allowed to dry thoroughly before being packaged. Instrument washers are not as commonly used in smaller dental practices, but are becoming more common in large practices as well as schools and clinics. Instrument washers and disinfectors are more efficient at pre-sterilization cleaning than either ultrasonic or manual cleaning. These washers will accommodate larger quantities of instruments and provide a higher level of automation of the instrument cleaning process, since the instruments are not only cleaned, but rinsed and dried within the units.
These machines are considered FDA cleared medical devices and have passed various certifications for use in health care facilities. It is not acceptable to use a domestic dishwasher to process dental instruments. Following the cleaning and drying process, instruments are ready for inspection to make certain they are free of any debris and in good working order before ready to be packaged for sterilization. If the instrument is in need of repair, be sure to set it aside. In addition, be sure to check each instrument for proper function and lubricate as required by the instrument's manufacturer's IFU.
Identification color-coded tapes on instruments must not be used as these can prevent the penetration of steam under the tape, may harbor microorganisms in the adhesive layer which may result in detachment of the tape during treatment, thereby compromising patient safety. Additionally, silicone rubber rings used for instrument identification may not allow the sterilant to penetrate.