In the late 1970s, dentistry experienced a marked shift coinciding with awareness of the dangers posed by bloodborne infectious pathogens. It was then that the American Dental Association (ADA) Foundation’s Health Screening Program identified the hepatitis B virus (HBV) as an occupational hazard to dental practitioners and their patients. This discovery led to the first standardized infection control guidelines for dentistry, issued by the ADA. Soon thereafter, the ADA partnered with the Centers for Disease Control and Prevention (CDC) to develop additional recommendations, which, in the years since, have been continuously updated to reflect an ever-growing body of knowledge relating to infection prevention in the dental space.
In 2003, CDC released its Guidelines for Infection Control in Dental Health-Care Settings, a document that, to this day, remains the gold standard reference for preventing disease transmission in dentistry. Included among the CDC’s evidence-based suggestions are instructions for processing the instruments and equipment used in patient care.
Instrument processing, or reprocessing as it is sometimes called, is a multifaceted component of infection control – it encompasses cleaning, disinfection and sterilization of contaminated patient-care items, as well as the methods of handling, storing, and, ultimately, delivering sterile items back to the treatment area. Effective instrument-processing workflow requires specialized equipment, designated areas for reprocessing and storage, as well as a concerted effort on the part of the team to follow all relevant protocols and stay apprised of the latest infection prevention technologies and practices.
Since the 2003 guidelines were published, the fundamentals of instrument processing have remained relatively unchanged. In fact, the products and technologies now available to practitioners, combined with greater overall awareness of infection control principles, all support easier and more effective instrument-processing workflows. Evidence suggests, however, that many practices, for varying reasons, still struggle to adhere to CDC standards.
The following article reviews the steps dental teams can follow, as well as provides suggestions for products they can use to align their instrument-processing practices with expert recommendations.
Dental instrument processing: First steps
Because of the complexities inherent to instrument processing – and infection prevention in general – the CDC advises that duties be assigned to dental healthcare personnel (DHCP) trained on the specific steps for reprocessing patient-care items. The task of disseminating training to DHCP as well as creating “policies and procedures for containing, transporting and handling instruments and equipment that may be contaminated with blood or body fluids” can be delegated to at least one staff member appointed as the infection control coordinator (ICC).
PPE One of the responsibilities of the ICC is ensuring that team members are adequately outfitted with personal protective equipment (PPE). Protective eyewear, face masks, gloves and apparel (such as gowns and jackets) offer baseline protection from microbial contamination while cleaning, organizing or transporting instruments. PPE also mitigates cross-transmission of pathogens from team members to instruments. When handling or manually cleaning instruments, especially sharps, it’s advisable to use puncture- and chemical-resistant utility gloves that can be autoclaved after use.
The dental instrument-processing area
Before cleaning reusable instruments or equipment, the CDC recommends reading all manufacturer instructions for reprocessing, which “should be readily available – ideally in or near the reprocessing area.” Infection control expert John A. Molinari, PhD, notes that this area “can range from a separate, designated room organized with cleaning units and multiple sterilizers, to small spaces on either side of a sink in a multipurpose room,” with the former being more common in modern practices and more ideal for safe instrument processing. The layout of this area should feature a contaminated-to-clean workflow pattern with a clear separation between contaminated and clean workspaces.
Transportation of dental instruments
When transporting instruments to the central instrument-processing area, DHCP are advised to use a rigid, leakproof container. Cassette systems, such as Hu-Friedy’s IMS Signature Series, can be particularly beneficial here as they not only make it easier and safer to transport contaminated sharps and other instruments to the processing area, but also simplify cleaning, sterilization, storage, and chairside return delivery.
Cleaning dental instruments
Following conventional aseptic technique, all instruments, including dental handpieces and other devices not permanently attached to air lines and waterlines, must be cleaned before they are disinfected or sterilized. This step aims to remove all organic and inorganic debris which, as the CDC explains, can “interfere with microbial inactivation and can compromise the disinfection or sterilization process.” Debris removal is “achieved either by scrubbing with a surfactant, detergent and water, or by an automated process (e.g., ultrasonic cleaner or washer-disinfector) using chemical agents.” The CDC strongly recommends using automated methods over manual because they reduce the risk of sharps injury and hazard exposure, and they offer more comprehensive and time-efficient cleaning. The specially formulated solutions used in ultrasonic units contain enzymes and agents that help break down bioburden and prevent mineral buildup, spotting and corrosion, improving cleaning efficiency and extending the life of instruments.
To further enhance safety and efficiency, practices should use a perforated cassette system that can be placed directly into the cleaning unit, effectively creating a “no-touch” workflow. If items can’t be cleaned immediately after use, experts recommend using a “holding solution” or enzymatic spray gel to “presoak” the instruments – this loosens debris, making it easier to remove during cleaning. After cleaning, instruments should be visually inspected for any remaining debris and dried either by air or a function of the automated cleaning system because moisture can interfere with the sterilization process.
Dental instrument packaging
Proper packaging of instruments prevents recontamination after they’re removed from the sterilizer and placed in storage. Select packaging material approved by the U.S. Food and Drug Administration (FDA) and compatible with the sterilization method you’re using. Packaging options include bags, wraps or pouches for individual instruments. Wrapping can be used to cover perforated cassette systems before they’re inserted in the sterilizer. Some packaging may feature built-in chemical indicators to confirm sterilization efficacy, but if these aren’t present, practices should place an internal indicator inside each instrument package. If the internal indicator isn’t readily visible from the outside of the package, an external chemical indicator should be attached as well.
Dental instrument sterilization
Although sterilization is one of the most critical components of instrument processing, it’s also where most practices seem to struggle to adhere to infection prevention standards. According to the CDC, one study observed that “68% of respondents believed they were sterilizing their instruments but did not use appropriate chemical sterilants or exposure times and 49% of respondents did not challenge autoclaves with biological indicators.” Another investigation “found a high proportion (15%-65%) of positive spore tests after assessing the efficacy of sterilizers used in dental offices.” In addition, a study of Minnesota dental offices discovered that “operator error, rather than mechanical malfunction, caused 87% of sterilization failures.” Common factors that contribute to improper sterilization include “chamber overload, low temperature setting, inadequate exposure time, failure to preheat the sterilizer and interruption of the cycle.”
Several methods are available for sterilizing dental instruments, but steam under pressure (autoclaving) is the most widely used, dependable and cost-effective option for moisture- and heat-tolerant items. Staff should load packages and wrapped cassettes into the unit carefully and never overload the chamber. Experts like Molinari also suggest loading items on racks and positioning them on their edges to allow the sterilizing agent adequate room to circulate. The sterilizer should be operated according to manufacturer instructions. After a cycle is complete, items should be allowed to cool and dry completely before removing and handling. To ensure safe sterilization, CDC guidelines also advise:
- Using a biologic indicator (i.e., spore test) at least weekly and with every load containing implantable items
- Maintaining logs for each sterilizer cycle that include results from each load and comply with state and local regulations
- Label sterile packs with (at a minimum) the sterilizer used, the cycle or load number, date of sterilization, and, if applicable, an expiration date
Storage and delivery of sterile dental instruments
The penultimate step in the instrument-processing workflow is storage. All patient-care items should be stored in a way that maintains sterility until they’re used again. This can be accomplished by placing sterile packs and wrapped cassettes in a clean, dry and enclosed space, where they won’t come in contact with nonsterile items, dust, moisture or other contaminants.
Before returning items chairside for use in patient care, they should be inspected to ensure integrity and sterility. Check the packaging exterior to make sure it hasn’t been compromised in any way (torn, punctured, etc.) and confirm sterilization status using package indicators and labels. If sterile packs appear compromised, the items within should be reprocessed before being used to treat patients.
Dental instrument processing products
When it comes to instrument processing, today’s clinicians benefit from having an unprecedented variety of products and methods to choose from. Regardless of the approach used, Dr. Molinari says “the basic goal” of instrument processing “remains the same: to safely provide sterile instruments for patient care.” Contact your Patterson Dental rep for products to help you achieve this goal.
Centers for Disease Control and Prevention. Disinfection of healthcare equipment. May 24, 2019.
Centers for Disease Control and Prevention. Summary of infection prevention practices in dental settings: Basic expectations for safe care. October 2016.
Harte JA, Molinari JA. Instrument cassettes for office safety and infection control. Compend Contin Educ Dent. 2007;28(11):596-600.
Hu-Friedy. 6 critical steps for cleaning and protecting your dental instruments. May 23, 2018.
Kohn WG, Collins AS, Cleveland JL, et al. Guidelines for infection control in dental health-care settings – 2003. Centers for Disease Control and Prevention. December 19, 2003.
Maragliano-Muniz P. How I left punctured pouches behind. Dental Economics. July 1, 2018.
Molinari JA. Infection control Q and A: Instrument processing. RDH. February 17, 2016.
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A version of this article originally appeared in the March edition of OnTarget. Read the latest edition and view current promotions at pattersondental.com/dental/ontarget.