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There are many health and safety challenges inherent to dentistry but undeniably one of the trickiest to manage is cross-contamination. As defined by the Centers for Disease Control and Prevention (CDC), “cross-contamination is the spread of germs from one surface to another by contact.” The danger here comes from the fact that many microbial pathogens can survive on equipment and instrument surfaces for extended periods, posing an indefinite infection risk to clinicians and patients alike.
Influenza viruses, for example, are transmittable when pathogens enter the oral or nasopharyngeal passages and can live on hard surfaces for up to 48 hours. Other disease-causing microorganisms, such as bloodborne pathogens hepatitis B and C (HBV and HCV), can survive in dried blood on surfaces for several days to a week. Scientists now also estimate that SARSCoV- 2, the virus that causes COVID-19, has a surface survival time of up to three days.
Part of the difficulty in mitigating cross-contamination in dental settings is that it can come from a multitude of sources and affect nearly every surface in the practice – both inside and out of the dental operatory. In addition, it’s generally impossible to know which contaminants pose an active threat at any given time. Even without signs of splash and splatter, contaminants may persist on surfaces, invisible to the naked eye. Subsequently, dental personnel should take every possible precaution to avoid cross-contamination and implement controls that account for both the origin and destination of infection.
Hand hygiene and PPE
As detailed in in the January 2022 OnTarget, the pandemic has made personal protective equipment (PPE) an increasingly discussed and scrutinized topic. Public health agencies such as the CDC have encouraged dental healthcare personnel (DHCP) to adopt enhanced PPE that includes “N95 (or equivalent) or higher-level respirators for all aerosol-generating procedures” as well as “eye protection (i.e., goggles or a face shield that covers the front and sides of the face)” to be worn during “all patient care encounters.” When it comes to preventing cross-contamination, however, gloves and proper hand hygiene technique offer DHCP the best possible defense.
Before donning gloves, hand hygiene, either with soap and water or an alcohol-based hand rub if hands are not visibly soiled, should be performed. Ideally, sinks will have foot controls or automatic sensors to discourage cross-contamination; otherwise, oral health professionals can simply use a paper towel to turn off the faucet.
During treatment, if the clinician needs to retrieve an item from storage, infection control experts advise against opening drawers or cabinets while wearing exam gloves or ungloving one hand, as both options create a cross-contamination risk. Certified/registered dental assistant Leslie Canham suggests that it’s a good idea instead to use overgloves, tongs, forceps or another grasping instrument to open the door or drawer and then a separate instrument like cotton pliers to retrieve the item.
Practitioners should remember that gloves are not a substitute for hand hygiene and are considered single-use items, so they must be disposed of after treating every patient. Hand hygiene also should be performed again after removing both gloves.
Dental instrument processing
Another space at high risk for cross-contamination is the instrument-processing area. While most practices have taken steps to ensure that the systems they use for transporting, cleaning and sterilizing instruments are safe and effective, there are a few often-overlooked components of the process that can create opportunities for infection.
Kathy Eklund, RDH, Director of Occupational Health and Safety at The Forsyth Institute, explains that the instrument-processing workflow should be “a one-way street,” always moving “from dirty to clean.” In practice, this means that once instruments are sterilized, they do not come in contact with contaminants until they are used again. One way to achieve this goal is by never using gloves that touched dirty instruments to open the sterilizer door so that contaminants won’t be transferred back to staff or instruments via the door after cycle completion. Likewise, when removing sterile packs, use clean, dry hands or a fresh pair of exam gloves to open the door and retrieve instruments. Once the items inside are removed, check all external pouch indicators to confirm completion of sterilization and inspect thoroughly to make sure the packaging hasn’t been compromised (torn or otherwise damaged). Finally, all sterile packs should be stored in a clean, dry, enclosed space, away from sources of cross-contamination.
Environmental surface asepsis
Perhaps the most critical aspect of cross-contamination prevention is surface asepsis. Most common dental procedures employ powered instrumentation that generates aerosols and splatter, which can subsequently land on operatory surfaces. There also is a significant possibility that DHCP will touch surfaces with gloved hands during or after treatment, transferring contaminants.
Traditionally, two possible approaches to surface asepsis can be taken: cleaning and disinfecting surfaces with appropriate products or using protective barriers. The CDC and other health authorities suggest a combination of both methods to optimize safety and workflow efficiency.
Protective barriers made of plastic or other materials are designed to cover clinical contact surfaces, protecting them from cross-contamination. Barriers are available to fit virtually all operatory items, including dental chairs, light handles, X-ray equipment, computer keyboards, reusable containers and instrument trays. These barriers are a convenient option because they reduce the overall need for surface cleaning and disinfection – after treating each patient, staff simply dispose of all contaminated barriers while still gloved and then perform hand hygiene and don fresh gloves before placing new barriers for the next patient.
Even when barriers are used, the CDC advises that DHCP perform full cleaning and sterilization of all operatory surfaces daily to minimize infection risk. If a barrier is torn or otherwise compromised during treatment, or if a surface is visibly soiled after treating a patient, that surface should be cleaned and disinfected immediately.
In terms of products for disinfection, the CDC recommends using an Environmental Protection Agency–registered hospital disinfectant unless visible contamination with blood or other potentially infectious materials (OPIM) is present; in that case, an intermediate-level (tuberculocidal claim) disinfectant should be used.
Cross-contamination prevention products
To learn more about the dangers of cross-contamination and how to prevent them, you and your team should keep up with the latest guidelines and regulations from the experts at the CDC and the Occupational Health and Safety Administration (OSHA), available on their respective websites. But to put this knowledge to work, you’ll also need the right products for the job. Patterson Dental offers a vast selection of top-quality infection prevention products, including surface disinfectants, barriers, PPE and hand hygiene solutions. Speak with your Patterson representative for our top picks for combating cross-contamination in and outside of the operatory.
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A version of this article originally appeared in the February edition of OnTarget. Read the latest edition and view current promotions at pattersondental.com/dental/ontarget.