Best Practices for Disinfection and Asepsis in Radiographic Procedures
Proper disinfection and asepsis of radiographic equipment are crucial to prevent cross-contamination in dental settings, requiring adherence to infection control guidelines and effective use of barriers and disinfectants.
This course was published in the October/November 2024 issue and expires November 2027. The author has no commercial conflicts of interest to disclose. This 2 credit hour self-study activity is electronically mediated.
AGD Subject Code: 148
EDUCATIONAL OBJECTIVES
After reading this course, the participant should be able to:
- Define the chain of asepsis required in exposing dental radiographs.
- Discuss the steps for managing surfaces and equipment in the operatory.
- List the challenges faced with infection control of radiographic equipment.
Introduction
Adhering to infection control guidelines in the dental setting is imperative to providing safe and effective care. While dental hygienists are well versed in ensuring the safety of their operatories, capturing radiographs poses another threat of contamination.
Directa USA is pleased to sponsor this important continuing education article by Kandis V. Garland, RDH, MS, CDIPC, which provides clear and evidence-based guidance on disinfection and asepsis when it comes to radiographic equipment.
Ms. Garland mentions the importance of sensor covers in maintaining the chain of asepsis when capturing dental radiographs. Directa supports oral health professionals in their efforts to provide care safely with a variety of products.
When capturing radiographs, Directa offers a high-quality protective solution designed for digital sensors in dental practices: TrollBag Sensor Cover. With a fit for every sensor on the market, it creates a reliable barrier that helps maintain a clean, safe environment for both patients and staff.
Remaining up to date on the latest infection control guidelines and ensuring the office maintains a stringent asepsis protocol are key to supporting safe treatment. Directa remains dedicated to supporting dental hygienists in these endeavors.
Best Practices for Disinfection and Asepsis in Radiographic Procedures
Proper disinfection of and asepsis with technology — including radiologic equipment — is vital to delivering safe dental care. Although radiographic duties are considered noninvasive procedures, the risk of cross contamination exists because of contact with patient’s saliva, blood, and high-touch surfaces.1-5 Typical infection control compliance failures with technology include improper cleaning, disinfection, and sterilization.6
The potential for disease transmission when performing intraoral radiographic procedures is possible due to the close contact and potential exposure to coughing, gagging, and vomiting.7-9 Proper hand hygiene and full personal protective equipment (PPE), such as gowns, mask, protective eyewear, and gloves, are required while performing radiography duties.4,5, 7
Figure 1 outlines the events in the chain of infection as well as the events in the chain of asepsis to prevent cross contamination.10 Oral health professionals should break the chain of infection while maintaining the chain of asepsis during the course of patient treatment.
Reusable patient care items must be reprocessed using Spaulding’s classification10 outlined in Table 1. Surfaces and radiographic equipment must be managed with disinfection and impervious plastic barriers. Having preplanned standard operating procedures for exposing radiographs is also prudent in ensuring the chain of asepsis.
Preparing the operatory is the first step in exposing radiographs. Oral health professionals should review radiologic procedures before the appointment and plan ahead by deciding which items are disposable, disinfected, or sterilized and then gathering the necessary supplies. Disposable supplies include impervious plastic barriers, tissue, paper towel or tray cover for at-risk counter tops, and bitewing tabs or disposable bite blocks. Surface disinfection supplies, such as premoistened wipe containers or spray bottles and gauze, are also needed.
Items to be disinfected and/or covered with a plastic barrier are organized next including the X-ray tube head, switches or controls, mouse, keyboard, and digital radiograph sensors. Finally, heat-tolerant, sterilizable X-ray beam alignment devices are retrieved and the sterile package is opened in front of the patient.
Dental instruments are categorized by the Spaulding classification into three levels related to sterilization needs: critical, semicritical, and noncritical (Table 1).10 Critical instruments penetrate soft tissue or contact bone or the bloodstream and therefore must be heat sterilized. Sterilization refers to a process that kills all living microorganisms, including bacterial spores by one of three methods: heat, gas, or chemical.11
No critical items are used during dental radiography duties. Semicritical instruments (digital radiographic sensors and holders, mouth mirror, amalgam condensers, reusable impression trays) contact mucous membranes but do not penetrate soft tissues and should be sterilized whenever possible if heat tolerant. Digital radiographic sensors are semicritical items that cannot be heat sterilized thus requiring additional steps including disinfection with an Environmental Protection Agency-approved intermediate level (tuberculocidal) disinfectant and covering with a Food and Drug Administration (FDA)-approved impervious plastic barrier.1,2,5,9,10 Noncritical items (X-ray tube heads, switches, buttons, blood pressure cuffs, or stethoscopes) only contact the skin and can be disinfected and/or covered with a plastic barrier. Disinfection is a process that kills many microorganisms, but not all bacterial spores.11
Managing Surfaces and Equipment in the Operatory
Two types of environmental surfaces are used in the dental operatory: clinical contact and housekeeping. Clinical contact surfaces include items frequently touched during treatment (devices, equipment, switches, and handles) that require disinfection and/or barriers between patients. Housekeeping surfaces (floors, some counter tops) that are not directly touched during treatment only require cleaning.10 However, counter tops upon which digital sensors or holders rest require barriers and/or surface disinfection.Surface disinfectants are used for clinical contact surfaces and may also be used on housekeeping surfaces as a time-saving method. Three types of surface disinfectants are used for a variety of surfaces: low level, intermediate level, and high level.
Low-level disinfectants carry a “hospital disinfectant” claim, meaning the product is used for housekeeping surfaces not contaminated by blood or other bodily fluids.10 Low-level disinfectants are effective against the test organisms S. aureus, Salmonella, and Pseudomonas and are effective against human immunodeficiency virus and hepatitis B virus (HBV).10
Intermediate-level disinfectants also carry a “hospital disinfectant” claim and include all of the same characteristics as low-level disinfectants but are also effective against the hearty test organism Mycobacterium tuberculosis. This means it is considered “tuberculocidal” and is effective for use on items or surfaces contaminated with blood or other bodily fluids.10 Intermediate-level disinfectants are used on all surfaces in the dental operatory because aerosols, blood spatter, and other fluids may be present but invisible to the naked eye. Using one product might be more cost effective and improve staff compliance. As long as the label claims tuberculocidal activity, it is considered an intermediate-level disinfectant.
High-level disinfectants are not recommended due to their toxic nature to skin, mucous membranes, and lungs; they are not used as surface disinfection. High-level disinfection may be used for semicritical items that cannot be heat sterilized and must be submerged for a contact time depending on the manufacturers’ instructions for use (IFU).10 Current autoclave technology offers cycles eliminating the need for high-level disinfectants.
Surface disinfectants require cleaning or removing blood or other bodily fluids first by a spray and wipe method, or a wipe and discard method.10 Next, the surface must be sprayed or wiped a second time and left wet or damp for the manufacturer’s contact time, which can be time consuming. Failure to perform both steps results in surfaces that are not disinfected.
Plastic barriers are additional measures to prevent cross contamination and disease transmission in the dental operatory. The 2003 CDC Guidelines emphasize that barriers are effective for difficult-to-clean items such as electronic devices.10 Barriers composed of impervious plastic are alternatives or adjuncts to surface disinfection to prevent contamination from potentially infectious moisture and include plastic wraps, sheets, tubing, and bags.10,12,13
Placed on clean surfaces at the beginning of the day, barriers are changed between patients. The surface under the barrier does not need to be disinfected as long as the barrier was not compromised or visibly soiled.10,12 Barriers are one-time use items recommended for hard-to-clean items (fixed equipment, light handles, switches, chair controls, X-ray tube head, and exposure buttons), speeding operatory turnaround time.10 FDA-cleared barriers must be used on semicritical items such as radiography sensors and holders.2,10 A combination of barriers and surface disinfection is recommended for radiographic equipment.2,10
Infection Control Challenges with Radiographic Equipment
Many types of electronic devices are used in dentistry today including radiographic equipment. The CDC’s “Guidelines for Infection Control in Dental Health-Care Settings — 2003” recommend consulting manufacturers’ IFU for each device.10 An IFU should provide detailed instructions on the cleaning and maintenance required to safely protect the device and abide by infection control protocols. The FDA also provides suggestions on the labeling and IFU of medical devices.14
Heat sterilization is required for semicritical items whenever possible, however, many devices such as digital radiographic sensors cannot withstand heat sterilization.10 In that case, the use of both intermediate level disinfection and FDA-accepted impervious plastic barriers is required.10
Portable handheld radiography units require the use of plastic barriers along with a disinfection with less than 17% alcohol content.15 Digital radiographs are one of the most commonly used devices. Intraoral cameras are used very similarly and as frequently as digital radiography, suggesting similar cross contamination risk. Both digital radiography sensors and intraoral cameras require barrier protection and intermediate-level disinfectants and wiping with isopropyl alcohol and gauze for the intraoral camera lens.16,17
Capturing radiographic images requires the use of a radiation source (tube head or handheld unit) and a radiographic receptor (film or digital sensor). The radiation source is activated and captures an intraoral image onto the receptor. Digital radiographic sensors have mostly replaced film are more commonly used in dentistry today.18
There are two types of digital sensors: direct and indirect.2 Direct sensors — known as charge-coupled devices or complementary metal oxide semiconductor devices — are composed of a semiconductor housed within a hard plastic casing with a cable that is connected directly from the sensor (semicritical item placed in the mouth) to the computer, so images are immediately captured and appear on the computer screen.2
Indirect digital sensors are made of photostimulable storage phosphor plates (PSP) that are similar to film in size and shape which then must be scanned into the computer before viewing.2 Indirect sensors are used less commonly than direct digital sensors but are another option to improve patient comfort and reduce problems with gagging.18 Direct and indirect digital sensors must be handled with an aseptic technique.13 Hamedani and Farshidfar8 recommend a “no touch technique” for processing film and PSPs. Table 2 differentiates the steps needed for maintaining the chain of asepsis with various receptors.
Plastic Barriers and Disinfection
Impervious plastic barriers help prevent cross-contamination on devices and equipment. The 2003 CDC guidelines emphasize barriers for difficult-to-clean items such as electronic devices and radiography equipment.10 Barriers alone are not adequate to prevent cross contamination and may provide the clinician with a false sense of protection of semicritical items.
Challenges related to barrier thickness exist. Thicker barriers make capturing digital images more difficult for clinicians and may inhibit the effectiveness of the device, as well as cause more discomfort for patients.19 Thinner barriers are recommended for these devices. Barriers are recommended for all semicritical devices and the most effective thickness is a low-density polyethylene.19 Barriers should fit the receptor tightly and have a long enough sleeve to cover the cord.
Cleaning and disinfection of direct digital sensors must be done to maintain the chain of asepsis. After use, plastic barriers should be removed and the sensors and cord should be carefully disinfected using an intermediate-level disinfectant with a wipe-discard-wipe or spray-wipe-spray method for the manufacturer’s dictated contact time. Skipping this step could lead to cross contamination. Table 2 lists the aseptic steps necessary for radiographic receptors.
A combined approach is considered best practice with regard to radiography devices and equipment.2,10,12 The protection and maintenance of expensive radiographic equipment are essential for longevity and function; however, oral health professionals must keep asepsis of radiographic equipment in mind and follow prudent infection control guidelines.
References
- de Souza, T., de Castro, R., de Vasconcelos, L., Pontual, A., de Moraes R, Pontual, M. Microbial contamination in intraoral phosphor storage plates: the dilemma. Clin Oral Invest. 2017;21(1):301-307. DOI: 10.1007/s00784-016-1790-7.
- Gumru, B. Tarcin, B., & Idman, E. Cross-contamination and infection control in intraoral digital imaging: A comprehensive review. Oral Radiology. 2021;37(2):180-188. DOI: 10/놟/s11282-020-00452-z.
- Ilhan, B., Bayrakdar, I., & Orhan, K. Dental radiographic procedures during COVID-19 outbreak and normalization period: recommnedations on infection control. Oral Radiology. 2020;36(4):395-399. DOI: 10.1007/s11282-020-00460-z.
- Sushanth, A., Srivastava, K., Srivastava, D., Hosni, H., Khan, Z., Al-Johani, K., Alzoubi, I., Sghairneen, M., & Alam, M. Recommendations, practices, and infrastructural model for the dental radiology set-up in clinical and academic institutions in the COVID-19 era. Biology. 2020;9(10):1-14. DOI: 10.3390/biology9100334.
- Alakhras, M., Al-Mousa, D., Mahasneh, A., & AlSa’di, A.Factors affecting compliance of infection control measures among dental radiographers. Int J Dent. 2020;8834854:1-11. DOI: 10.11/蒃/떔/䚦.
- Malta CP, Damasceno NL, Ribeiro RA, Silva CSF, Devito KL. Microbiological contamination in digital radiography: evaluation at the radiology clinic of an education institution. Acta. Odontal. Latinoam. 2016;29(3):239-247.
- Nayak, V., Shetty, U., Rao, P., & Kini, R. Coronavirus disease-2019: Infection control and prevention measures in dental radiology. Gulhane Medical Journal. 2022;64(1):126-127. DOI: 10.4274/gulhane.galenos.2021.43534
- Hamedani, S., & Farshidfar. The practice of oral and maxillofacial radiology during COVID-19 outbreak. Oral Radiology. 2020;36(4):400-403. DOI: 10.1007/s11282-020-00465-8.
- Pamukcu, U., Tetik, H., Peker, I., Atas, O., & Akarslan, Z. Effect of enveloping and disinfection methods on artefact formation on enveloped PSP plate images. Oral Radiology. 2022;38(4):558-564. DOI: 10.1007/s11282-022-00587-1.
- Centers for Disease Control and Prevention. Guidelines for infection control in dental health-care settings-2003. MMWR 2003;52(RR-17):1-66.
- Miller CH, Palenik CJ. Infection control and management of hazardous materials for the dental team. 7th ed. St. Louis, MO:Mosby, Elsevier:2023.
- Centers for Disease Control and Prevention. Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care. Available at: https://www.cdc.gov/dental-infection-control/media/pdfs/떘/葓/safe-care2.pdf Accessed July 22, 2024.
- Soares, C., Braga, S., Ribeiro, M., Price, B. Effect of infection control barriers on the light output from a multi-peak light curing unit. J Dent. 2020;103(1):1-7. DOI: 10/놨/j.jdent.2020.103503.
- Food and Drug Administration. Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling by the Food and Drug Administration. Available at: https://www.fda.gov/media/ɩ/download?attachment Accessed June 29, 2024.
- NOMAD disinfection guidelines. Available at: https://aseptico.com/wp-content/uploads/떖/葏/ARU-07KP2-NOMAD-Pro-2-Manual.pdf Accessed June 29, 2024.
- Schick Digital Radiography Sensor Cleaning and Disinfecting. Available at: https://www.dentsplysirona.com/en-us/discover/discover-by-topic/by-category/imaging/cleaning-and-disinfecting-sensors.html Accessed August 15, 2024.
- Schick Intraoral Camera Cleaning and Disinfecting. Available at: file:///C:/Users/kandis.garland/Downloads/usbcam4_userguide%20(2).pdf. Accessed June 25, 2024.
- Chauhan, V. & Wilkins, R. A comprehensive review of the literature on the biological effects from dentalX-ray exposures. International Journal of Radiation 2019;95(2): 107-119. https://doi.org/葖.1080/潪.2019.1547436
- Choi JW. Perforation rate of intraoral barriers for direct digital radiography. Dentomaxillofac Radiol. 2015;44(3): 20140245.
- Ianucci J, Howerton L. Dental Radiography Principles and Techniques. 6th ed. New York: Elsevier; 2022.
From Dimensions of Dental Hygiene. October/November 2024; 22(6):35-39.