9.1 Dental Radiography and Digital Imaging Asepsis

Radiography, Digital Imaging, and High-Technology Devices

Imaging workflows move rapidly between the patient’s mouth, the x-ray tubehead, exposure switch, sensor cable, scanner, and computer. Classification is based on patient contact, while the reprocessing method is based on the device’s validated tolerance.

Classify Before Choosing a Method

An intraoral positioning device, bite block, digital sensor, phosphor plate, camera head, or electronic probe that contacts mucous membranes is semicritical. CDC’s preferred approach for a reusable semicritical item is heat sterilization when the device tolerates heat. If it is heat-sensitive, high-level disinfection is the usual Spaulding alternative. For certain complex electronic devices that cannot tolerate either method, CDC describes a barrier-based exception: use an FDA-cleared barrier, then clean and disinfect the device after each patient according to the manufacturer’s IFU.

Tubeheads, exposure buttons, control panels, scanner housings, mouse devices, chin rests, and apron surfaces that contact only intact skin or are touched by contaminated hands are noncritical or clinical-contact surfaces. Barrier them before care or clean and disinfect them between patients with a compatible EPA-registered product.

Intraoral Positioning Devices

Reusable XCP rings, arms, bite blocks, and similar alignment devices contact saliva and mucosa. Heat sterilize heat-tolerant parts after cleaning and packaging as directed. If a manufacturer identifies a part as heat-sensitive, use the validated high-level disinfection method or a single-use alternative. Do not assume that every plastic component tolerates the same steam cycle, and do not treat a surface barrier as a universal substitute for semicritical reprocessing.

Before the series, assemble a clean processed set and stage enough barriers and holders to avoid opening drawers with contaminated gloves. After exposure, contain the saliva-contaminated items and transport them to reprocessing without hand-scrubbing at chairside.

Solid-State Digital Sensors

A CCD or CMOS sensor is semicritical, but not every model has the same material tolerance. First read the sensor IFU. If a model can be heat sterilized or high-level disinfected, use that validated method. If it cannot, place it in an FDA-cleared impervious barrier for each patient and then clean and disinfect the sensor and its patient-contact cable after barrier removal using the manufacturer-approved product and technique. Barrier use reduces contamination but does not eliminate the post-use reprocessing step because barriers can tear or leak.

A clean transfer sequence prevents the contaminated outside of the sleeve from touching the sensor:

1. Prepare the sensor and cable according to the IFU, perform hand hygiene, and apply a new barrier without touching its patient-contact exterior unnecessarily.
2. Use a processed positioning device. Barrier the tubehead, exposure control, and other surfaces likely to be touched.
3. After exposure, remove contaminated gloves when the dirty task is complete and perform hand hygiene.
4. Peel the sleeve away without dragging its contaminated exterior across the sensor or cable.
5. Inspect for a breach, then clean and disinfect with the exact product, wetness/contact time, and cable limits in the sensor IFU. Never immerse an electronic junction unless the IFU permits it.

Calling all sensors “nonautoclavable” is unsafe because some newer devices may have validated processes. Calling all of them autoclavable is equally unsafe. The IFU resolves the choice.

Phosphor Plates and Scanner Transfer

Photostimulable phosphor plates are also patient-contact imaging devices. Use the manufacturer’s barrier envelope and reprocess the plate exactly as directed; liquids, heat, or abrasion can permanently damage the phosphor layer. At the scanner, separate the contaminated envelope-opening step from the clean plate-loading step. Remove gloves and perform hand hygiene before touching the clean scanner interface, or use a validated no-touch workflow. Disinfect scanner touch surfaces and work areas that contaminated gloves contacted.

Do not feed a saliva-contaminated envelope into a clean scanner. Do not spray a plate with a surface disinfectant unless its IFU explicitly allows that product and method.

Extraoral Imaging and Lead Apparel

A panoramic or CBCT bitepiece that enters the mouth is semicritical: use a processed reusable part or a new single-use cover or bitepiece as the manufacturer directs. Chin rests, temple supports, handles, and control panels contact intact skin or contaminated hands; barrier or disinfect them between patients based on the workflow and IFU.

Lead aprons and thyroid collars are noncritical items. Prevent folding or crushing, store them as the manufacturer directs, and clean/disinfect them with a compatible product. Inspection type and frequency follow the manufacturer, facility radiation-safety program, and any state requirement. CDC does not establish a universal annual fluoroscopy schedule for every apron.

Intraoral Cameras and Other Electronic Devices

Apply the same logic to intraoral cameras, electronic periodontal probes, occlusal analyzers, caries-detection devices, intraoral scanner tips, and laser handpieces. Determine which component enters the mouth, whether it is reusable or single-use, and which heat, high-level-disinfection, barrier, or surface-disinfection method the manufacturer validated.

A barrier is especially useful for a heat-sensitive complex device, but it is not a license to skip cleaning and disinfection after use. Removable heat-tolerant tips are processed separately from a nonimmersible handpiece or cable. Keep clean acquisition hardware and contaminated patient-contact components separated during transport and storage.

The exam pattern is: classify the contact, follow the validated method, and preserve clean-to-dirty separation at the computer or scanner.