Digital radiography has transformed modern dentistry through efficient image acquisition, streamlined workflows, and convenient image storage. Two common approaches are Computed Radiography (CR) and Digital Radiography (DR). Both produce digital X-ray images, but their workflows differ. 

For practices prioritizing speed and fewer handling steps, DR offers practical advantages that extend beyond the purchase price.

COMPUTED RADIOGRAPHY (CR)

CR uses reusable photostimulable phosphor (PSP) plates. After exposure, each plate is placed into a scanner to produce a digital image.

ADVANTAGES

• Thin plates can be easier to position and may improve comfort.
• Individual plates generally cost less to replace than electronic sensors.
• Multiple receptor sizes accommodate different examinations.

DISADVANTAGES

• A separate scanning step adds time and handling.
• Plates can scratch, bend, or wear with repeated use.
• Scanner upkeep and plate replacement add operating costs.
• Barrier removal and scanning add contamination-control steps.
• Plate or envelope edges may irritate sensitive oral tissues.
• May require slightly more radiation exposure than DR, depending on the system.

Lower plate replacement costs should be weighed against scanning time, contamination-control demands, and ongoing plate maintenance.

DIGITAL RADIOGRAPHY (DR)

DR uses electronic sensors, often CMOS, to capture images and display them on a computer within seconds, without a separate plate scanner.

ADVANTAGES

• Near-instant review supports efficient clinical workflows.
• Fewer processing and transfer steps; no dedicated PSP scanner.
• Some sensors support diagnostic imaging at lower exposure settings.

DISADVANTAGES

• Higher cost per electronic sensor.
• Rigid sensors may be uncomfortable for some patients.
• Repair or replacement of damaged sensors can be expensive.

DR can benefit busy practices seeking faster imaging and streamlined operations.

Cost-Effectiveness: Looking Beyond the Purchase Price

CR plates generally have a lower individual replacement cost, but a complete CR setup also requires a scanner, replacement plates, and ongoing maintenance. The extra scanning step adds staff time. DR typically requires a larger initial sensor investment, yet direct image transfer can save processing time, particularly in practices that take many intraoral X-rays. For busy practices, these time savings can make DR a stronger operational investment. Actual value depends on pricing, patient volume, durability, service costs, and workflow.

Patient Comfort, Hygiene & Infection Control

Thin plates do not guarantee comfort. Some PSP protective envelopes have sharp edges that can press against sensitive oral tissues. Poor positioning or excessive pressure may cause irritation or superficial scratches. Plate size, envelope design, and careful placement matter; DR sensors can also cause discomfort. [1]

More handling creates additional contamination points. After exposure, staff must open the protective envelope, remove the plate, and transfer it to a scanner. Saliva and microorganisms can reach the plate through a torn or poorly sealed barrier, contact with the contaminated outside of the envelope, or handling with contaminated gloves. Research has documented contamination through barrier defects and errors during plate removal. [3]

A contaminated plate may carry microorganisms into the scanning workflow, potentially contaminating scanner components or other surfaces. Maintaining a clean transfer process and separating contaminated items from clean equipment require careful technique.

Barriers alone are not a complete infection-control protocol. Use a new appropriate barrier for each patient, follow hand-hygiene and glove procedures, and clean and disinfect plates and equipment according to their manufacturers’ instructions. Use only compatible products and methods: inappropriate chemicals or processing can damage PSP plates.

DR: Direct image transfer eliminates plate removal and scanning, reducing handling steps. However, rigid sensors may cause discomfort, and sensors, cables, holders, and clinical surfaces still require appropriate barriers and reprocessing between patients. Follow manufacturer instructions and established infection-control guidance. [4] 

DR’s practical advantage: Eliminating plate unpacking and scanning removes several opportunities for handling errors and contamination. Both technologies still require consistent infection control; contamination findings do not establish a higher patient infection rate with CR.

Radiation Exposure: CR vs. DR

CR may require slightly more radiation exposure than DR, depending on the equipment and exposure settings. Some DR sensors can produce diagnostically acceptable images with less exposure than CR phosphor plates. In a phantom study comparing specific PSP and CMOS systems, the CMOS system used a shorter exposure time and produced lower measured doses at the assessed anatomical sites. [2]

The size of the difference varies by detector model and sensitivity, generator settings, patient size, collimation, and repeat images. There is no fixed percentage difference that applies to all CR and DR systems.

Extra steps can also affect total exposure indirectly. Damaged plates or handling and scanning errors may make an image unusable, requiring another X-ray. Scanning itself adds no patient radiation. Retakes can occur with either technology; proper technique remains essential. [5]

Image Quality & Ease of Use

Both CR and DR can produce diagnostically useful images. CR plates are flexible, but damage or scanning errors may create artifacts. DR provides immediate review of positioning and image quality without a separate scanning process. A clinical comparison found shorter total clinical time with the CMOS system tested. [1]

Diagnostic performance depends on the specific detector, software, exposure settings, and clinical technique; DR does not automatically produce better diagnostic images in every situation.

Final Thoughts: CR or DR?

For practices prioritizing efficient daily imaging, DR offers a compelling workflow advantage. Immediate image review, fewer handling steps, and the potential for lower exposure with suitable sensors can outweigh CR’s lower individual plate replacement cost. CR’s scanning, contamination-control demands, and plate wear should be included in any purchasing decision.

Which technology does your practice prefer: CR or DR?

Sources & Further Reading

1. Clinical comparison of intraoral CMOS and PSP detectors (2022): https://pmc.ncbi.nlm.nih.gov/articles/PMC8967495/
2. Efficacy of lead foil for reducing doses in the head and neck: a simulation study (2015): https://pmc.ncbi.nlm.nih.gov/articles/PMC4628421/
3. Infection control: microbiological contamination of PSP plates in barrier envelopes (2011): https://pubmed.ncbi.nlm.nih.gov/21929948/
4. CDC — Dental Sterilization and Disinfection: https://www.cdc.gov/dental-infection-control/hcp/summary/sterilization-disinfection.html
5. Intraoral phosphor storage plate artifacts and errors (2019): https://pmc.ncbi.nlm.nih.gov/articles/PMC6761057/