The difference between CCD and phosphor-plate

Many dentists are thinking about acquiring a digital x-ray sensor system. The question arises weather it should be a fast CCD-type with a cable or a slow wireless phosphor-plate type. To help the dentist decide, a simple summary is presented in the working difference of the different systems.

MomentCCDPhosphor-plate
Preparation of sensorTake a sterile hose.
Put it around the sensor.
Mount the sensor on the alignment gear (optional).
Mount the sensor in patient's mouth.
Take a plate from dispenser.
Extract plate from sterile hose.
Mount the sensor on the alignment gear (optional).
Mount the sensor in patient's mouth.
ExposingWalk to the timer and start it.Walk to the timer and start it.
Finishing exposure-Take plate and walk to the scanner, insert plate in the scanner.
Acquisition time CCD1.5s-5s-
Acquisition time Digora-24s
DenOptix/DigiDent-60s

Taking multiple photosSensor stay in the mouth, or is held nearby between exposures.Several plates are held ready and are exposed one by one. The plates are kept out of light and are then scanned:
Digora - 24s per plate.
DenOptix - max 16 plates are mounted, then scanned in 82s.
DigiDent - max 6 plates are mounted, then scanned in 74s.
Taking the next x-rayReset position of sensor, walk to timer and start it, wait 1.5s-2s.Extract next plate from sterile hose, mount on alignment gear (optional), reset position of sensor, walk to timer and start it, take plate and walk to the scanner, insert plate in scanner, wait 24s-82s.

Chance of saving an x-ray photo to the wrong patient card

A problem often noticed with the use of digital x-ray systems is that new photos are sometimes inadvertently saved to the wrong patient card. This can occur for many different reasons.

If the image software is not connected to the administration software, the operator must select the patient two times, resulting in higher rate of wrongly saved photos.

Image software that automatically start to acquire the image, without user intervention, can also result in more often wrongly saved photos.

If the link between the administration software and the image software is based on the patient's birth date, confusion will arise when occasionally the image software will ask the user which patient to choose (when several patients have the same birth date), resulting in more often wrongly saved photos.

The image software applications that require a single notification from the operator before acquiring the image, and that use an unique patient-identification system, will generally have the lowest frequency of wrongly saved photos.


Conclusion

It is clear that the CCD-system is better for endodontic treatments when many photos are needed while the patient is waiting. The CCD-sensor can be held ready for more photos.

However, when many treatment rooms are available, since large CCD-sensors are expensive, bitewing photos are better taken with the less-expensive phosphor-plate system.
If money is no problem, the best choice is a large and a small CCD-sensor.