Digital Sensors: Key Advances
Twenty-five years after the introduction of the first digital radiography system, a majority of dentists are now using digital sensors. Technical innovations, including increased resolution, improved sensor hardware, better connectivity, and more, have helped the new generation of sensors provide superior image quality.
Image resolution, which has improved dramatically in recent years, is perhaps the most cited technical factor for improved image clarity. One objective measure of resolution is the number of line pairs that can be seen per millimeter. As the number of line pairs increases, it becomes harder to distinguish individual lines, until at some point one line pair is indistinguishable from the one next to it. The Schick CDR sensor has a theoretical resolution of 12.5 LP/mm, whereas the Schick 33 sensor has a resolution of 33 LP/mm.
Innovations in sensor hardware and manufacturing have also led to improved resolution. The scintillator is the component of the sensor that converts radiation energy to light energy that the sensor can “read.” In many new generation sensors, scintillators are made of cesium iodide, which is more effective at energy conversion. Fiber optic plates transmit light energy from the scintillator to the sensor. Newer fiber optic plates are more effective at light transmission, which results in better image quality. Additionally, they reduce the amount of radiation to the sensor, which results in less “noise,” a more diagnostic image, and greater longevity of the sensor.
Sensors that detect light energy to create an image also contain more pixels. More pixels mean better resolution, especially at higher magnification. In addition, new CMOS-APS technology consumes less power than previous CCD sensors.
Traditionally, images were stored and viewed using stand-alone software, usually provided by the sensor manufacturer. This option still exists and uses “bridges” to connect the imaging and practice management software. When a sensor directly integrates with the practice management software, however, there may be a more seamless workflow, as well as additional features and tools.
New generation sensors also have more connectivity options and often require fewer components or hardware. Many sensors connect to a “remote box,” which then connects to the USB port on the computer. Some sensors, such as the Dexis Platinum (Dexis, www.dexis.com) and GXS-700™ (Gendex, www.gendex.com), connect directly to a USB port on the computer. Other manufacturers, such as Sirona and Carestream, have released Wi-Fi modules.
The Planmeca® ProSensor™ (Planmeca, www.planmecausa.com) is able to connect directly to the Planmeca x-ray head, which stores electrical components and is hardwired to the operatory computer. Because the x-ray head is always near the patient when taking a radiograph, this design eliminates the need to run a long cable from the computer to the sensor. Improved manufacturing and materials have allowed for decreased sensor thickness. Shape modifications such as rounded corners or cut edges may increase patient comfort (eg, ScanX, Air Techniques, www.airtechniques.com). Most manufacturers have sensor sizes that are equivalent to film sizes, though not all manufacturers offer all sizes.
Drastic improvements in digital radiography have been made in the past 5 years. Although there is no doubt that replacing sensors can be expensive, consider how this investment can benefit your patients and your practice.
ABOUT THE AUTHORS
Andrew Koenigsberg, DDS, is partner of Gallery57Dental in New York, New York, and co-founder of CAD/CAM Excellence.
Mason Kostinsky, DDS, is chief operating officer and director of marketing and business development at Gallery57Dental, president of Infinity Practice Development, and co-founder of CAD/CAM Excellence.