Consider goals as a practice; weigh merits of each system
Jun 01, 2005
Intraoral radiographs are essential to perform quality dental therapy. Teeth can be cleaned and polished without seeing radiographic images below the gingiva, but "dentistry" cannot be performed properly.
How can a diagnostic film be obtained? Intraoral film is exposed with a standard veterinary whole-body system or a dedicated dental unit and processed either manually in hand tanks or by an automatic film processor.
Alternately, a digital sensor instead of film may be exposed, allowing the images to be captured and viewed directly on a computer screen. This way is easier, economic and in many ways more diagnostic compared to the "analog" film methodology.
•Understanding digital formats Digital technologies available for dental imaging fall into two basic categories: photo sensitive phosphor (PSP) plates and digital imaging sensors. PSP technology uses an X-ray sensitive plate that replaces film. It is exposed by the X-ray unit, and placed into a scanning device, which records the latent image and converts it to a digital file in a computer within 45 seconds. While the plate is relatively rugged with less size restrictions, it must be handled in light-safe conditions similar to film. The plates need replacing after 50-500 exposures depending on the manufacturer at a cost of about $25.
Digital imaging sensors are wired directly or employ wireless (Schick) technology to communicate with the computer. The image can be viewed on-screen within seconds without additional handling or processing. The original sensors used a charge-coupled device (CCD) combined with a scintillator to produce an instant image. The process was termed RadioVisioGraphy (RVG). RVG was designed for "operative radiology" in human dentistry rather than to replace the full-mouth series of film images. During the past two decades, there have been five additional versions of the RVG — the most recent (Kodak RVG 6000 digital radiography system) is based upon a complementary metal oxide semiconductor (CMOS). With CMOS, high-efficiency, low-noise images are produced, which then are digitized and transmitted to a computer via a standard USB port. AFP Imaging, Bio-Ray, Kodak Dental Systems, Progeny, and Schick represent popular system manufacturers on the market.
A dental X-ray unit is required to expose the sensor. Traditional AC units are adequate, but if the veterinarian is purchasing all new equipment, DC generators produce a homogeneous X-ray beam that works best with the sensor. Because the amount of radiation necessary to produce digital images are less than traditional film, old dental X-ray units might need to be replaced.