Digital radiography: Proving better all the time

April 1, 2005
In the previous two articles, we looked at the types of digital radiography, or DR, systems as well as the costs and ROI. But what about potential use and value of DR in dental practices?

By Paul Feuerstein, DMD

The common perception is that DR is better served by practitioners who perform endodontics, surgery, or implants. These obvious examples make sense - especially when talking about wired and wireless sensors. It takes virtually no time to determine if a file is at the apex of a tooth, and if it’s not, it just takes seconds to reposition the file or film and retake it. There is no getting up for developing, reading a wet film, retaking, etc.

Implant placement yields the same and also helps in treatment planning. Some programs employ calibration algorithms while others include libraries of actual implants that can be electronically placed in the ­radiographic image to help find the proper size and design. For a specialist in this situation, another positive is the ease of duplication and getting the information to a referring dentist. This can be done by printing or via electronic means. In the former, several digital radiographic software programs have simple forms built in that allow an office to print the note with minimum mouse clicks.

In determining which system to purchase, dentists should look at the report generator and see what forms are preset and how easy it is to customize one for a practice. Kodak makes a wonderful paper for printing called Medical Imaging Paper. As far as electronically transferring the images, most programs have a vehicle for emailing, transferring to a disk, or embedding in an electronic report, which can be sent. If a recipient has the same software as the sender, data from some programs can be sent in raw formats. The recipient can read the images with the same software and put the images into patient files on his or her own system. Otherwise, images must be converted to universally acceptable file forms such as JPEG or TIFF. Some of these conversions use compression, so images are not as crisp as originals. Even if a recipient uses a different DR program, most allow importation of new images and usually are clinically acceptable.

One other possibility is including a viewer program with images so recipients can read them with the same clarity as senders.

There is a lot of work on compatibility being done behind the scenes. Current systems put images in a ­DICOM-compliant format. This is not the same as having the images in a universal format. A full discussion of DICOM is beyond the scope of this paper, but in summary, this format gives an image a digital stamp with much information about how the image was taken. It also ensures that it is the original, unaltered image, which is important from a legal standpoint.

The American Dental Association is investigating the best method to make this a simple, clear system for all offices. They have defined seven scenarios of office transfers of images and have made recommendations for each. The information is available on in the proposed ADA Technical Report 1023.

In an average dental practice, how can DR be an asset? Take two practical scenarios - the emergency patient and a radiographic-based diagnosis. In one situation, a woman calls with a toothache. The office has a 15-minute block that was reserved with a short overlap into the next time slot. She is seated by the assistant and says that the “back tooth” is bothering her. The assistant proceeds to take a periapical film, runs off to the developing area, uses a quick solution, comes back to the room, and hangs the wet film on the viewbox. The doctor enters the room, glances at the film of the heavily restored second molar, and begins explaining to the patient what the possible problem might be. As the doctor points to the tooth, the patient says, “Not that back one,” and points to the second premolar, which was not evident on this PA film. Again, the assistant comes in (usually in a huff), takes another film, develops it, and this time the wet film shows a carious exposure in the premolar. The entire visit at this point was about 15 minutes - the allotted time for the visit. Unless the practitioner can double book the anesthesia of this hot tooth, the patient may be put on medications and rescheduled rather than disrupt the next patient’s crown preparation.

Had this been done with a sensor, the entire process would have taken no longer than two minutes, and the patient would have been numb and free from pain. This adds to the quality of care in the patient’s eyes and adds a few dollars to the daily production. The ROI here is obvious.

In another instance, a patient comes in with pain in a previously endodontically treated molar. The assistant takes the PA, and the wet reading reveals a widened PDL on the apex of the distal root. This explains why the patient’s “dead tooth” was hurting. Of course, it requires a magnifying glass and a lot of explaining to the confused patient. Had this been shown on a 17-inch monitor with the proper filters, it would have been clear to the patient and dentist after seeing this problem.

I pause here to remember the late Dr. Robert Barkley, the pioneer of practice management. One of his philosophies was co-diagnosis where problems were demonstrated to the patients in such a way that they would ask for specific treatment solutions. The mysterious black, gray, and white radiograph in large digital form can be a teaching tool all of a sudden. Practitioners could recount countless examples in which the time savings or visuals aided in the practice flow.

I recently spoke with Dr. Ken McPartland, a periodontist in Chelmsford, Mass. Dr. McPartland recently remodeled a terrific office for maximum patient comfort, including use of Feng Shui (an interesting concept for readers to study). He was resistant to DR in his specialty. He had reservations about how the technology would work in a periodontal practice that (except for implants, which had recently entered his protocol) had no real need for instant, digital films. Having recently become a Diplomate of the American Board of Periodontics, Dr. McPartland was looking for a higher level of treatment for his patients.

He decided to install computers throughout his office, eliminate most of the clutter through his practice-management software, and thought DR was necessary to achieve this. His initial thoughts were more about eliminating physical files and mounts, lost films, and allowing easy duplication to his referring dental offices. After installation, though, he found a myriad of other advantages. His X-ray processors had required a lot of maintenance with solution and the mechanics of the processor itself. He also had been finding variation in the quality of images among staff members. His initial visit included about 20 to 25 minutes or more to take radiographs, develop them, and mount them, and if more than one referral office needed film copies (he was already taking double film packs), duplication was necessary. In most cases, patients were reappointed for re-exams, consults, and reviews of the radiographs.

Now, as the films are taken, he can access them on the computer in his private office. As soon as the series is taken and displayed on the screen in front of the patient, he can walk in and begin going over the findings. This system has eliminated patient follow-up visits. In addition, now that Dr. McPartland places implants, the software has some nice calibration features that aid in treatment planning and help during placement.

Many offices use panoramic radiographs supplemented by bitewings and strategic periapicals. There are a few solutions to retrofit an existing pan to make it digital. A couple of companies manufacture a piece of hardware that replaces the area that currently houses the film cassette. These conversions are costly, but certainly less than purchasing a new machine. A less complex alternative is getting a panoramic phosphor plate that merely goes where your film was. These cost less than $1,000 and are placed in the digital “developer” (scanner). The images from these retrofits are adequate, but are no match for the new digital panoramic machines. The new systems have computerized movements, fire the beam at varying speeds and intensities in different parts of the scan, and are almost equivalent in quality to individual periapical images. They also can be digitally enhanced, filtered, etc.

The crystal ball of DR can be seen in products by Imaging Sciences, Hitachi, J. Morita, Aperio, and others that have created what appears to be CT-like scans. These units (except Aperio’s NewTom) resemble large panoramic machines, but deliver 3-D slices through the maxilla and mandible with conebeam tomography. They allow us to see X, Y, and Z axes showing specific locations of impacted teeth, nerve canals, bone structures, TMJ, and even searching down root canals and bony perio pockets. The software allows a virtual model to be created on the screen to allow for an excellent visual reference. Despite the complexity, these scans are as quick as 17 seconds and have low radiation exposure.

The implications for developmental analysis as well as implant placement are easy to foresee. Images can be exported to other programs (being DICOM compatible) and offer another new dimension to dentistry. New software programs with names such as SimPlant and RoboDent take these 3-D images and do a precise treatment plan of implant positioning and size and actually make a physical surgical stent that can guide the placement of the drills and implants themselves. A future article will review this exciting new vista in dentistry.

This all still might seem like a frill to some practitioners, but there might be some necessity in the future. In the December 2004 JADA, Dr. Titus Schleyer examines the NHII, or National Health Information Infrastructure. This is “an initiative to help establish a national, electronic information network for health care” set up by the U.S. government in hopes that all medical records will be digital by 2014. This is an oversimplification, but rather than it being a threat of becoming law, it ­behooves the dental profession to join the rest of the medical profession in allowing an easy, electronic exchange of patient records. Digital radiography will be an integral part of this system.

Armed with the information presented in this series, the practitioner must choose the right system for his or her dental practice. Companies are competitive, which is a mixed blessing for us. On one hand, it is usually a large, one-time initial purchase, so the salespeople have to work hard to show the benefits of their particular systems. On the other, due to the competitive nature, the products are getting better quickly. Many practitioners think that if they wait long enough, the cost will go down. Companies are not going to sell thousands of units per week. Each sale has to be backed up by research and ongoing development of the product along with the support and training team behind it. If companies make minimal profits, they cannot survive, as was shown a few years ago by a company that tried to undersell the marketplace. The cost of the system will be a factor, but the practitioner has to realize the value of digital radiography in the practice before making this commitment. The product should be demonstrated and tried by the practitioner, hygienists, and assistants in the practice. This can be done at most dental meetings or in your office. Most companies have demo units that can visit your office. The tough questions have to be asked about things such as warranties, ongoing support costs, replacement costs, and rapid response time. The debate also rages about sensors vs. phosphor plates.

Some offices have answered this call by having both. This is usually found in a large office where the costs of multiple sensors seem to be overwhelming, although, as was pointed out in this series, it is just a shift of budget to make it all happen. These offices opted to have phosphor plates for the routine full or bitewing series, with sensors in use for the emergency, endo, implant, etc., as discussed. Sometimes staff members get comfortable with the digital solution and evolve to an all-sensor practice. A lot comes down to a comfort zone of the practitioner and staff.

Digital radiography is here to stay. In your mature, comfortable practices, it will seem to be a great upheaval until you make the decision and jump in. For the new practitioner, it is an opportunity to have a totally modern, digital, paperless office from the start. Read this series and any articles you can find on the technology. Go to seminars, meetings, hands-on courses, and educate yourself, but don’t use this as an excuse to procrastinate. NIKE says it best - “Just do it.”

Dr. Paul Feuerstein installed one of dentistry’s first computers in 1978. For more than 20 years, he has taught technology courses. He is a mainstay at technology sessions, including annual appearances at the Yankee Dental Congress, and he is an ADA Seminar series speaker. A general practitioner in North Billerica, Mass., since 1973, Dr. Feuerstein maintains a Web site ( and can be reached by e-mail at [email protected].