Is digital-imaging technology right for you?

Dec. 1, 1999
Diagnostic imaging is a critical aspect of every practice. Dentists need to capture and view radiographic information about the oral health of their patients.

Richard W. Brown

Diagnostic imaging is a critical aspect of every practice. Dentists need to capture and view radiographic information about the oral health of their patients.

Today, more diagnostic-imaging options exist than ever before. The evolution of film technology provides options that include high-speed emulsions. Digital-imaging technology provides equipment that some dental practices will find useful for particular applications.

The trick is deciding which type of imaging technology is best for which application. Make the right decision, and you leverage the best the industry offers.

Silver halide X-ray film remains, for the vast majority of dental practices, the ideal approach for dental-radiographic imaging. There are a number of reasons for this.

First, there?s image quality. No other imaging technology available to dentists today has the potential to capture as much raw information as film. One measure of this capability is resolution (the ability of an image to depict nuance and detail.) Film has shown that it can capture significantly higher resolution than direct digital-radiography (DDX) sensors. Another measure that underscores film?s strengths is its ability to capture shades of gray. X-ray film is an analog media; i.e., it captures and presents essentially continuous shades of gray. Digital images, on the other hand, are mathematical renderings. They depict shades of gray in discreet increments. The difficulty is that typical computer monitors support the display of only 256 shades of gray. This can represent a drop in quality compared to looking at a piece of film mounted on a viewbox.

Also related to image quality is the relatively wide exposure latitude of film. Film is relatively forgiving if exposure settings are too high or too low. You are less likely to lose detail if your exposure times are not quite right.

A business decision

An important consideration in deciding which technology will work best for your practice is the cost to install and run different types of imaging equipment. In some aspects, digital-imaging technology is still too new to fully understand its costs.

For example, integrating a digital-imaging system into a practice will cause disruptions. Staff will need to be retrained. Work-flow patterns will change. What will be the impact of these changes? What effect will the cost of printing these images have on the overall operating cost of the system? Will some jobs take longer than they do today? For the time being, the answer to these questions are unknown.

Other factors that are still poorly understood include:

* How vulnerable dental digital imaging equipment would be to system failure.

* How events like hard drive crashes would affect the cost of using digital-imaging systems.

* How often digital hardware and software upgrades would be necessary.

* How upgrades would impact overall system costs.

While these factors are not understood, it is possible to estimate some costs associated with digital-imaging applications. We know, for example, the purchase price of direct-digital radiography systems, as well as the annual cost of infection-control sheathing for DDX sensors and the cost of system-maintenance contracts. Add these up, and DDX systems could cost significantly more than film-based systems on a per-image basis.

For example, consider a practice that generates 5,000 intraoral images per year.

To use direct-digital radiography, the practice would most likely need to purchase several DDX systems (one for each chair where imaging would be performed) at a cost of about $10,000 per system.

One DDX manufacturer has stated that it sells an average of 2.5 systems per customer. Let?s use that figure for the purpose of this analysis. Amortized over four years, the equipment cost would be $6,250 per year. Infection-control sheaths for the sensors would cost another $540 per year, and the DDX system maintenance contract would be $800. This works out to a cost of $1.72 per image.

However, this same practice, using film, incurs costs of 57 cents per image, given the following information:

* A high-end, automatic film processor with a purchase price of $5,500, which would amortize over a four-year lifespan to $1,375 per year. (A four-year amortization is used here for purposes of comparison. In fact, most film processors are in operation for much longer than four years).

* Film cost (based on a 10-box discounted price, offered in a recent issue of a leading dental-product dealer catalogue) is 21.3 cents per image.

* Chemistry cost for daily replenishment, at an 8-ounce-per-30-films replenishment rate, is 3.7 cents per image. (This cost is based on a four-case discounted price, offered in a recent issue of a leading dental-product dealer catalogue).

* Chemistry cost for monthly replacement of chemistry is 4.3 cents per image.

This analysis shows that using film for capturing images costs less than half as much as a DDX system.

Additionally, DDX manufacturers often claim improved practice efficiency as a result of the use of their products. This claim is based, in part, on the assumption that, while dental films are being processed in an automatic processor, the staff sits around waiting for the films to finish. This, of course, is not the case. While films are being processed, the staff moves on to other value-adding tasks.

A Obest of breedO approach

Film-based systems are the least expensive way to capture dental radiographs. They also are a reliable, proven way to store images. Films are human-readable: you don?t need to depend on a machine to view them. They can?t be made obsolete by technological changes. Dental X-ray films, properly processed and stored, can be expected to last for many years.

Other issues dentists should address when considering direct digital systems include:

* Are system components truly Oplug and playO? Manufacturers of digital dental-imaging equipment have recently agreed to a standard, called DICOM (Digital Imaging and Communications in Medicine), that will ensure files can be transmitted seamlessly among different brands or versions of hardware and software. Until this standard is incorporated in all equipment, it is up to dentists to verify that various pieces of a system can talk to one another.

* How will the use of the system impact staffing resources? Will the system permit a one-for-one replacement of an old task, or will it create new work?

Digital-imaging technology is not a new development in the medical industry.

Today, many hospitals and radiography clinics use digital technology for at least some portion of their diagnostic processes. Kodak? sells and supports several lines of hardware and software systems that harness digital technology for medical-imaging applications. However, at the present time, Kodak? feels the benefits of this technology for most dental applications have difficulty outweighing the costs, especially when compared to the value of film-based imaging.

It?s critical to select the right imaging technology for each application. An informed, balanced decision helps ensure that you can maintain image quality and affordable budgets, while tailoring a solution to fit your practice?s needs.

The author, Richard W. Brown, is the U.S. and Canada marketing manager, Dental Products, Health Imaging Division, of the Eastman Kodak Company. For more information about the division and its products, visit