Lorne Lavine, DMD
In last month's column, we looked at the different forms of digital radiography — scanners, phosphor plates, and digital sensors. Most offices spend a lot of time choosing their digital-radiography system, evaluating components for resolution, line pairs per millimeter, comfort, size, and, of course, cost. However, many of those dentists then will install the systems on older computers — with even older monitors — and are frequently disappointed with the results. The problem is that many do not realize that the computer monitor is the limiting factor in these situations.
Dentists purchase digital systems to not only eliminate film, chemicals, and mounts, but also to allow patients to participate in the diagnosis of their disease. When your monitor doesn't allow you to see the images clearly, you are fighting an uphill battle. For that reason, it would be wise to evaluate your monitors and see if a replacement is warranted.
Many factors should go into the process of selecting the best monitor for your office.
LCD vs. CRT
Up until about two years ago, CRT — or cathode-ray tube monitors — dominated the marketplace. These are the large, bulky, TV-type monitors that are still being used in most offices. More recently, LCD — or flat-panel monitors — have become increasingly popular. These monitors take up considerably less space, and by mounting them to an articulating arm, dentists can easily position the monitor wherever they choose. As prices have continued to drop and image quality has improved, the majority of offices installing new monitors are considering the flat panels. Dentists should be aware, though, that LCD monitors work differently than CRTs. For example, if you use a light pen with your older monitor, you will not be able to use this with an LCD.
Basically, I recommend getting the largest monitor that you can afford. The monitor that seems to give the best "bang for the buck" is the 17" LCD. While 15" models have dropped below $300, the 17" costs, on average, only $150 more and the extra screen size is noticeable for most people. One thing to consider with LCDs is the "native resolution." This is the resolution that the monitor is meant to run; any other resolution tends to produce a fuzzy image. For 17" monitors, it is typically 1280 X 1024 dpi. The reason this is important is that as the monitor size increases, so does the native resolution ... which makes the icons smaller. Some people will have trouble viewing and working with small icons.
Brightness and contrast
Although most monitor manufacturers will tout the brightness of their monitors in their marketing materials, for dental offices, the contrast ratio is actually the more important number. Brightness is measured in candela per square meter (cd/m2). Ideally, a monitor should be at 250 or greater. Contrast, though, is the key issue. A contrast ratio measures the difference in light intensity between the brightest white and the darkest black. High contrast ratio represents a much better color representation on the monitor than a lower contrast ratio. Obviously, this will come into play when trying to identify incipient interproximal caries on the monitor. You should look for a monitor with at least a 400:1 contrast ratio. Some of the better monitors have a 700:1 ratio or better.
Another specification that is often discussed with monitors is dot pitch. Dot pitch, or pixel pitch, is the amount of space, in millimeters, that separates two phosphors of the same color. If a monitor has a dot pitch of 0.27, there are 0.27 mm from one red phosphor to the nearest red phosphor in an adjacent pixel. Smaller is better. Most CRTs win this game, because the better monitors have an 0.22 dot pitch. That is why, at most dental meetings, the vendors demonstrating intraoral cameras will almost always show them on a small CRT monitor. LCDs, on the other hand, average about 0.27 to 0.29 mm dot pitch.
Dentists who would like to have a paperless office should evaluate all aspects of their systems, as they move towards a primarily digital dental office. Monitors are a key, but often overlooked, part of this process.
Lorne Lavine, DMD, practiced periodontics and implant dentistry for more than 10 years. He is an A+ Certified Computer Repair Technician, as well as Network+ Certified. He is the president of Dental Technology Consultants, a company that assists dentists in all phases of technology integration in the dental practice. He can be contacted by email at email@example.com or by phone at (866) 204-3398. Visit his Web site at www.thedigitaldentist.com.