Sometimes it's all too obvious that you have tooth decay: You're in pain or you can see a dark spot on your tooth. But in other cases, you may not even know there's a problem until you see your dentist.
That's because your dentist often can find early changes in your teeth that happen before a cavity develops. At first, the tooth structure softens. Sometime, a white spot appears.
How can your dentist find these early changes in your teeth that could lead to cavities? The traditional ways are to use X-rays or to examine your teeth and use an explorer, a metal tool that ends in a point. If the explorer "sticks" in a tooth, there may be early damage to the tooth structure.
Now, newer technologies are on the market and are being used by some dentists. Do these devices really do a better job than a pair of experienced eyes, an explorer and an X-ray? And if your dentist finds a sign of early decay, does it need to be treated right away?
Digital Imaging Fiber-Optic Trans-Illumination (DIFOTI)®
DIFOTI technology uses computers to collect images of your teeth while a light is shined behind them. Softened (demineralized) tooth areas can appear darker than healthy areas, so dentists can use the images to help them find early problems. The technique is similar to X-ray but does not use radiation.
Collecting images with DIFOTI takes more time than with X-rays because the camera has to be placed accurately on each tooth to collect the image. The technology is relatively simple to use, but the images must still be interpreted by a dentist, which leaves room for differences of opinion.
Digital Imaging: DIAGNOdent®
DIAGNOdent uses a laser to collect information. A handheld laser probe is shined on each tooth. The laser beam is absorbed by each tooth and then leaves the tooth again as fluorescent light. Solid tooth structure gives off very little fluorescent light, but damaged parts of a tooth and bacteria give off more. Information from each tooth is transmitted to a control unit, which looks something like a digital clock radio.
Studies have found that this technique helps diagnose early decay in the underlayer of the tooth (the dentin) whbefore a cavity develops in the outer, visible layer (enamel). DIAGNOdent can also be used to follow a suspicious tooth or teeth over time and see if the values change. Its manufacturer claims the device is 90% accurate.
Quantitative Light-Induced Fluorescence (QLF)™
Of these three technologies, QLF is the newest. It uses a light source, camera, fluorescent dye and computer software. The camera acquires images of each tooth, and the software analyzes the images and provides information about possible mineral loss.
The technology can detect early decay in primary (baby) and permanent teeth, as well as early decay that is close to fillings, crowns or orthodontic hardware.
QLF is useful for finding caries in people at high risk of decay and for confirming that teeth are healthy in people at low risk. However, it can miss early decay in high-risk people and can identify low-risk people as having decay when they really don't.
©2002-2005 Aetna, Inc. All rights reserved.
Reviewed by the faculty of Columbia University College of Dental Medicine