Colour My World
The young patient comes in with the right central fractured 45 degrees with an exposure.
by Paul Feuerstein, DMD
For more on this topic, go to www.dentaleconomics.com and search using the following key words: shade-matching devices, XRite Corporation, Vita, Olympus, shade guide, Dr. Paul Feuerstein.
The young patient comes in with the right central fractured 45 degrees with an exposure. After performing emergency endo treatment, you are now faced with the core and a single crown — you must match the centrals. Even with the newest all-ceramic materials, an exact match puts a knot in the stomach of even the staunchest practitioners.
In some situations, you can send a patient to a lab and have the case custom matched. Some labs, like Mitch Dental in Muncie, Ind., send a technician with a staining kit and oven and do the custom colors in the office. Is there a digital solution? There have been digital shade-taking devices for years, but they have been large, expensive and complex.
Three new units, though, may change this landscape. These three devices are also helpful if you are matching shade for composite restorations.
X-Rite Corporation manufactures the industrial units seen in paint departments of retail stores and auto body shops. X-Rite has offered ShadeVision, but the company's new unit, Shade-X, lists for $995.
With Shade-X, a small tip is placed against an area of the enamel, and the shade of that 3 mm area is displayed on the unit. You can choose several spots — usually cervical, middle, and incisal — and send this information to the lab. The more spots you take, the more precise the shade, although overdoing it can lead to confusion at the lab. It makes sense to augment this information with a digital photo or with “The Ladder” (to be discussed later).
Vita (Vident.com), which features EasyShade, has simplified this system and reduced its size. The wireless handheld device (EasyShade Compact) displays the shade information on a small screen in the unit. Like Shade-X, the operator can take multiple spots on the tooth to generate a shade map. Simultaneously, Vita has introduced a new 3D Master Shade guide, which is similar to the existing model but better organized based on customer input. It is time to throw out the old ABCD Vita shade guide.
Finally, Olympus has debuted the CrystalEye. This unit is far more than a shade system. It is actually a digital camera with a built-in spectrophotometer that is capable of taking photos of single teeth, as well as full arch and full face.
The shade system is in effect when a single-tooth photo is taken. Software in the computer complements the spectrophotometer in the acquisition unit. A photo is taken of the tooth and downloaded via a USB connection. This produces a map of the tooth that is divided into horizontal thirds. Each section is given a shade and a chart shows how close it is to the actual shade. A graph showing how much darker or lighter the tooth is from the shade tab is displayed with the tooth in a splitscreen view.
There are other uses, such as charting the degree a tooth has responded to bleaching, as well as documentation for before-and-after restorative treatments. Thus, the cost of this unit is significantly more than the shade units due to the differences between the two types of units.
Another option is using digital photos of a tooth and shade guide to transmit information to the technician. The problem with this option is that the color may not be a precise representation of the actual shade due to differences in computer monitors.
The program Clear Match (clearmatch.com) uses a computer algorithm to correlate the precise shade from a digital photo with a shade guide. The “trick” is the use of a pure black-and-white color chip in the shade photo. The computer “knows” black and white, and maps the precise shade on the screen. This gives the lab an accurate shade match.
An interesting nondigital solution is a shade guide called “The Ladder.” It is reminiscent of a “fan” of colors found at a paint department. But instead of a variety of colors, there are photos of teeth with a variety of characteristics that can be difficult to explain to a technician.
There are pictures of decalcification spots, extremely translucent incisal edges, craze lines, and other nonshade- related characteristics. The dentist buys a set of two and sends one off to the lab (unless the lab already has one) with the case. Get a better understanding of The Ladder by visiting www.4theladder.com.
Of course, the human eye of the dentist or another staff member still seems to be the most common system. Some say that technology is there for the sake of being there. Nonetheless, if you want the help, the tech side is available to assist you.
Dr. Paul Feuerstein installed one of dentistry's first computers in 1978. For more than 20 years, he has taught technology courses. A mainstay at technology sessions, Dr. Feuerstein is an ADA seminar series speaker. A general practitioner in North Billerica, Mass., since 1973, Dr. Feuerstein maintains a Web site (www.computersindentistry.com) and can be reached by e-mail at email@example.com.