Taking Shades
There are many different visual aids present in today’s market that can assist us in choosing the correct shade for our patient from hand held lights to computerized spectrophotometers loaded with a database of different shade guide systems. However there are a few basic tools that can be of great assistance that require a minimum investment.
Color Corrected Lights
Most scientific information states that northern daylight at 12 noon is the ideal setting for correct color matching. Obviously this is an unrealistic situation for most dental practices. A color temperature of 5500˚ Kelvin is ideal for color rendering. Light at this temperature is described as having a medium temperature feel and is considered to be “white” light. The use of color corrected fluorescent lights that produce a temperature of approximately 5500˚ Kelvin is one way of closely duplicating natural daylight. They are readily available in 4 foot tubes to fit most ceiling fixtures and are easy to install. We have installed these throughout our laboratory and they provide a pleasant working environment in addition to the benefits of color matching. You should consider doing one operatory at a minimum and use it as a designated room for shade taking. Remember that surrounding colors, walls, bibs, smocks, etc. can greatly influence color perception so try to keep them neutral.
Digital Photography
The quality of digital cameras has greatly advanced over the last few years and they have become much more affordable as well. Photos can be printed at the office and sent with the case or emailed to the lab. While they cannot be used for exact shade matching they are a great tool in providing the ceramist a visual picture of ‘what is going on with this shade’. Individual characterizations, amount of translucency, darker gingival 1/3, and check lines are now a more realistic goal instead of guess work. We would suggest a digital SLR with a macro lens and at least 6 mega pixels of resolution for best results.
Shade Guides
There are many different shade guides available to all of us today but the one that remains the standard is the Vita Classic (A-1 thru D-4) from Vident. Most major porcelain manufacturers make their ceramic material keyed to this system. The introduction of the Vita 3D shade guide has generated a great deal of interest, but only Vident produces ceramic powders to match this guide. Although it is a great concept, labs that do not use Vita porcelains are forced to devise a formula of their material to match this shade guide which is not always a predictable science. We would recommend using the Classic shade guide whenever possible, but understand that sometimes we must deviate to achieve better communication. |