Image Number 3 for United States Patent #6030209.
The present invention relates to a method for preparing the color of a dental restoration using a spectrophotometer and a unique color system for porcelain dental restorations which enables a dentist or technician to manipulate the various color components of the porcelain, hue, chroma, value, and translucency, independently. Color component deltas between consecutive colors in the powder sets are equidistant, with the difference in values being linear in color space. This enables simplified, exact matching of a specified color component value. The method comprises illuminating an abutting tooth with light, gathering reflected light, converting the gathered light to analog signals, correct for ambient light interference, translucency effects (if necessary) and varying illumination, using the result to obtain accurate color component values, and employing those values to chose and, where necessary, mix the appropriate powers to obtain the correct color porcelain for the desired dental restoration.