The normal distribution of color is to be slightly darker at the gingival margin or gum line. This is due to the fact that the enamel color and thickness determines the tooth color in the top half of the tooth and the dentin color more so in the bottom half. The enamel is thickest and covers the color of the dentin well in the top of the tooth. In the bottom half it begins to thin and eventually disappears just beyond the gum line.
So in the bottom half, the dentin color begins to dominate the crown color.To maintain a natural appearance a gradual darkening of the tooth is reproduced in most
crowns to mimic the gradual thinning of the enamel. If this tooth is visible in your smile you should match it as closely as possible to the teeth around it. Or you may be get lots of questions from people about your new crown.
