James Fondriest, DDS
Accurately reproducing the unique characteristics of a single maxillary central incisor so that the artificial replacement is perceived as “natural” can be the biggest challenge in restorative dentistry. This challenge comes at several levels. First, the practitioner needs to have an understanding of what factors go into achieving a good match as well as some basic knowledge of the nomenclature of light science in order to communicate what is seen. Second, the practitioner is responsible for creating a protocol to accurately assess what is happening when light hits the surface of the tooth to create its appearance. There are ways to enhance what we see visually or photographically in the mouth by lessening metamerism, afterimages, and other visual distortions.
Third, the practitioner needs to develop written, graphic, and photographic communication devices that are more comprehensive and less confusing. For example, there is no common dental standard for communicating the degree of translucency, hypocalcification of enamel, or varying degrees of surface luster. If we had to describe in great detail the teeth shown inFig 1 without photography, how many words would it take to deliver a nonconfusing synopsis? And last, laboratory staff needs to develop their skills along with the practitioner partner because all of the levels of communication conveyed to the lab must also be recognized and understood in the photographs.
It is important to realize that matching the hue and chroma is fifth or sixth in importance on the list of things to match when constructing a prosthetic replacement.1 A person would have to be fairly close to detect subtle differences in hue; yet disparities in surface morphology, value, and opacity can be seen from 4 or 5 feet away or more. Disparate tooth silhouettes or perimeter shapes of the teeth can be seen from even 10 feet away. The order of importance while matching a single maxillary central is (1) silhouette or perimeter shape, (2) surface morphology and texture, (3) value, (4) translucency or opacity, (5) chroma, and (6) hue.